02580nas a2200169   4500008004100000022001400041245014400055210006900199260007100268300001400339490000700353520184400360100002502204700003002229700003002259856012102289       2006                        eng d  a0897-475600aAutoreduction of cyanoferrate(III) ions in a polymer electrolyte membrane: all solid state electrochemical and spectroscopic investigations0 aAutoreduction of cyanoferrateIII ions in a polymer electrolyte m  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a5244-52520 v183 a<p>The effect of dielectric confinement on proton-coupled electron-transfer behavior and spectroscopic properties of cyanoferrate ions in a polymer electrolyte membrane (Nafion) has been investigated in an ``all-solid-state'' electrochemical cell, using techniques such as cyclic voltammetry, zero current chronopotentiometry, electrochemical impedance, diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), UV-visible spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron spin resonance spectroscopy (ESR). From the above investigations, we found that cyanoferrate(III) ions undergo autoreduction in the ionomer matrix, for which a sulfonate-coupled mechanism has been proposed. This report demonstrates the effectiveness of the micellar interface in tuning the redox potential of the confined ions. A systematic analysis of the cyclic voltammetry and impedance data for the [Fe(CN)(6)](4)(-)- containing Nafion membrane enables the estimation of a standard rate constant for [Fe(CN) 6](4-) oxidation, k(o), as 5.44 x 10(-6) cm/s and a diffusion coefficient, D-o, as 1.3 x 10(-12) cm(2)/s. A similar calculation yields a value of 4.8 x 10(-12) cm(2)/s for the diffusion coefficient of protons and 9.1 x 10(-6) cm/s for the standard rate constant for hydrogen oxidation. The similarity in mass-transfer coefficients calculated for protons and [Fe(CN)(6)](4-) ions suggests a proton-coupled electron-transfer mechanism for the [Fe(CN)(6)](4-)/[Fe(CN)(6)](3-) couple. The results of the above investigations could have direct technological relevance for deciding catalyst materials having redox compatibility with the polymer electrolyte, especially in the preparation of catalyst-coated membranes (wherein the fuel-cell catalyst is directly coated onto the polymer membrane instead of on the carbon support).</p>1 aParthasarathy, Meera1 aGopinath, Chinnakonda, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/autoreduction-cyanoferrateiii-ions-polymer-electrolyte-membrane-all-solid-state-101479nas a2200217   4500008004100000022001400041245008500055210006900140260008000209300001400289490000700303520067000310100002500980700002401005700002101029700002201050700002301072700002001095700003001115856011601145       2006                        eng d  a0957-448400aField emission studies of novel ZnO nanostructures in high and low field regions0 aField emission studies of novel ZnO nanostructures in high and l  aDIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcJUN  a2730-27350 v173 a<p>A study of the field emission characteristics of novel structures of ZnO, namely marigolds, multipods and microbelts, has been carried out in both the close proximity configuration and the conventional field emission microscope. The use of a conventional field emission microscope overcomes the drawback of arc formation at high field values. The nonlinearity in the Fowler - Nordheim ( F - N) plot, a characteristic feature of semiconductors has been observed and explained on the basis of electron emission from both the conduction and the valence bands. The current stability exhibited by these structures is also promising for future device applications.</p>1 aRamgir, Niranjan, S.1 aLate, Dattatray, J.1 aBhise, Ashok, B.1 aMulla, Imtiaz, S.1 aMore, Mahendra, A.1 aJoag, Dilip, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/field-emission-studies-novel-zno-nanostructures-high-and-low-field-regions-002379nas a2200265   4500008004100000022001400041245008500055210006900140260009500209300001000304490000800314520144900322653002001771653002301791653001501814653001401829653001101843653001901854100002501873700003001898700002201928700002101950700002601971856011601997       2007                        eng d  a0006-291X00aAll-solid-state' electrochemistry of a protein-confined polymer electrolyte film0 aAllsolidstate electrochemistry of a proteinconfined polymer elec  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcDEC  a86-910 v3643 a<p>Interfacial redox behavior of a heme protein (hemoglobin) confined in a solid polymer electrolyte membrane, Nafion (a perfluoro sulfonic acid ionomer) is investigated using a unique `all-solid-state' electrochemical methodology. The supple phase-separated structure of the polymer electrolyte membrane, with hydrophilic pools containing solvated protons and water molecules, is found to preserve the incorporated protein in its active form even in the solid-state, using UV-visible, Fluorescence (of Tryptophan and Tyrosine residues) and DRIFT (diffuse reflectance infrared Fourier transform) spectroscopy. More specifically, solid-state cyclic voltammetry and electrochemical impedance of the protein-incorporated polymer films reveal that the Fe2+-form of the entrapped protein is found to bind molecular oxygen more strongly than the native protein. In the `all-solid-state' methodology, as there is no need to dip the protein-modified electrode in a liquid electrolyte (like the conventional electrochemical methods), it offers an easier means to study a number of proteins in a variety of polymer matrices (even biomimetic assemblies). In addition, the results of the present investigation could find interesting application in a variety of research disciplines, in addition to its fundamental scientific interest, including protein biotechnology, pharmaceutical and biomimetic chemistry. (C) 2007 Elsevier Inc. All rights reserved.</p>10aall-solid-state10acyclic voltammetry10ahemoglobin10aImpedance10aNafion10aredox behavior1 aParthasarathy, Meera1 aPillai, Vijayamohanan, K.1 aMulla, Imtiaz, S.1 aShabab, Mohammed1 aKhan, Mohammad, Islam  uhttps://library.ncl.res.in/content/all-solid-state-electrochemistry-protein-confined-polymer-electrolyte-film-001371nas a2200205   4500008004100000022001400041245006700055210006700122260012500189300002300314490000700337520058300344100002600927700002300953700002000976700002500996700002201021700003001043856009201073       2007                        eng d  a0003-695100aEnergy analysis of field emitted electrons from a ZnO tetrapod0 aEnergy analysis of field emitted electrons from a ZnO tetrapod  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAPR  aArticle No. 1621020 v903 a<p>The experimental total energy distribution (TED) of the field emitted electrons from a single pod of a ZnO tetrapod has been obtained, exhibiting a two-peak feature. The energy difference between the two peaks in the TED is found to be nearly equal to the band gap of the bulk ZnO. The results show that field emitted electrons originate from both the conduction and valence bands. The peak position dependence on the applied voltage has also been observed. In the present case, the size of the ZnO tetrapod is not small enough to reflect the quantum confinement effects.</p>1 aAl-Tabbakh, Ahmed, A.1 aMore, Mahendra, A.1 aJoag, Dilip, S.1 aRamgir, Niranjan, S.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/energy-analysis-field-emitted-electrons-zno-tetrapod01611nas a2200277   4500008004100000022001400041245005900055210005800114260007300172300001400245490000800259520071800267653002400985653001901009653002901028653000901057653000901066100002101075700002401096700002501120700002301145700002201168700003001190700002001220856009301240       2007                        eng d  a0169-433200aField emission investigations of RuO2-doped SnO2 wires0 aField emission investigations of RuO2doped SnO2 wires  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a9159-91630 v2533 a<p>Field emission studies of a bunch and a single isolated RuO2:SnO2 wire have been performed. A current density of 5.73 x 10(4) A/cm(2) is drawn from the single wire emitter at an applied field of 8.46 x 10(4) V/mu m. Nonlinearity in the Fowler-Nordheim (F-N) plot has been observed and explained on the basis of electron emission from both the conduction and the valence bands of the semiconductor. The current stability recorded at the preset value of 1.5 LA is observed to be good. Overall the high emission current density, good stability and mechanically robust nature of the RuO2:SnO2 wires offer advantages as field emitters for many potential applications. (c) 2007 Elsevier B.V. All rights reserved.</p>10adoped semiconductor10afield emission10afield enhancement factor10aRuO210aSnO21 aBhise, Ashok, B.1 aLate, Dattatray, J.1 aRamgir, Niranjan, S.1 aMore, Mahendra, A.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.1 aJoag, Dilip, S.  uhttps://library.ncl.res.in/content/field-emission-investigations-ruo2-doped-sno2-wires-002649nas a2200193   4500008004100000022001400041245009900055210006900154260007100223300001600294490000800310520188000318100002502198700002502223700002302248700002202271700003002293856013202323       2007                        eng d  a1932-744700aSurface-state-mediated electron transfer at nanostructured ZnO multipod/electrolyte interfaces0 aSurfacestatemediated electron transfer at nanostructured ZnO mul  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a13092-131020 v1113 a<p>Redox kinetics of cyanoferrate(III) species adsorbed at an n-type ZnO multipod/electrolyte interface is explored using electrochemical techniques like cyclic voltammetry and impedance spectroscopy. The electrochemical impedance results are analyzed using a fluctuating energy level model, assuming isoenergetic tunneling of majority carriers through the Helmholtz layer. A shift in the slope of Mott-Schottky plots (C-sc(-2) versus E) together with evidence from cyclic voltammetry shows that the electron-transfer process is mediated by surface states formed because of the adsorption of ferricyanide ions (as evident from the results of Fourier transform infrared spectroscopy). More significantly, the pH of zero charge (point of zero zeta potential, pzzp) of ZnO multipods is found to be 4.5 (from capacitance vs pH plots) compared to that of bulk ZnO (pH 9.5), which could be explained on the basis of a lowering in the work function of the nanostructured semiconductor and its consequent susceptibility to the formation of surface states. This is in excellent agreement with our earlier observation of ultralow threshold field emission with this material in the light of the linear dependence of pzzp with work function of the electrode material. The flat-band potential of the nanostructures is found to be 200 mV more negative than that reported for bulk n-type ZnO electrodes, indicating a higher doping density in the former. A three-dimensional mapping of charge distribution in the surface states is attempted by correlating the capacitance response of the system subjected to a sinusoidal potential modulation to the semiconductor electrode with that resulting from a systematic variation of the redox potential of the dissolved acceptor (achieved by varying the pH of the electrolyte) which further reveals the polyenergetic nature of the surface states.</p>1 aParthasarathy, Meera1 aRamgir, Niranjan, S.1 aSathe, Bhaskar, R.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/surface-state-mediated-electron-transfer-nanostructured-zno-multipodelectrolyte-interfaces-001839nas a2200193   4500008004100000022001400041245010600055210006900161260007100230300001600301490000800317520107100325100002501396700002101421700002301442700002201465700003001487856012801517       2007                        eng d  a1932-744700aTemplate-assisted synthesis of ruthenium oxide nanoneedles: electrical and electrochemical properties0 aTemplateassisted synthesis of ruthenium oxide nanoneedles electr  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV  a16593-166000 v1113 a<p>We here demonstrate the formation of bundles of RuO2 nanoneedles (ca. 100 nm diameter) by a templateassisted electrodeposition from aqueous RuCl3 solution under potentiostatic conditions at room temperature. Cyclic voltammetric measurements in 0.5 M H2SO4 show significantly higher redox-related charging behavior for the RuO2 nanoneedles compared to that of the commercial sample, which is also supported by the electrochemical impedance data. A comparison of the specific capacitance reveals a higher value for nanoneedles (3 F/g instead of 0.4 F/g for the bulk), which has been explained on the basis of enhanced reactivity. More interestingly, electrical transport measurements reveal a transition from metallic to semiconducting behavior especially at low-temperature caused by an impurity scattering mechanism. We anticipate that the present simple route for the fabrication of RuO2 nanostructures will be useful to exploit their potentials in various fields such as electrocatalysis, nanoelectronics, and more importantly for designing supercapacitors.</p>1 aSubhramannia, Mahima1 aBalan, Beena, K.1 aSathe, Bhaskar, R.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/template-assisted-synthesis-ruthenium-oxide-nanoneedles-electrical-and-electrochemical-001922nas a2200205   4500008004100000022001400041245009300055210006900148260007300217300001400290490000800304520115100312653002101463653002201484653001401506653001501520100002801535700003001563856012301593       2008                        eng d  a0169-433200aEfficient route towards the covalent functionalization of single walled carbon nanotubes0 aEfficient route towards the covalent functionalization of single  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a4936-49430 v2543 a<p>A simple and efficient method of chemical functionalization of both single and multiwalled carbon nanotubes has been discussed to give enhanced water solubility by rapidly and efficiently generating an appreciable amount of hydrophilic functional groups using microwave radiation. Surface functionalization containing more than 30 wt% of oxygen has been achieved, resulting into solubility of 2-5 mg/mL. Further covalent functionalization of such soluble SWNTs provides a remarkable degree of aniline functionalization through amidation, where the formation of polyaniline has been avoided. Functionalization of SWNTs is confirmed by techniques like electron microscopy, Fourier transform infrared spectroscopy, thermogravimetry, Raman spectroscopy, cyclic voltammetry and impedance spectroscopy. Electrochemical analysis suggests an enhanced double layer capacitance (similar to 110 F/g) of nanotubes after microwave treatment. Aniline functionalization of SWNTs shows possible variations on the nanotube topography with concomitant formation of a dynamic polymer layer on the nanotube surface. (C) 2008 Elsevier B.V. All rights reserved.</p>10aCarbon nanotubes10aFunctionalization10aMicrowave10asolubility1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/efficient-route-towards-covalent-functionalization-single-walled-carbon-nanotubes-002299nas a2200241   4500008004100000022001400041245011800055210006900173260009200242300001400334490000600348520130800354653002301662653004401685653005201729653001501781653003201796100002301828700002301851700002201874700003001896856013101926       2008                        eng d  a1533-488000aElectrochemical sensing of sulphur dioxide: a comparison using dodecanethiol and citrate capped gold nanoclusters0 aElectrochemical sensing of sulphur dioxide a comparison using do  a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScJUN  a3184-31900 v83 a<p>A comparison of cyclic voltammograms of dodecanethiol (DDT) capped Au nanoclusters (5.0 +/- 0.5 nm) and trisodium citrate (Cit) capped Au nanoclusters (similar to 10-15 nm) modified glassy carbon electrode shows a dramatic variation in the current when exposed to a small amount of sulphur dioxide. This is explained using the electrocatalytic properties of Au nanoclusters towards the oxidation of SO2, thus facilitating the fabrication of electrochemical sensors for the detection of SO2. The intrinsic redox changes observed for gold nanocluster-modified glassy carbon electrodes disappear on passing SO2, despite a dramatic current increase, which indeed scales up with the amount of dissolved SO2. Interestingly, a complete rejuvenation of the redox behavior of gold is also observed on subsequent removal of SO2 from the solution by passing pure nitrogen for 15 minutes. Further, these nanoclusters when characterized with X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) after SO2 passage reveal a variety of SO2 adsorption modes on gold surface. XP spectra also show a shift of 1.03 eV towards higher binding energy indicating a strong adsorption of SO2 gas, while FTIR gives conclusive evidence for the interaction of SO2 with gold nanoparticles.</p>10acyclic voltammetry10aFourier transform infrared spectroscopy10amonolayer protected gold nanoclusters (Au-MPCs)10aSO2 sensor10aX-ray photoelectron spectra1 aSathe, Bhaskar, R.1 aRisbud, Mandar, S.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/electrochemical-sensing-sulphur-dioxide-comparison-using-dodecanethiol-and-citrate-capped-001441nas a2200217   4500008004100000022001400041245006600055210006600121260012500187300001100312490000700323520062500330100002300955700002800978700002201006700003001028700002401058700002301082700002001105856009801125       2008                        eng d  a0003-695100aEnhanced field emission from hexagonal rhodium nanostructures0 aEnhanced field emission from hexagonal rhodium nanostructures  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJUN  a2531060 v923 a<p>Shape selective synthesis of nanostructured Rh hexagons has been demonstrated with the help of a modified chemical vapor deposition using rhodium acetate. An ultralow threshold field of 0.72 V/mu m is observed to generate a field emission current density of 4 x 10(-3) mu A/cm(2). The high enhancement factor (9325) indicates that the origin of electron emission is from nanostructured features. The smaller size of emitting area, excellent current density, and stability over a period of more than 3 h are promising characteristics for the development of electron sources. (C) 2008 American Institute of Physics.</p>1 aSathe, Bhaskar, R.1 aKakade, Bhalchandra, A.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.1 aLate, Dattatray, J.1 aMore, Mahendra, A.1 aJoag, Dilip, S.  uhttps://library.ncl.res.in/content/enhanced-field-emission-hexagonal-rhodium-nanostructures-001316nas a2200181   4500008004100000022001400041245012500055210006900180260007100249300001600320490000800336520056000344100002800904700001700932700002800949700003000977856012701007       2008                        eng d  a1932-744700aHighly selective catalytic hydrogenation of arenes using rhodium nanoparticles supported on multiwalled carbon nanotubes0 aHighly selective catalytic hydrogenation of arenes using rhodium  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a13317-133190 v1123 a<p>Rhodium nanoparticles (RhNPs; 4.9 +/- 0.4 nm) supported on multiwalled carbon nanotubes (Rh/MWNT), prepared by simple microwave treatment, show a remarkable catalytic activity for arene hydrogenation with enhanced turnover numbers of similar to 10000; disubstituted arenes show selective conversion of thermodynamically less favorable cis products (&gt;80%). A series of arenes have been tested using various Rh-based catalysts, and a comparison of the results with that of reported rhodium catalysts shows unique selectivity under mild conditions.</p>1 aKakade, Bhalchandra, A.1 aSahoo, Suman1 aHalligudi, Shivappa, B.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/highly-selective-catalytic-hydrogenation-arenes-using-rhodium-nanoparticles-supported-002167nas a2200193   4500008004100000022001400041245010500055210006900160260010600229300001200335490000700347520136800354100002801722700002001750700002501770700002301795700003001818856012501848       2008                        eng d  a0008-622300aHigh-purity synthesis of scrolled mats of multi-walled carbon nanotubes using temperature modulation0 aHighpurity synthesis of scrolled mats of multiwalled carbon nano  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcAPR  a567-5760 v463 a<p>Felt-like mats (6-7 mu m thick) of multimalled carbon nanotubes wrapped into scrolls have been synthesized by chemical vapor deposition from a toluene-ferrocene mixture using a temperature ramp from 680 degrees C to 550 degrees C in hydrogen-argon atmosphere. Thermogravimetric analysis reveals a very low catalyst content of ca. 1.25 wt% in the as-synthesized sample while, X-ray photo electron and Raman spectroscopies suggest the results matching with that of multiwalled carbon nanotubes. Considering, different time scales of various reactions and the diffusion of different reactants and products a tentative base growth mechanism has been proposed as per the available characterization data in conjunction with possible scrolling effects. Thermal expansion effects could explain a tentative mechanism for rolling action of sheets. Interestingly, electrical conductivity measurements as a function of temperature suggest a semiconducting behavior, despite being governed by different electron transport mechanisms with activation energies of 0.33 and 1.03 meV corresponding to two temperature ranges respectively. Cyclic voltammetry and electrochemical impedance analysis show a reversible redox behavior due to very low catalyst content and an irreversible etching of the Fe catalyst after acid treatment. (C) 2007 Elsevier Ltd. All rights reserved.</p>1 aKakade, Bhalchandra, A.1 aAllouche, Hatem1 aMahima, Subhramanyam1 aSathe, Bhaskar, R.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/high-purity-synthesis-scrolled-mats-multi-walled-carbon-nanotubes-using-temperature-002175nas a2200253   4500008004100000022001400041245011500055210006900170260008000239300001400319490000800333520125000341653002001591653002101611653001901632653000901651653002601660653001201686100002501698700001801723700001901741700003001760856013101790       2008                        eng d  a1618-264200aImaging the stomatal physiology of somatic embryo-derived peanut leaves by scanning electrochemical microscopy0 aImaging the stomatal physiology of somatic embryoderived peanut   aTIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANYbSPRINGER HEIDELBERGcJUL  a2227-22330 v3913 a<p>The stomatal physiology, chlorophyll distribution and photosynthetic activity of somatic embryo (SE)- and seedling-derived peanut plants grown in vitro (test tube-grown) and extra vitrum (soil-grown) are investigated using scanning electrochemical microscopy (SECM). This SECM imaging is performed in two different feedback modes, corresponding to oxygen evolution and chlorophyll distribution. More specifically, the oxygen evolution profiles of the in vitro leaves indicate important differences in leaf anatomy between the SE- and seedling-derived leaves. On the other hand, the chlorophyll distribution images show individual stomata of size ca. 27 +/- 5 mu m. Further studies on senescing (aged) leaves reveal interesting voltammograms that vary widely over the stomatal complexes and the surrounding tissues, probably due to the release of electroactive metabolites during chlorophyll breakdown when the leaves turn yellow. Thus, the present investigation could open up new opportunities for characterizing botanical systems using electroanalytical techniques. In addition, it could provide further insights into various areas of current relevance, including signal transduction, cell fate/differentiation and developmental biology.</p>10aleaf senescence10aoxygen evolution10aphotosynthesis10aSECM10asomatic embryogenesis10astomata1 aParthasarathy, Meera1 aSingh, Shweta1 aHazra, Sulekha1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/imaging-stomatal-physiology-somatic-embryo-derived-peanut-leaves-scanning-electrochemical-002611nas a2200253   4500008004100000022001400041245019100055210006900246260013700315300001200452490000700464520149700471653002201968653003001990653002102020653004202041653001202083653003102095100002602126700002102152700002802173700003002201856012602231       2008                        eng d  a0956-566300aInvertase inhibition based electrochemical sensor for the detection of heavy metal ions in aqueous system: application of ultra-microlelectrode to enhance sucrose biosensor's sensitivity0 aInvertase inhibition based electrochemical sensor for the detect  aOXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER ADVANCED TECHNOLOGYcDEC  a657-6640 v243 a<p>We are reporting fabrication and characterization of electrochemical sucrose biosensor using ultra-microelectrode (UME) for the detection of heavy metal ions (Hg(II), Ag(I), Pb(II) and Cd(II)). The working UME, with 25 mu m diameter, was modified with invertase (INV, EC: 3.2.1.26) and glucose oxidase (GOD, EC: 1.1.3.4) entrapped in agarose-guar gum. The hydrophilic character of the agarose-guar gum composite matrix was checked by water contact angle measurement. The atomic force microscopy (AFM) images of the membranes showed proper confinement of both the enzymes during co-immobilization. The dynamic range for sucrose biosensor was achieved in the range of 1 x 10(-10) to 1 x 10(-7) M with lower detection limit 1 x 10(-10) M at pH 5.5 with 9 cycles of reuse. The spectrophotometric and electrochemical studies showed linear relationship between concentration of heavy metal ions and degree of inhibition of invertase. The toxicity sequence for invertase using both methods was observed as Hg(2+) &gt; Pb(2+) &gt; Ag(+) &gt; Cd(2+). The dynamic linear range for mercury using electrochemical biosensor was observed in the range of 5 x 10(-10) to 12.5 x 10(-10) M for sucrose. The lower detection limit for the fabricated biosensor was found to be 5 x 10(-10) M. The reliability of the electrochemical biosensor was conformed by testing the spike samples and the results were comparable with the conventional photometric DNSA method. (C) 2008 Elsevier B.V. All rights reserved.</p>10aCo-immobilization10aElectrochemical biosensor10aHeavy metal ions10aInvertase (INV)-glucose oxidase (GOD)10aMercury10aUltra-microelectrode (UME)1 aBagal-Kestwal, Dipali1 aKarve, Meena, S.1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/invertase-inhibition-based-electrochemical-sensor-detection-heavy-metal-ions-aqueous-000833nas a2200217   4500008004100000022001400041245011100055210006900166260007700235300001400312490000700326653001500333653001400348653001400362653001300376653002100389100002100410700002800431700003000459856012600489       2008                        eng d  a1433-785100aPolymer electrolyte fuel cells using nafion-based composite membranes with functionalized carbon nanotubes0 aPolymer electrolyte fuel cells using nafionbased composite membr  aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB  a2653-26560 v4710afuel cells10amembranes10ananotubes10aPolymers10aproton transport1 aKannan, Ramaiyan1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/polymer-electrolyte-fuel-cells-using-nafion-based-composite-membranes-functionalized-001813nas a2200277   4500008004100000022001400041245007000055210006400125260006900189300001400258490000800272520089200280653002401172653001801196653002901214653002001243653001401263100002101277700002401298700002501322700002301347700002201370700003001392700002001422856009301442       2008                        eng d  a0040-609000aRuO(2) doped SnO(2) nanobipyramids on Si (100) as a field emitter0 aRuO2 doped SnO2 nanobipyramids on Si 100 as a field emitter  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcJUL  a6388-63910 v5163 a<p>Thin films of RuO(2): SnO(2) nanobipyramids have been grown on silicon (100) flat substrates, and their field emission behavior has been investigated. The field emission experiments have been performed in parallel plate configuration. In this experiment, the onset field for 0. 1 gA/ cm 2 current density has been found to be 0.2 V/mu m. The Fowler-Nordheim plot shows non-linear nature typical that of a semiconductor. The field enhancement factor has been estimated to be 35,600 cm(-1), indicating that the field emission originates from the nanometric features of the emitter. The current stability recorded at a preset value of I tA is observed to be good. Our field emission results on RuO(2): SnO(2) nanobipyramids indicate that, RuO(2): SnO(2) nanobipyramids are a potential candidate for futuristic field emission based devices. (c) 2008 Elsevier B.V. All rights reserved.</p>10adoped semiconductor10afield emitter10afield enhancement factor10aruthenium oxide10atin oxide1 aBhise, Ashok, B.1 aLate, Dattatray, J.1 aRamgir, Niranjan, S.1 aMore, Mahendra, A.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.1 aJoag, Dilip, S.  uhttps://library.ncl.res.in/content/ruo2-doped-sno2-nanobipyramids-si-100-field-emitter-002041nas a2200157   4500008004100000022001400041245007300055210006900128260011000197300001400307490000700321520139300328100002501721700003001746856010701776       2008                        eng d  a0959-942800aShape-dependent electrocatalytic activity of platinum nanostructures0 aShapedependent electrocatalytic activity of platinum nanostructu  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a5858-58700 v183 a<p>Since many metallic nanostructures with different shapes exhibit unique chemical and physical properties, a systematic attempt to synthesize these shape-controlled structures for property-shape correlation remains an important challenge in contemporary materials chemistry. Main difficulties like poor shape selectivity, low yield, presence of impurity phases, difficulty of separation, etc., are exacerbated since metallic structures have high surface energies which favour lower surface areas, and consequently many synthesis strategies, including the use of hard and soft templates and external nucleating agents, are being employed along with theoretical guidelines from density functional calculations on simpler systems. One of the important application areas where these structures have gained profound attention is in electrocatalysis, where the kinetics of many structure-sensitive reactions of technological relevance have been experimentally observed to show drastic changes with shape especially in the nanosize domain, at least in one dimension. Considering their scientific and technological importance, this feature article provides an overview of the recent progress on the shape-controlled synthesis of metallic nanostructures with special emphasis on platinum, and their crucial role in the electrocatalysis of anodic reactions for polymer electrolyte fuel cells.</p>1 aSubhramannia, Mahima1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/shape-dependent-electrocatalytic-activity-platinum-nanostructures-002473nas a2200169   4500008004100000022001400041245012700055210006900182260007100251300001400322490000700336520175100343100002502094700002802119700003002147856012602177       2008                        eng d  a0024-929700aTuning the transport properties of Poly(oxyethylene)bisamine - Nafion polyelectrolyte complexes by dielectric manipulation0 aTuning the transport properties of Polyoxyethylenebisamine Nafio  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a3653-36580 v413 a<p>Polyelectrolyte complexes (PECs) of Nafion-H+, a perfluorosulfonic acid ionomer, and Poly(oxyethylene)bisamine (Polyox) were synthesized, and the effect of electrostatic interactions on the physicochemical properties of the individual components was studied using a combination of spectroscopic and electrochemical techniques. More specifically, the pristine PECs were extensively characterized using viscosity, surface tension, and pH measurements and diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy and their transport properties were investigated using cyclic voltammetry and electrochemical impedance spectroscopy, by employing [Fe(CN)(6)](3-) as a redox probe. Acid-base interaction between Nafion and Polyox is evident from pH measurements of the blend solutions, which indicate salt formation at a 50:50 composition, supported further by the existence of a maximum in the plot of surface tension versus blend composition. DRIFT spectra of the PEC membranes indicate subtle changes in the ionic environment and a transition from a state of medium hydration to a partially dehydrated state of the parent ionomer, Nation, after complexation with Polyox. Further evidence for polyelectrolyte-polyelectrolyte association is obtained from cyclic voltammetry, which shows that the interaction between the redox active chromophore, [Fe(CN)(6)](3-), and the pendent sulfonate groups of Nafion is minimized by complexation with the oppositely charged polyelectrolyte Polyox. The water-soluble nature of these PECs along with the tunable range of properties with blend composition could qualify them as suitable candidates for developing stimuli-responsive polymer systems for pharmaceutical and environmental applications.</p>1 aParthasarathy, Meera1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/tuning-transport-properties-polyoxyethylenebisamine-nafion-polyelectrolyte-complexes-001380nas a2200157   4500008004100000022001400041245009500055210006900150260007100219300001400290490000800304520073000312100002801042700003001070856012201100       2008                        eng d  a1932-744700aTuning the wetting properties of multiwalled carbon nanotubes by surface functionalization0 aTuning the wetting properties of multiwalled carbon nanotubes by  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a3183-31860 v1123 a<p>A simple strategy of chemical functionalization is employed here for controlling the wettability of multiwalled carbon nanotube films from superhydorphobic (156 degrees) to nearly hydrophilic (40 degrees), which further shows superhydrophilicity with a water contact angle of about 0 degrees within 2 s. The hydrophobic surface (water contact angle 145 degrees) in case of nitric-acid-treated MWCNT bucky paper shows an unusual pinning action even at a tilt angle of 45 degrees, following Wenzel behavior of the surface. The variation in the wetting properties of MWCNT bucky paper using such surface designing strategies provides controlled heterogeneity on the surface with no or minimal effect on surface roughness.</p>1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/tuning-wetting-properties-multiwalled-carbon-nanotubes-surface-functionalization-002340nas a2200193   4500008004100000022001400041245014100055210006900196260007100265300001400336490000700350520152700357100002101884700002501905700003001930700002401960700003001984856013202014       2009                        eng d  a0743-746300aDomain size manipulation of perflouorinated polymer electrolytes by sulfonic acid-functionalized MWCNTs to enhance fuel cell performance0 aDomain size manipulation of perflouorinated polymer electrolytes  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL  a8299-83050 v253 a<p>The application of sulfonic acid-functionalized multiwalled (s-MWNT) carbon nanotubes to manipulate the hydrophilic domain size of Nafion membranes is explored here as an option for tuning the proton conductivity of polymer electrolyte membranes for hydrogen-oxygen fuel cells. The electrochemical impedance experiments provide preliminary evidence of increased proton conductivity, while small-angle X-ray scattering measurements line. out enhanced ionic cluster domain size in these composite membranes as the central reason for higher conductivity (70 angstrom for the optimum composite membrane vs 50 angstrom for Nafion 115) values. Scanning electrochemical microscopy indicates synergistic interaction between the sulfonic acid functional groups present in the Nation membrane and those on the nanotube surface. More interestingly, the nanotube-tailored Nafion membranes ameliorate the performance of fuel cells as confirmed by measurements at a sin le-cell level, which reveal a maximum power density of 380 mW cm(-2), higher than those of Nafion 115 (250 mW cm(-2)) and recast Nafion (230 mW cm-2) membranes. Thus, in addition to providing an elegant means of controlling the ionic cluster size, the strategic approach of using CNT both as an anchoring backbone for -SO(3)H groups to enrich proton conductivity and as a blending agent to improve the mechanical characteristics of the Nafion phase might be helpful in alleviating many critical problems associated with the use of commercial Nafion membranes.</p>1 aKannan, Ramaiyan1 aParthasarathy, Meera1 aMaraveedu, Sreekuttan, U.1 aKurungot, Sreekumar1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/domain-size-manipulation-perflouorinated-polymer-electrolytes-sulfonic-acid-functionalized-001771nas a2200265   4500008004100000022001400041245006200055210006100117260007300178300001400251490000700265520091100272653002201183653001301205653001901218653000901237100002101246700002401267700002301291700002301314700002201337700003001359700002001389856009601409       2009                        eng d  a1293-255800aField emission investigation of single Fe-doped SnO2 wire0 aField emission investigation of single Fedoped SnO2 wire  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a1114-11170 v113 a<p>Tin oxide submicronwires doped with Fe element were prepared by the thermal evaporation method. Morphological and structural characterizations revealed wires with sub micron size and crystalline in nature. The field electron emission from the single Fe:SnO2 wire was carried out in conventional field emission microscope. The Fowler-Nordheim plot obtained from I-V characteristics of the wire showed a linear behavior typical that of metal. The field enhancement factor estimated from the slope of the F-N plot is 7455 cm(-1), indicating that the field emission is from nanometric features of the emitter. A current density of 10 A/cm(2) has been obtained at an applied field of 4.845 x 10(3) V/mu m. The field emission current-time record at a current level of 1 mu A for more than 3 h duration is promising for various field emissions based applications. (C) 2009 Published by Elsevier Masson SAS.</p>10aCurrent stability10aFe doped10afield emission10aSnO21 aBhise, Ashok, B.1 aLate, Dattatray, J.1 aSathe, Bhaskar, R.1 aMore, Mahendra, A.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.1 aJoag, Dilip, S.  uhttps://library.ncl.res.in/content/field-emission-investigation-single-fe-doped-sno2-wire-002367nas a2200217   4500008004100000022001400041245015500055210006900210260010200279300001200381490000800393520150000401653002301901653001201924653001101936653001301947653000901960100002501969700003001994856012502024       2009                        eng d  a0253-413400aImaging hydrogen oxidation activity of catalyst-coated perfluoro sulfonic acid-polymer electrolyte membranes using scanning electrochemical microscopy0 aImaging hydrogen oxidation activity of catalystcoated perfluoro   aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScSEP  a719-7250 v1213 a<p>Scanning Electrochemical Microscopy (SECM) is a unique technique for studying fast heterogeneous kinetics and to map reactivity gradients along the surface of an electrocatalyst, especially when it involves multiple surface sites of varying reactivity. It combines the dual advantages offered by ultramicroelectrode (UME) voltammetry in terms of reduced ohmic drop and insignificant double layer charging contribution with the advantages of imaging by rastering the UME across an electro-active surface. In this work, we demonstrate these distinctive features of SECM in evaluating reactivity gradients on catalyst (Pt/C) coated NafionA (R) films towards hydrogen oxidation activity, a reaction of immense technological relevance. Imaging has been performed in the feedback mode by allowing H(2) evolution at the tip (25 A mu m Pt UME), which is reoxidized at the substrate electrode containing Pt/C-Nafion film. Interesting distribution in H(2) oxidation activity has been observed as a function of potential applied to the Pt/C-Nafion film. In addition, a plot of normalized tip current versus the substrate electrode potential indicates the effect of potential-induced reactivity change in the catalyst-coated membranes. The results of the present investigation are believed to be useful to H(2)/O(2) PEM fuel cells with respect to evaluating reactivity gradients of catalyst-coated polymer electrolyte membranes, which is important to rectify problems related to catalyst utilization.</p>10ahydrogen oxidation10aImaging10aNafion10aplatinum10aSECM1 aParthasarathy, Meera1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/imaging-hydrogen-oxidation-activity-catalyst-coated-perfluoro-sulfonic-acid-polymer-002078nas a2200169   4500008004100000022001400041245018000055210006900235260007100304300001400375490000800389520130500397100002301702700002401725700003001749856012901779       2009                        eng d  a1932-744700aPreparation and characterization of rhodium nanostructures through the evolution of microgalvanic cells and their enhanced electrocatalytic activity for formaldehyde oxidation0 aPreparation and characterization of rhodium nanostructures throu  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN  a9616-96220 v1133 a<p>Shape-controlled morphological evolution of nanostructured Rh has been demonstrated with the help of a galvanic displacement reaction using Al in 1 mM aqueous Rh(III) chloride at an open circuit potential 0.99 V and at a temperature of 273 K (room temperature). Nanospheres composed of small nanoparticles of size around 2.9 +/- 0.4 nm having uniform distribution with a FCC pattern have been evolved during the course of the reaction. Electrochemical results coupled with structural and morphological characterization data from transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and cyclic voltammetry (CV) suggested the formation of Rh nanostructures. Considering the role of the potential of substrate Al and Rh and diffusion of reactant and product species toward and from the surface of the Al, we proposed the tentative mechanism for the formation of microgalvanic cell. Significantly, these: rhodium nanostructures exhibit enhanced electrocatalytic activity toward many fuel cell reactions as demonstrated by formaldehyde oxidation in 0.5 M NaOH. The present strategy is expected to be valid for preparing many other similar electrocatalysts (Pt, Au, and Pd) capable of exhibiting such a remarkable size- and shape-dependent reactivity.</p>1 aSathe, Bhaskar, R.1 aShinde, Dhanraj, B.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/preparation-and-characterization-rhodium-nanostructures-through-evolution-microgalvanic-002272nas a2200253   4500008004100000022001400041245007000055210006900125260009200194300001000286490000600296520136500302653002101667653003001688653004101718100002301759700001901782700002201801700001801823700002101841700003001862700002201892856010401914       2009                        eng d  a1947-293500aSynthesis of Sb-doped SnO2 nanowires and hyperbranched structures0 aSynthesis of Sbdoped SnO2 nanowires and hyperbranched structures  a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScAPR  a38-430 v13 a<p>Branched nanostructures of semiconducting materials are of great interest for their potential applications in optoelectronic, photonic devices and sensors. We herein describe a facile single-step chemical vapor deposition route for the synthesis of Sb-SnO2 hyperbranched nanostructures comprised of elongated nanowires with 30-40 nm diameter and 10-20 Am length. The morphology and structure has been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selective area electron diffraction (SAED), and powder X-ray diffraction (XRD). Also, a possible mechanism is proposed for the growth of nanowires into the hyperbranched form on the basis of the substrate effect, the role of Au nanoparticles, and the effect of Sb doping on specific morphology evolution. Interestingly, electrical conductivity measurements as a function of temperature suggest a semiconducting behavior, despite being governed by different electron-transport mechanisms with activation energies of 0.55 and 0.17 eV, which correspond to pure SnO2 and Sb-SnO2 nanowires, respectively. A precise control over the operating parameters not only envisages custom-designed, branched structures by a simple and economical route but also offers an alternative method to the expensive and tedious nanofabrication techniques for industrial applications.</p>10aAu Nanoparticles10achemical vapor deposition10aSb-SnO2 Hyperbranched Nanostructures1 aSathe, Bhaskar, R.1 aPatil, Mrudula1 aWalke, Pravin, S.1 aVivek, J., P.1 aLele, Ashish, K.1 aPillai, Vijayamohanan, K.1 aMulla, Imtiaz, S.  uhttps://library.ncl.res.in/content/synthesis-sb-doped-sno2-nanowires-and-hyperbranched-structures-001812nas a2200241   4500008004100000022001400041245013100055210006900186260009500255300001400350490000600364520087100370653003501241653001001276653002501286100001701311700001701328700002001345700002801365700003001393700001701423856013001440       2009                        eng d  a1533-488000aUltrafast switching time and third order nonlinear coefficients of microwave treated single walled carbon nanotube suspensions0 aUltrafast switching time and third order nonlinear coefficients   a25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USAbAMER SCIENTIFIC PUBLISHERScSEP  a5550-55540 v93 a<p>Microwave treated water soluble and amide functionalized single walled carbon nanotubes have been investigated using femtosecond degenerate pump-probe and nonlinear transmission experiments. The time resolved differential transmission using 75 femtosecond pulse with the central wavelength of 790 nm shows a bi-exponential ultrafast photo-bleaching with time constants of 160 fs (130 fs) and 920 fs (300 fs) for water soluble (amide functionalized) nanotubes. Open and closed aperture z-scans show saturation absorption and positive (negative) nonlinear refraction for water soluble (amide functionalized) nanotubes. Two photon absorption coefficient, beta(0) similar to 250 cm/GW (650 cm/GW) and nonlinear index, gamma similar to 15 cm(2)/pW (-30 cm(2)/pW) are obtained from the theoretical fit in the saturation limit to the data for two types of nanotubes.</p>10aNonlinear Optical Coefficients10aSWCNT10aUltra-Fast Switching1 aKamaraju, N.1 aKumar, Sunil1 aKarthikeyan, B.1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.1 aSood, A., K.  uhttps://library.ncl.res.in/content/ultrafast-switching-time-and-third-order-nonlinear-coefficients-microwave-treated-single-001991nas a2200253   4500008004100000022001400041245010500055210006900160260006900229300001000298490000800308520107500316653002101391653001501412653002801427653001801455653002801473653001601501100002501517700002101542700002001563700003001583856012401613       2009                        eng d  a1572-665700aY-junction nanostructures of palladium: enhanced electrocatalytic properties for fuel cell reactions0 aYjunction nanostructures of palladium enhanced electrocatalytic   aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR  a58-620 v6273 a<p>Here we demonstrate the utility of hierarchically designed alumina templates for the formation of palladium Y-junction nanostructures through a chemical vapor deposition route. These structures exhibit enhanced electrocatalytic activity for the oxidation of formic acid (up to 1020%) compared to that of platinum Y-junction nanostructures, which could be of immense relevance to portable fuel cell technology, since designing a better electrocatalyst for fuel cell reactions continues to be an important challenge. Apart from the obvious applications in fuel cell electrocatalysis, these Y-junction nanostructures could also act as promising candidates for room temperature hydrogen separation and more importantly as interconnects in molecular scale electronic devices. The present method of fabrication of Y-junction nanostructures using hierarchical alumina templates could be extended to other metallic/semiconducting systems facilitating more general opportunities for such hierarchical designs in nanoelectronics. (C) 2008 Elsevier B.V. All rights reserved.</p>10aelectrocatalysts10afuel cells10aHierarchical structures10aNanostructure10aPorous alumina membrane10aY-junctions1 aSubhramannia, Mahima1 aRamaiyan, Kannan1 aAslam, Mohammed1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/y-junction-nanostructures-palladium-enhanced-electrocatalytic-properties-fuel-cell-001894nas a2200205   4500008004100000022001400041245014500055210006900200260007100269300001400340490000600354520106200360100002101422700002201443700002901465700002401494700002201518700003001540856011801570       2010                        eng d  a1948-718500aArtificially designed membranes using phosphonated multiwall carbon nanotube-polybenzimidazole composites for polymer electrolyte fuel cells0 aArtificially designed membranes using phosphonated multiwall car  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL  a2109-21130 v13 a<p>The ability of phosphonated carbon nanotubes to offer an unprecedented approach to tune both proton-conductivity and mechanical stability of hybrid polymer electrolytes based on the polybenzimidazole membrane is demonstrated for fuel cell applications. The covalent attachment between the amino group of the 2-aminoethylphosphonic acid precursor and CNTs has been confirmed by NMR and IR experiments, while EDAX analysis indicates that one out of every 20 carbon atoms is in the CNT is functionalized. Proton conductivity of the composite membrane shows a remarkable 50% improvement in performance while a maximum power density of 780 and 600 mW cm(-2) is obtained for the composite and pristine membranes, respectively. Finally, the ultimate strength determined for the composite and pristine membranes is 100 and 65 MPa, respectively, demonstrating the superiority of the composite. This study opens up a new strategy to systematically tune the properties of polymer electrolytes for special applications by using appropriately functionalized CNTS.</p>1 aKannan, Ramaiyan1 aAher, Pradnya, P.1 aPalaniselvam, Thangavelu1 aKurungot, Sreekumar1 aKharul, Ulhas, K.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/artificially-designed-membranes-using-phosphonated-multiwall-carbon-nanotube-001595nas a2200181   4500008004100000022001400041245014400055210006900199260011000268300001400378490000700392520078800399100002501187700002101212700002401233700003001257856012601287       2010                        eng d  a0959-942800aBio-inspired catalyst compositions for enhanced oxygen reduction using nanostructured Pt electrocatalysts in polymer electrolyte fuel cells0 aBioinspired catalyst compositions for enhanced oxygen reduction   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a9651-96570 v203 a<p>Composites of Nafion with a class of bio-molecules viz., plant hormones, are explored as potential polymer electrolytes for improving the proton transport inside the catalyst layer of a H(2)/O(2) fuel cell. Specifically, four nitrogenous plant hormones, two each from the class of auxins and cytokinins have been investigated, following preliminary characterization of the composite dispersions and membranes. Interestingly, the use of indole-3-acetic acid (an auxin) in the catalyst layer reveals a 30% enhancement in Pt catalyst utilization and improved fuel cell performance by 150 mW cm(-2). The effect of these bio-molecules on the kinetic and mass transport parameters has been analyzed systematically using a combination of electrochemical and spectroscopic techniques.</p>1 aParthasarathy, Meera1 aKannan, Ramaiyan1 aSreekumar, Kurungot1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/bio-inspired-catalyst-compositions-enhanced-oxygen-reduction-using-nanostructured-pt-001411nas a2200181   4500008004100000022001400041245007600055210006900131260007300200300001200273490000800285520073500293100002301028700002201051700002201073700003001095856010401125       2010                        eng d  a0009-261400aEffect of Fe3O4 on morphology of Fe-SnO2 hyperbranched heterostructures0 aEffect of Fe3O4 on morphology of FeSnO2 hyperbranched heterostru  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a121-1250 v4933 a<p>A simple modified thermal evaporation technique is employed for the synthesis of microstructured Fe:SnO2 system and their plausible growth mechanism has been proposed based on the results from various characterization techniques. Such structures grow in two steps; initially, growth of Fe core takes place from Fe3O4 source which acts as nucleating site for SnO2 growth on its surface as per the vapor-liquid- solid progression. Moreover, the composition of Fe/Sn source and temperature are found to have key roles in governing their morphology. XPS studies clearly demonstrate the presence of Fe species, which acts as a catalyst along with source for hetero-structure growth with SnO2. (C) 2010 Published by Elsevier B.V.</p>1 aSathe, Bhaskar, R.1 aWalke, Pravin, S.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/effect-fe3o4-morphology-fe-sno2-hyperbranched-heterostructures-001688nas a2200289   4500008004100000022001400041245008700055210006900142260009200211300001800303490000600321520071700327653001801044653001101062653001101073653001901084653001401103653000901117100002101126700002401147700001401171700002301185700002201208700003001230700002001260856011801280       2010                        eng d  a1745-808000aFabrication of In-doped SnO2 nanowire arrays and its field emission investigations0 aFabrication of Indoped SnO2 nanowire arrays and its field emissi  a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcDEC  aPII 9312836630 v53 a<p>The field emission of In-doped SnO2 wire array has been performed in parallel plate diode configuration. A maximum current density of 60 mu A/cm2 is drawn from the emitter at an applied field of 4 V/mu m. The nonlinearity in the Fowler-Nordheim plot, characteristics of semiconductor emitter has been observed and explained on the basis of electron emission from both the conduction and the valence bands. The current stability recorded at a preset value of 1 mu A is observed to be good. The high emission current density, good current stability and mechanically robust nature of the wires offer unprecedented advantages as promising cold cathodes for many potential applications based on field emission.</p>10acold cathodes10adevice10aDoping10afield emission10aNanowires10aSnO21 aBhise, Ashok, B.1 aLate, Dattatray, J.1 aSathe, B.1 aMore, Mahendra, A.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.1 aJoag, Dilip, S.  uhttps://library.ncl.res.in/content/fabrication-doped-sno2-nanowire-arrays-and-its-field-emission-investigations-001602nas a2200253   4500008004100000022001400041245010500055210006900160260007100229300001400300490000600314520069700320653001901017653002501036653001901061653001701080653000801097100002601105700002301131700002001154700002201174700003001196856012201226       2010                        eng d  a1936-085100aFowler-nordheim plot behavior and mechanism of field electron emission from ZnO tetrapod structures	0 aFowlernordheim plot behavior and mechanism of field electron emi  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a5585-55900 v43 a<p>Field emission measurements of current-voltage characteristics are reported for tetrapod structures of ZnO. The nonlinear Fowler-Nordheim (FN) plot is analyzed according to a model of calculation based on saturation of conduction band current and predominance of valence band current at high-field values. The simulated FN plot exhibits similar features to those observed experimentally. The model of calculation suggests that the slope variation of the FN plot, in the high-field and low-field regions, does not depend on the magnitude of saturation. Instead, it is a characteristic of the energy band structure and voltage-to-barrier-field conversion factor of the emitting material.</p>10afield emission10aFowler-Nordheim plot10aNanostructures10anonlinearity10aZnO1 aAl-Tabbakh, Ahmed, A.1 aMore, Mahendra, A.1 aJoag, Dilip, S.1 aMulla, Imtiaz, S.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/fowler-nordheim-plot-behavior-and-mechanism-field-electron-emission-zno-tetrapod-001211nas a2200205   4500008004100000022001400041245013700055210006900192260011000261300001400371490000700385520034200392100002100734700002200755700002200777700002500799700003000824700002400854856012700878       2010                        eng d  a1359-734500aHigh aspect ratio nanoscale multifunctional materials derived from hollow carbon nanofiber by polymer insertion and metal decoration0 aHigh aspect ratio nanoscale multifunctional materials derived fr  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN  a5590-55920 v463 a<p>A novel high aspect ratio material which can simultaneously display multiple functions such as proton and electron conductivity and electrocatalytic activity has been developed by incorporating both platinum nanoparticles and phosphoric acid doped polybenzimidazole along the inner and outer surfaces of a hollow carbon nanofiber.</p>1 aBalan, Beena, K.1 aKale, Vinayak, S.1 aAher, Pradnya, P.1 aShelke, Manjusha, V.1 aPillai, Vijayamohanan, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/high-aspect-ratio-nanoscale-multifunctional-materials-derived-hollow-carbon-nanofiber-001822nas a2200265   4500008004100000022001400041245010300055210006900158260012500227300001100352490000700363520081100370653002101181653002001202653001901222653001501241100002801256700003001284700002401314700002501338700002201363700002301385700002001408856012801428       2010                        eng d  a0003-695100aHigh current density, low threshold field emission from functionalized carbon nanotube bucky paper0 aHigh current density low threshold field emission from functiona  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAUG  a0731020 v973 a<p>Field emission studies of bucky paper of multiwalled carbon nanotubes (MWNTs), prepared after microwave (MW) assisted acid functionalization are reported along with a comparison with that of ``as-grown'' sample. MW treated bucky papers reveal an interesting linear field emission behavior in Fowler-Nordheim plot. The field emission currents at preset value are found to be remarkably stable over a period of more than 3 h sustaining current densities of 4.9 mA/cm(2) and 8.5 mA/cm(2) for ``as-grown'' and functionalized sample, respectively. The enhancement in the field emission due to functionalization has been discussed in terms of tip opening and defect induced charge transport caused by intershell and intertubular interaction. (C) 2010 American Institute of Physics. [doi:10.1063/1.3479049]</p>10aCarbon nanotubes10acurrent density10afield emission10afullerenes1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.1 aLate, Dattatray, J.1 aChavan, Padmakar, G.1 aSheini, Farid, J.1 aMore, Mahendra, A.1 aJoag, Dilip, S.  uhttps://library.ncl.res.in/content/high-current-density-low-threshold-field-emission-functionalized-carbon-nanotube-bucky-003220nas a2200181   4500008004100000022001400041245018200055210006900237260007100306300001600377490000800393520240800401100002502809700002402834700003002858700002402888856012602912       2010                        eng d  a1932-744700aHigh pt utilization electrodes for polymer electrolyte membrane fuel cells by dispersing pt particles formed by a preprecipitation method on carbon ``polished'' with polypyrrole0 aHigh pt utilization electrodes for polymer electrolyte membrane   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a14654-146610 v1143 a<p>Pt utilization on carbon black (CB) has been significantly improved by initially utilizing polypyrrole (PPy) as a moiety to ``polish'' the carbon surface and subsequently by dispersing Pt particles formed by a preprecipitation process to minimize their migration into the geometrically restricted areas of the carbon surface. This process strategy has helped to significantly extend the triple-phase boundary as a greater number of Pt particles comes in direct contact with Nafion, leading to a substantial improvement in the overall catalyst utilization. Preliminary analyses such as IR, thermogravimetric analysis, and N(2) sorption confirmed the presence of PPy on the surface. Approximately 50% reduction in the surface area of CB after the controlled in situ polymerization of pyrrole monomer on the carbon surface indicated preferential filling and coverage of pores and other geometrically restricted pockets of carbon surface. On the other hand, by converting Pt into colloids in the preprecipitation method prior to their reduction, the platinum particles are forced to stay on the hybrid support; a major part of which otherwise would have been migrated into the surface pores and defect sites. Platinum particle size on these hybrid supports is 2 times higher than the catalyst prepared by polyol process. However, the electroactive surface area and mass activity are 2 times higher than that of the Pt particles prepared by polyol on hybrid material and are also significantly higher than that of the conventional electrocatalysts prepared by the polyol method. At 0.8 V, the kinetic current density (j(k)) of Pt/C-PPy-Pre obtained from the Koutecky-Levich plot is 1.5 and 2.5 times higher than that of catalysts prepared by the polyol method on PPy-coated carbon and Vulcan XC-72 carbon, respectively. Almost 210 and 160 mW cm(-2) improvement for the maximum power density, respectively with oxygen and air, was obtained with the modified system in comparison to the conventional system when the single cell evaluations were carried out at 60 degrees C with a Pt loading of 0.5 mg cm(-2) in the anode and cathode sides. This enhancement in the cell performance under the two different oxygen partial pressure conditions clearly emphasizes the improved oxygen reduction reaction (ORR) and mass-transfer characteristics of the hybrid electrode material compared to the other catalysts.</p>1 aUnni, SreeKuttan, M.1 aDhavale, Vishal, M.1 aPillai, Vijayamohanan, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/high-pt-utilization-electrodes-polymer-electrolyte-membrane-fuel-cells-dispersing-pt-001210nas a2200193   4500008004100000022001400041245010900055210006900164260011000233300001400343490000700357520040500364100002300769700002800792700001900820700002000839700003000859856012700889       2010                        eng d  a1359-734500aSynthesis of Rh-carbon nanotube based heterostructures and their enhanced field emission characteristics0 aSynthesis of Rhcarbon nanotube based heterostructures and their   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL  a5671-56730 v463 a<p>Selective decoration of Rh nanospheres on acid functionalized carbon nanotubes has been demonstrated using Al as a sacrificial substrate. Remarkable field emission has been observed for this heterostructure as a high current density of 170 mu A cm(-2) is generated at an ultra-low threshold of 300 V mu m(-1), compared to much smaller values for Rh nanospheres and carbon nanotubes separately.</p>1 aSathe, Bhaskar, R.1 aKakade, Bhalchandra, A.1 aKushwaha, Ajay1 aAslam, Mohammed1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/synthesis-rh-carbon-nanotube-based-heterostructures-and-their-enhanced-field-emission-002255nas a2200265   4500008004100000022001400041245013400055210006900189260009500258300001200353490000800365520121200373653002101585653002401606653003501630653001901665653002301684100002501707700002401732700002801756700002501784700002601809700003001835856012401865       2011                        eng d  a0003-269700aCarbon nanotube-modified sodium dodecyl sulfate-polyacrylamide gel electrophoresis for molecular weight determination of proteins0 aCarbon nanotubemodified sodium dodecyl sulfatepolyacrylamide gel  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcFEB  a230-2350 v4093 a<p>The effect of incorporating carbon nanotubes (CNTs) in the gel matrix on the electrophoretic mobility of proteins based on their molecular weight differences was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). More specifically, a reduction in standard deviation in the molecular weight calibration plots by 55% in the case of multiwalled carbon nanotubes (MWCNTs) and by 34% in the case of single-walled carbon nanotubes (SWCNTs) compared with that of pristine polyacrylamide gels was achieved after incorporating an insignificant amount of functionalized CNTs into the gel matrix. A mechanism based on a more uniform pore size distribution in CNT modified polyacrylamide gel matrix is proposed. Furthermore, the impact of SWCNTs and MWCNTs on the mobility of proteins in different molecular weight regimes at a given acrylamide concentration offers a tunable gel matrix in terms of the selection of molecular weight ranges of proteins. The robustness and excellent reproducibility of the CNT-PAGE protocol are expected to have a significant impact on the molecular weight determination of newly isolated proteins. (C) 2010 Elsevier Inc. All rights reserved.</p>10aCarbon nanotubes10aGel electrophoresis10aMolecular weight determination10aPolyacrylamide10aProtein separation1 aParthasarathy, Meera1 aDebgupta, Joyashish1 aKakade, Bhalchandra, A.1 aAnsary, Abu, Ayoobul1 aKhan, Mohammad, Islam1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/carbon-nanotube-modified-sodium-dodecyl-sulfate-polyacrylamide-gel-electrophoresis-001841nas a2200169   4500008004100000022001400041245013400055210006900189260011000258300001600368490000700384520107200391100002401463700002801487700003001515856012601545       2011                        eng d  a1463-907600aCompetitive wetting of acetonitrile and dichloromethane in comparison to that of water on functionalized carbon nanotube surfaces0 aCompetitive wetting of acetonitrile and dichloromethane in compa  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL  a14668-146740 v133 a<p>Differential wetting of pristine and ozonized carbon nanotubes has been studied using solvents like acetonitrile and dichloromethane in comparison to the well-known wetting behavior of water. Based on their unique structural and physical properties, functionalized CNT substrates have been used due to the fact that independent variation in molecular as well as electronic properties could be controlled by understanding the wetting of these liquids on carbon nanotubes (CNTs), both pristine as well as ozone treated. The sensitivity of the wetting behavior with respect to molecular interactions has been investigated using contact angle measurements while Raman and XPS studies unravel the differential wetting behavior. Charge-transfer between adsorbed molecules and CNTs has been identified to play a crucial role in determining the interfacial energies of these two liquids, especially in the case of acetonitrile. Ozone treatment has been observed to affect the surface properties of pristine CNTs along with a concomitant change in the wetting dynamics.</p>1 aDebgupta, Joyashish1 aKakade, Bhalchandra, A.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/competitive-wetting-acetonitrile-and-dichloromethane-comparison-water-functionalized-001530nas a2200193   4500008004100000022001400041245012100055210006900176260007100245300001400316490000800330520075400338100002401092700002401116700001901140700002001159700003001179856012701209       2011                        eng d  a0002-786300aElectrochemical unzipping of multi-walled carbon nanotubes for facile synthesis of high-quality graphene nanoribbons0 aElectrochemical unzipping of multiwalled carbon nanotubes for fa  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a4168-41710 v1333 a<p>Here we report a remarkable transformation of carbon nanotubes (CNTs) to nanoribbons composed of a few layers of graphene by a two-step electrochemical approach. This consists of the oxidation of CNTs at controlled potential, followed by reduction to form graphene nanoribbons (GNRs) having smooth edges and fewer defects, as evidenced by multiple characterization techniques, including Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. This type of ``unzipping'' of CNTs (single-walled, multi-walled) in the presence of an interfacial electric field provides unique advantages with respect to the orientation of CNTs, which might make possible the production of GNRs with controlled widths and fewer defects.</p>1 aShinde, Dhanraj, B.1 aDebgupta, Joyashish1 aKushwaha, Ajay1 aAslam, Mohammed1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/electrochemical-unzipping-multi-walled-carbon-nanotubes-facile-synthesis-high-quality-002146nas a2200181   4500008004100000022001400041245014700055210006900202260011000271300001600381490000700397520133800404100002101742700001901763700002401782700003001806856012801836       2011                        eng d  a1463-907600aEnhanced electrocatalytic performance of functionalized carbon nanotube electrodes for oxygen reduction in proton exchange membrane fuel cells0 aEnhanced electrocatalytic performance of functionalized carbon n  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR  a10312-103170 v133 a<p>Although nitrogen doped CNTs (N-CNTs) are considered as a promising alternative to platinized carbon for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs), the origin of the enhanced ORR activity with N-CNTs is not clear at present. Among several plausible reasons, the exposure of edge plane and creation of impurity band/surface states near the Fermi level are considered as major causes behind the catalytic activity. However, CNTs without nitrogen doping are not known to catalyze the ORR. In this work, we study the ORR activity of functionalized carbon nanotubes with different functional groups, such as sulfonic acid and phosphonic acid, in order to understand the role of surface functionalities in catalyzing the reaction. Functionalized CNTs show significantly enhanced activity towards the ORR, while CNTs without such surface functional groups do not reveal any such special ORR activity. Linear sweep voltammetry experiments with different rotation rates show diffusion controlled limiting current values for functionalized CNTs, and the `n' values derived from Koutecky-Levich plots are 3.3 and 1.7 for S-MWCNTs and P-MWCNTs, respectively. This work demonstrates the ORR activity of functionalized MWCNTs, which opens up new strategies for electrocatalyst design in PEMFCs.</p>1 aKannan, Ramaiyan1 aBipinlal, Unni1 aKurungot, Sreekumar1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/enhanced-electrocatalytic-performance-functionalized-carbon-nanotube-electrodes-oxygen-002211nas a2200169   4500008004100000022001400041245010500055210006900160260011000229300001400339490000600353520147900359100002301838700002101861700003001882856012901912       2011                        eng d  a1754-569200aEnhanced electrocatalytic performance of interconnected Rh nano-chains towards formic acid oxidation0 aEnhanced electrocatalytic performance of interconnected Rh nanoc  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a1029-10360 v43 a<p>A chain-like assembly of rhodium nanoparticles (5-7 nm mean diameter) has been synthesized from rhodium chloride with the help of polydentate molecules like tartaric and ascorbic acids (1 : 3 in mM scale) as capping agents at room temperature. Subsequent characterization using transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy reveals a unique inter-connected network like features, while their electrochemical behavior using cyclic voltammetry and current-time transient suggests potential applications as electrocatalysts in fuel cells. A significant negative shift in the onset potential as well as higher anodic peak current density for formic acid oxidation on Rh-tartaric acid (Rh-TA) as compared to that of bulk Rh metal confirms their higher electrocatalytic activity. Interestingly, the enhancement factor (R) with respect to that of bulk metallic Rh towards formic acid oxidation ranges up to 2000% for Rh-TA and 1200% for Rh-AA (Rh-ascorbic acid) respectively. The composition of Rh nano-chains has been further analyzed with thermogravimetry and Fourier transform infra-red spectroscopy to demonstrate the importance of controlling the chain topology using polyfunctional organic molecules. These findings open up new possibilities for tailoring nanostructured electrodes with potential benefits since the development of a better electrocatalysts for many fuel cell reactions continues to be an important challenge.</p>1 aSathe, Bhaskar, R.1 aBalan, Beena, K.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/enhanced-electrocatalytic-performance-interconnected-rh-nano-chains-towards-formic-acid-001098nas a2200193   4500008004100000022001400041245014500055210006900200260011000269300001400379490000700393520024500400100002400645700002500669700002600694700003000720700002400750856013000774       2011                        eng d  a1359-734500aEx-situ dispersion of core-shell nanoparticles of Cu-Pt on an in situ modified carbon surface and their enhanced electrocatalytic activities0 aExsitu dispersion of coreshell nanoparticles of CuPt on an in si  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a3951-39530 v473 a<p>Direct dispersion of core-shell nanoparticles on a carbon support (Cu@ Pt/C) has been achieved while retaining the essential core-shell features of the nanoparticles by adopting an in situ surface modification-cum-anchoring strategy.</p>1 aDhavale, Vishal, M.1 aUnni, SreeKuttan, M.1 aKagalwala, Husain, N.1 aPillai, Vijayamohanan, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/ex-situ-dispersion-core-shell-nanoparticles-cu-pt-situ-modified-carbon-surface-and-their-001933nas a2200193   4500008004100000022001400041245010500055210006900160260007100229300001600300490000800316520117500324100001901499700002001518700002301538700003001561700002201591856012601613       2011                        eng d  a1932-744700aFunctionalization of SBA-15 mesoporous materials using ``thiol-ene click'' michael addition reaction0 aFunctionalization of SBA15 mesoporous materials using thiolene c  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a17774-177810 v1153 a<p>Methacrylate-labeled SBA-15 has been successfully synthesized from calcined SBA-15 and commercially available 3-trichlorosilyl propylmethacrylate. This material undergoes efficient thiol-ene ``click reaction'' with a variety of both thiol and disulfide-containing substrates in aqueous and organic media. The products were thoroughly characterized by a variety of analytical techniques including multinuclear (C-13, Si-29) solid-state NMR, TG-DTA, and nitrogen adsorption desorption studies. Disulfide-containing substrates in which the TCEP-mediated reduction of the disulfide bond and its subsequent addition to the methacrylate group anchored in SBA-15 in one-pot were used to synthesize a silica-protein hybrid material composed of biotin-labeled SBA-15 and streptavidin. Electrochemically active material was synthesized from the reaction of ferrocene-containing thiol and the methacrylate-labeled SBA-15. The ease of synthesis for the methacrylate-labeled SBA-15 material together with its ability to undergo efficient chemoselective thiol-ene reaction would make it a very attractive platform for the development of covalently anchored enzymes and sensors.</p>1 aKumari, Sushma1 aMalvi, Bharmana1 aGanai, Anal, Kumar1 aPillai, Vijayamohanan, K.1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/functionalization-sba-15-mesoporous-materials-using-thiol-ene-click-michael-addition-002675nas a2200205   4500008004100000022001400041245013400055210006900189260011000258300001400368490000700382520180100389100002102190700002602211700002702237700002202264700002402286700003002310856012902340       2011                        eng d  a0959-942800aImproved performance of phosphonated carbon nanotube-polybenzimidazole composite membranes in proton exchange membrane fuel cells0 aImproved performance of phosphonated carbon nanotubepolybenzimid  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR  a7223-72310 v213 a<p>Development of thermally stable polymer electrolyte membranes with higher proton conductivity as well as mechanical stability is a key challenge in commercializing PEM fuel cells operating above 100 degrees C. Polybenzimidazole membranes are one of the promising candidates in this category although with limited mechanical stability and moderate proton conductivity. Here the incorporation of functionalized MWCNT is shown to increase both these key parameters of the polybenzimidazole membranes. Further, formation of a domain like structure after the incorporation of phosphonated MWCNTs (P-MWCNTs) in phosphoric acid doped polybenzimidazole membranes is demonstrated. The enhanced performance has been attributed to the formation of proton conducting networks that formed along the sidewalls of P-MWCNTs with a domain size of 17 nm as estimated from the small angle X-ray scattering measurements. Membrane electrode assembly (MEA) impedance measurements further reveal that the activation energy of oxygen reduction reaction (ORR) reduced for the composite membranes with enhanced proton conductivity. In addition, the mechanical strength measurements reveal a significant improvement in the yield strength and ultimate strength. Also, the mechanical strength of the composite membrane has been increased significantly as indicated by the improvement in the ultimate strength from 65 MPa to 100 MPa for the pristine and composite membranes, respectively. The optimum loading of P-MWCNTs is found to be 1% as inferred from the polarization measurements carried out using pure hydrogen and oxygen. Thus, this study provides a unique opportunity to tune the properties of polymer electrolytes to prepare application oriented hybrid membranes using CNTs with tailor-made functional groups.</p>1 aKannan, Ramaiyan1 aKagalwala, Husain, N.1 aChaudhari, Harshal, D.1 aKharul, Ulhas, K.1 aKurungot, Sreekumar1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/improved-performance-phosphonated-carbon-nanotube-polybenzimidazole-composite-membranes-001777nas a2200181   4500008004100000022001400041245008300055210006900138260012500207300001100332490000800343520103000351100002901381700002101410700003001431700001701461856011701478       2012                        eng d  a0021-897900aCharge transport in functionalized multi-wall carbon nanotube-Nafion composite0 aCharge transport in functionalized multiwall carbon nanotubeNafi  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScSEP  a0537060 v1123 a<p>The charge transport in sulfonated multi-wall carbon nanotube (sMWNT)-Nafion composite is reported. The scanning electron microscope images of the composite, at 1 and 10 wt % of sMWNT, show that the nanotubes are well dispersed in polymer matrix, with conductivity values of 0.005 and 3.2 S/cm, respectively; and the percolation threshold is nearly 0.42 wt. %. The exponent (similar to 0.25) of the temperature dependence of conductivity in both samples indicates Mott's variable range hopping (VRH) transport. The conductance in 1 wt. % sample increases by three orders of magnitude at high electric-fields, consistent with VRH model. The negative magnetoresistance in 10 wt. % sample is attributed to the forward interference scattering mechanism in VRH transport. The ac conductance in 1 wt. % sample is expressed by sigma(omega) proportional to omega(s), and the temperature dependence of s follows the correlated barrier hopping model. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4749264]</p>1 aSangeeth, C., S. Suchand1 aKannan, Ramaiyan1 aPillai, Vijayamohanan, K.1 aMenon, Reghu  uhttps://library.ncl.res.in/content/charge-transport-functionalized-multi-wall-carbon-nanotube-nafion-composite-001962nas a2200217   4500008004100000022001400041245010300055210006900158260007500227300001600302490000700318520113200325653003001457653001301487653001901500653002201519653001701541100002401558700003001582856013201612       2012                        eng d  a0947-653900aElectrochemical preparation of luminescent graphene quantum dots from multiwalled carbon nanotubes0 aElectrochemical preparation of luminescent graphene quantum dots  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcSEP  a12522-125280 v183 a<p>Green luminescent, graphene quantum dots (GQDs) with a uniform size of 3, 5, and 8.2(+/- 0.3) nm in diameter were prepared electrochemically from MWCNTs in propylene carbonate by using LiClO4 at 90?degrees C, whereas similar particles of 23(+/- 2) nm were obtained at 30?degrees C under identical conditions. Both these sets of GQDs displayed a remarkable quantum efficiency of 6.3 and 5.1?%, respectively. This method offers a novel strategy to synthesise size-tunable GQDs as evidenced by multiple characterisation techniques like transmission and scanning electron microscopy, atomic force microscopy, Raman spectroscopy and X-ray diffraction (XRD). Photoluminescence of these GQDs can be tailored by size variation through a systematic change in key process parameters, like diameter of carbon nanotube, electric field, concentration of supporting electrolyte and temperature. GQDs are promising candidates for a variety of applications, such as biomarkers, nanoelectronic devices and chemosensors due to their unique features, like high photostability, biocompatibility, nontoxicity and tunable solubility in water.</p>10aelectrochemical synthesis10agraphene10aNanostructures10aphotoluminescence10aquantum dots1 aShinde, Dhanraj, B.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/electrochemical-preparation-luminescent-graphene-quantum-dots-multiwalled-carbon-nanotubes-002041nas a2200169   4500008004100000022001400041245012400055210006900179260011000248300001200358490000600370520129000376100002401666700003001690700002401720856012701744       2012                        eng d  a2040-336400aHydrous RuO2-carbon nanofiber electrodes with high mass and electrode-specific capacitance for efficient energy storage0 aHydrous RuO2carbon nanofiber electrodes with high mass and elect  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a890-8960 v43 a<p>We demonstrate a new strategy for the fabrication of supercapacitor electrodes possessing high mass and area-specific capacitance for efficient charge storage, which can be extremely useful for the development of light, compact and high performance supercapacitors for a variety of high power demanding applications. High mass and electrode area specific capacitances were attained by using Hydrous Ruthenium Oxide (HRO)-Carbon Nanofiber (CNF) hybrid electrodes prepared by the deposition of HRO (similar to 31% Ru content) on both the outer and inner surfaces of a cylindrical hollow CNF having open tips. Electrochemical studies of the uniformly deposited HRO nanoparticles on the CNF surface showed a mass specific capacitance of 645 F g(-1) and an electrode specific capacitance of 1.29 F cm(-2) with a HRO-CNF material loading of 2 mg cm(-2) in the supercapacitor electrodes. The mass specific capacitance of pure HRO is 301 F g(-1), whereas the mass specific capacitance of HRO in the HRO-CNF electrode is similar to 1300 F g(-1), which is very close to the theoretical capacitance of HRO. This enhanced charge storage ability, high rate capability, better cyclic stability and low ESR of the HRO-CNF will be useful for the development of high performance supercapacitors.</p>1 aVellacheri, Ranjith1 aPillai, Vijayamohanan, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/hydrous-ruo2-carbon-nanofiber-electrodes-high-mass-and-electrode-specific-capacitance-001109nas a2200169   4500008004100000022001400041245011100055210006900166260011000235300001400345490000700359520036900366100002400735700002400759700003000783856012600813       2012                        eng d  a1359-734500aIn situ electrochemical organization of CdSe nanoclusters on graphene during unzipping of carbon nanotubes0 aIn situ electrochemical organization of CdSe nanoclusters on gra  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a3088-30900 v483 a<p>In situ decoration of very small CdSe quantum dots on graphene nanoribbons (GNRs) has been achieved during the electrochemical unzipping of single walled carbon nanotubes. Critical parameters like the width of the GNRs, size distribution of quantum dots and their organization on GNRs have been shown to be strongly dependent on the electric field and time.</p>1 aDebgupta, Joyashish1 aShinde, Dhanraj, B.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/situ-electrochemical-organization-cdse-nanoclusters-graphene-during-unzipping-carbon-002443nas a2200169   4500008004100000022001400041245014900055210006900204260011000273300001400383490000600397520166600403100002502069700003002094700002402124856012502148       2013                        eng d  a2046-206900a3-Dimensionally self-assembled single crystalline platinum nanostructures on few-layer graphene as an efficient oxygen reduction electrocatalyst0 a3Dimensionally selfassembled single crystalline platinum nanostr  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a6913-69210 v33 a<p>Here, we report for the first time the synthesis of a 3-D self-assembled single crystalline platinum nanostructure directly on the graphene surface (PtNAGE) without using any harmful structural directing agents. A slow reduction method is used to prepare the desired platinum morphology. Initial formation of platinum nanoparticles and their homogenous dispersion on the surface of graphene have been observed 10 h after the commencement of the reduction using formic acid as the reducing agent. From these initially deposited seed particles, the growth starts on the {111} facets along the &lt; 111 &gt; direction and the nanostructure formation is completed within 72 h of the commencement of the reaction. The individual assembly has a diameter of similar to 80 nm. PtNAGE shows superior electrocatalytic activity towards oxygen reduction compared to graphene supported platinum (PtGE) and commercial carbon supported platinum (PtC) catalysts. PtNAGE is less vulnerable to strong hydroxyl adsorption compared to PtC and PtGE. Specific activity and mass activity of the catalyst are high compared to PtC by a factor of 6.50 and 1.80, respectively, and 4.00 and 3.05, respectively, compared to PtGE. The limiting current density of PtNAGE is 1.28 and 1.20 times higher than PtGE and PtC, respectively. Kinetic analysis of PtNAGE shows that the oxygen reduction reaction follows first order kinetics involving a four electron transfer mechanism with the direct formation of water. In addition to this, it has been observed that PtNAGE also prevents surface area degradation better than the commercial platinised carbon under potential induced conditions.</p>1 aUnni, SreeKuttan, M.1 aPillai, Vijayamohanan, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/3-dimensionally-self-assembled-single-crystalline-platinum-nanostructures-few-layer-000790nas a2200205   4500008004100000022001400041245008200055210006900137260007700206300001400283490000700297653002000304653003500324653001300359653001700372653002900389100002400418700003000442856011200472       2013                        eng d  a1433-785100aElectrochemical resolution of multiple redox events for graphene quantum dots0 aElectrochemical resolution of multiple redox events for graphene  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJAN  a2482-24850 v5210acharging energy10adifferential pulse voltammetry10agraphene10aquantum dots10asingle-electron transfer1 aShinde, Dhanraj, B.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/electrochemical-resolution-multiple-redox-events-graphene-quantum-dots-001416nas a2200193   4500008004100000022001400041245006000055210006000115260012500175300001100300490000800311520069900319100001801018700002001036700002401056700003001080700002001110856009201130       2013                        eng d  a0003-695100aHysteresis and charge trapping in graphene quantum dots0 aHysteresis and charge trapping in graphene quantum dots  aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAPR  a1431040 v1023 a<p>We report current hysteresis in response to applied voltage in graphene quantum dots of average diameter 4.5 +/- 0.55 nm, synthesized electrochemically using multiwalled carbon nanotubes. In response to step voltages, transient current decay, characteristic of deep and shallow level charge traps with time constants 186 ms and 6 s, is observed. Discharging current transients indicate charge storage of the order of 100 mu C. Trap states are believed to arise due to the fast physisorption of external adsorbates, which are found to have a significant effect on charge transport and changes the resistance of the prepared device by an order of 3. (C) 2013 American Institute of Physics.</p>1 aKalita, Hemen1 aHarikrishnan, V1 aShinde, Dhanraj, B.1 aPillai, Vijayamohanan, K.1 aAslam, Mohammed  uhttps://library.ncl.res.in/content/hysteresis-and-charge-trapping-graphene-quantum-dots01497nas a2200181   4500008004100000022001400041245014700055210006900202260011000271300001600381490000600397520069100403100002301094700002401117700003001141700002001171856012401191       2013                        eng d  a2040-336400aStabilization of graphene quantum dots (GQDs) by encapsulation inside zeolitic imidazolate framework nanocrystals for photoluminescence tuning0 aStabilization of graphene quantum dots GQDs by encapsulation ins  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a10556-105610 v53 a<p>Luminescent graphene quantum dots (GQDs) are encapsulated and stabilized in Zeolitic Imidazolate Framework (ZIF-8) nanocrystals. The GQDs are well confined due to the adsorption on the growing face of the ZIF-8 nanocrystals and have a profound effect on the shape of the nanocrystals from rhombic dodecahedron to spherical. Stabilizing GQDs inside the ZIF-8 nanocrystals results in tailoring of the photoluminescence emission (ca. 32 nm, bathochromic shift) of the GQD@ZIF-8 nanocrystal composite even after 3 months of aging under normal laboratory conditions. Also the water adsorption (at STP) capacity increased for the GQD@ ZIF-8 composite as compared to the pristine ZIF-8.</p>1 aBiswal, Bishnu, P.1 aShinde, Dhanraj, B.1 aPillai, Vijayamohanan, K.1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/stabilization-graphene-quantum-dots-gqds-encapsulation-inside-zeolitic-imidazolate-002065nas a2200229   4500008004100000022001400041245014900055210006900204260010200273300001000375490000800385520110500393653002001498653002401518653005901542100002001601700003001621700001501651700001601666700002101682856013201703       2013                        eng d  a0974-362600aStructural and catalytic properties of a novel vanadium containing solid core mesoporous silica shell catalysts for gas phase oxidation reaction0 aStructural and catalytic properties of a novel vanadium containi  aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScJAN  a63-690 v1253 a<p>A novel vanadium containing solid core mesoporous silica shell catalyst was synthesized with different Si/V ratios by sol-gel method under neutral conditions. The synthesized materials were characterized by various techniques and gas phase diphenyl methane oxidation reaction. The mesoporosity combined with microporosity are formed by incorporation of octadecyltrichloro silane and triethylamine in the catalyst and it was found out from E-DAX and BET-surface area analysis. The material was found to be nanocrystalline. Vanadium is present as V4 + species in as-synthesized samples and convert to V5 + on calcination. Most of the vanadium is present in tetrahedral or square pyramidal environment. Incorporation of vanadium in silica framework was confirmed by Si-29 MAS NMR analysis. Among the various vanadium containing solid core mesoporous silica shell catalysts, the Si/V = 100 ratio exhibited maximum efficiency towards diphenyl methane to benzophenone gas phase reaction. The optimum condition required for maximum conversion and selectivity was found out from the catalytic studies.</p>10adiphenylmethane10aGas phase oxidation10avanadium containing solid core mesoporous silica shell1 aVenkatathri, N.1 aPillai, Vijayamohanan, K.1 aRajini, A.1 aRaju, Nooka1 aReddy, I., A. K.  uhttps://library.ncl.res.in/content/structural-and-catalytic-properties-novel-vanadium-containing-solid-core-mesoporous-silica-001025nas a2200157   4500008004100000022001400041245010000055210006900155260011000224300001400334490000600348520033400354100002400688700003000712856012500742       2013                        eng d  a2040-336400aThiolated graphene - a new platform for anchoring CdSe quantum dots for hybrid heterostructures0 aThiolated graphene a new platform for anchoring CdSe quantum dot  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a3615-36190 v53 a<p>Effective organization of small CdSe quantum dots on graphene sheets has been achieved by a simple solution exchange with thiol terminated graphene prepared by diazonium salt chemistry. This generic methodology of CdSe QD attachment to any graphene surface has remarkable implications in designing hybrid heterostructures.</p>1 aDebgupta, Joyashish1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/thiolated-graphene-new-platform-anchoring-cdse-quantum-dots-hybrid-heterostructures-001741nas a2200169   4500008004100000022001400041245014100055210006900196260009000265300002300355490000600378520098900384100002401373700002101397700003001418856012301448       2014                        eng d  a2045-232200aCounter-ion dependent, longitudinal unzipping of multi-walled carbon nanotubes to highly conductive and transparent graphene nanoribbons0 aCounterion dependent longitudinal unzipping of multiwalled carbo  aMACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLANDbNATURE PUBLISHING GROUPcMAR  aArticle No. : 43630 v43 a<p>Here we report for the first time, a simple hydrothermal approach for the bulk production of highly conductive and transparent graphene nanoribbons (GNRs) using several counter ions from K2SO4, KNO3, KOH and H2SO4 in aqueous media, where, selective intercalation followed by exfoliation gives highly conducting GNRs with over 80% yield. In these experiments, sulfate and nitrate ions act as a co-intercalant along with potassium ions resulting into exfoliation of multi-walled carbon nanotubes (MWCNTs) in an effective manner. The striking similarity of experimental results in KOH and H2SO4 that demonstrates partially damaged MWCNTs, implies that no individual K+, SO42- ion plays a key role in unwrapping of MWCNTs, rather this process is largely effective in the presence of both cations and anions working in a cooperative manner. The GNRs can be used for preparing conductive 16 k Omega sq(-1), transparent (82%) and flexible thin films using low cost fabrication method.</p>1 aShinde, Dhanraj, B.1 aMajumder, Mainak1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/counter-ion-dependent-longitudinal-unzipping-multi-walled-carbon-nanotubes-highly-001861nas a2200181   4500008004100000022001400041245013300055210006900188260009000257300000900347490000600356520108400362100002901446700002401475700003001499700002501529856012501554       2014                        eng d  a2045-232200aC@SiNW/TiO2 core-shell nanoarrays with sandwiched carbon passivation layer as high efficiency photoelectrode for water splitting0 aCSiNWTiO2 coreshell nanoarrays with sandwiched carbon passivatio  aMACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLANDbNATURE PUBLISHING GROUPcMAY  a48970 v43 a<p>One-dimensional heterostructure nanoarrays are efficiently promising as high performance electrodes for photo electrochemical (PEC) water splitting applications, wherein it is highly desirable for the electrode to have a broad light absorption, efficient charge separation and redox properties as well as defect free surface with high area suitable for fast interfacial charge transfer. We present highly active and unique photoelectrode for solar H-2 production, consisting of silicon nanowires (SiNWs)/TiO2 core-shell structures. SiNWs are passivated to reduce defect sites and protected against oxidation in air or water by forming very thin carbon layer sandwiched between SiNW and TiO2 surfaces. This carbon layer decreases recombination rates and also enhances the interfacial charge transfer between the silicon and TiO2. A systematic investigation of the role of SiNW length and TiO2 thickness on photocurrent reveals enhanced photocurrent density up to 5.97 mA/cm(2) at 1.0 V vs. NHE by using C@SiNW/TiO2 nanoarrays with photo electrochemical efficiency of 1.17%.</p>1 aDevarapalli, Rami, Reddy1 aDebgupta, Joyashish1 aPillai, Vijayamohanan, K.1 aShelke, Manjusha, V.  uhttps://library.ncl.res.in/content/csinwtio2-core-shell-nanoarrays-sandwiched-carbon-passivation-layer-high-efficiency-002008nas a2200193   4500008004100000022001400041245013500055210006900190260011000259300001400369490000600383520117100389100002401560700002901584700002201613700002501635700003001660856012401690       2014                        eng d  a2040-336400aElectrochemical preparation of vertically aligned, hollow CdSe nanotubes and their p-n junction hybrids with electrodeposited Cu2O0 aElectrochemical preparation of vertically aligned hollow CdSe na  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG  a9148-91560 v63 a<p>Vertically aligned, hollow nanotubes of CdSe are grown on fluorine doped tin oxide (FTO) coated glass substrates by ZnO nanowire template-assisted electrodeposition technique, followed by selective removal of the ZnO core using NH4OH. A detailed mechanism of nucleation and anisotropic growth kinetics of nanotubes have been studied by a combination of characterization tools such as chronoamperometry, SEM and TEM. Interestingly, ``as grown'' CdSe nanotubes (CdSe NTs) on FTO coated glass plates behave as n-type semiconductors exhibiting an excellent photo-response (with a generated photocurrent density value of similar to 470 mu A cm(-2)) white in contact with p-type Cu2O (p-type semiconductor, grown separately on FTO plates) because of the formation of a n-p heterojunction (type II). The observed photoresponse is 3 times higher than that of a similar device prepared with electrodeposited CdSe films (not nanotubes) and Cu2P on FTO. This has been attributed to the hollow 1-D nature of CdSe NTs, which provides enhanced inner and outer surface areas for better absorption of light and also assists faster transport of photogenerated charge carriers.</p>1 aDebgupta, Joyashish1 aDevarapalli, Rami, Reddy1 aRahman, Shakeelur1 aShelke, Manjusha, V.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/electrochemical-preparation-vertically-aligned-hollow-cdse-nanotubes-and-their-p-n-001364nas a2200193   4500008004100000022001400041245012200055210006900177260007100246300001400317490000600331520059200337100001800929700002100947700002400968700003000992700001701022856013101039       2014                        eng d  a2161-165300aMitigating the cytotoxicity of graphene quantum dots and enhancing their applications in bioimaging and drug delivery0 aMitigating the cytotoxicity of graphene quantum dots and enhanci  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a1064-10680 v33 a<p>Despite the promising photophysical properties of fluorescent graphene quantum dots (GQDs), their cellular toxicity needs to be addressed before their full potential could be completely realized in biomedicine. A simple method for mitigating the toxicity of GQDs by embedding them in PEG matrix is reported here. The enhanced biocompatibility of polymer modified, P-GQDs, is attributed to reduced reactive oxygen species generation, as measured by an intracellular ROS assay. We also demonstrate the enhanced loading and efficient intracellular delivery of therapeutics by P-GQDs.</p>1 aChandra, Anil1 aDeshpande, Sonal1 aShinde, Dhanraj, B.1 aPillai, Vijayamohanan, K.1 aSingh, Neetu  uhttps://library.ncl.res.in/content/mitigating-cytotoxicity-graphene-quantum-dots-and-enhancing-their-applications-bioimaging-002711nas a2200289   4500008004100000022001400041245014600055210006900201260007100270300001200341490000600353520162200359653005601981653002102037653001302058653002702071653003502098100001602133700002402149700001402173700001502187700001602202700002402218700003002242700002302272856012602295       2014                        eng d  a1936-085100aSequential electrochemical unzipping of single-walled carbon nanotubes to graphene ribbons revealed by in situ Raman spectroscopy and imaging0 aSequential electrochemical unzipping of singlewalled carbon nano  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN  a234-2420 v83 a<p>We report an in situ Raman spectroscopic and microscopic investigation of the electrochemical unzipping of single-walled carbon nanotubes (SWNTs). Observations of the radial breathing modes (RBMs) using Raman spectral mapping reveal that metallic SWNTs are opened up rapidly followed by gradual unzipping of semiconducting SWNTs. Consideration of the resonant Raman scattering theory suggests that two metallic SWNTs with chiralities (10,4) and (12, 0) get unzipped first at a lower electrode potential (036 V) followed by the gradual unzipping of another two metallic tubes, (9, 3) and (10, 1), at a relatively higher potential (1.16 V). The semiconducting SWNTs with chiralities (11, 7) and (12, 5), however, get open up gradually at +/- 1.66 V. A rapid decrease followed by a subsequent gradual decrease in the metallicity of the SWNT ensemble as revealed from a remarkable variation of the peak width of the G band complies well with the variations of RBM. Cyclic voltammetry also gives direct evidence for unzipping in terms of improved capacitance after oxidation followed by more important removal of oxygen functionalities during the reduction step, as reflected in subtle changes of the morphology confirming the formation of graphene nanoribbons. The density functional-based tight binding calculations show additional dependence of chirality and diameter of nanotubes on the epoxide binding energies, which is in agreement with the Raman spectroscopic results and suggests a possible mechanism of unzipping determined by combined effects of the structural characteristics of SWNTs and applied field.</p>10adensity functional-based tight binding calculations10aElectrochemistry10agraphene10aRaman spectral mapping10asingle-walled carbon nanotubes1 aJohn, Robin1 aShinde, Dhanraj, B.1 aLiu, Lili1 aDing, Feng1 aXu, Zhiping1 aVijayan, Cherianath1 aPillai, Vijayamohanan, K.1 aPradeep, Thalappil  uhttps://library.ncl.res.in/content/sequential-electrochemical-unzipping-single-walled-carbon-nanotubes-graphene-ribbons-000694nas a2200169   4500008004100000022001400041245009600055210006900151260005700220300001200277490000600289100002400295700002400319700003000343700002500373856012600398       2015                        eng d  a1868-252900aCo3O4 nanorods-efficient non-noble metal electrocatalyst for oxygen evolution at neutral pH0 aCo3O4 nanorodsefficient nonnoble metal electrocatalyst for oxyge  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUL  a331-3400 v61 aRamsundar, Rani, M.1 aDebgupta, Joyashish1 aPillai, Vijayamohanan, K.1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/co3o4-nanorods-efficient-non-noble-metal-electrocatalyst-oxygen-evolution-neutral-ph-002323nas a2200241   4500008004100000022001400041245014400055210006900199260010200268300001200370490000700382520137800389653001501767653001101782653001101793653003001804653001401834100002401848700002401872700002401896700003001920856013101950       2015                        eng d  a0250-470700aElectrochemical preparation of nitrogen-doped graphene quantum dots and their size-dependent electrocatalytic activity for oxygen reduction0 aElectrochemical preparation of nitrogendoped graphene quantum do  aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScAPR  a435-4420 v383 a<p>Here we report a remarkable transformation of nitrogen-doped multiwalled carbon nanotubes (MWCNTs) to size selective nitrogen-doped graphene quantum dots (N-GQDs) by a two-step electrochemical method. The sizes of the N-GQDs strongly depend on the applied anodic potential, moreover increasing potential resulted in a smaller size of N-GQDs. These N-GQDs display many unusual size-dependant optoelectronic (blue emission) and electrocatalytic (oxygen reduction) properties. The presence of N dopants in the carbon framework not only causes faster unzipping of MWCNTs but also provides more low activation energy site for enhancing the electrocatalytic activity for technologically daunting reactions like oxygen reduction. The smaller size of N-GQDs has shown better performance as compared to the large N-GQDs. Interestingly, N-GQDs-3 (size = 2.5 +/- 0.3 nm, onset potential = 0.75 V) show a 30-mV higher positive onset potential shift compared to that of N-GQDs-2 (size = 4.7 +/- 0.3 nm, onset potential = 0.72 V) and 70 mV than that of N-GQDs-1 (size = 7.2 +/- 0.3, onset potential = 0.68 V) for oxygen reduction reaction (ORR) in a liquid phase. These result in the size-dependent electrocatalytic activity of N-GQDs for ORR as illustrated by the smaller sized N-GQDs (2.5 +/- 0.3 nm) undoubtedly promising metal-free electrocatalysts for fuel cell applications.</p>10afuel cells10aMWCNTs10aN-GQDs10aoxygen reduction reaction10aunzipping1 aShinde, Dhanraj, B.1 aDhavale, Vishal, M.1 aKurungot, Sreekumar1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/electrochemical-preparation-nitrogen-doped-graphene-quantum-dots-and-their-size-dependent-001909nas a2200205   4500008004100000022001400041245009600055210006900151260011000220300001600330490000700346520109400353100001801447700001701465700002201482700002201504700003001526700002201556856012501578       2015                        eng d  a1463-907600aFractional photo-current dependence of graphene quantum dots prepared from carbon nanotubes0 aFractional photocurrent dependence of graphene quantum dots prep  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG  a24566-245690 v173 a<p>We report on the photo-conductivity studies of chemically synthesized graphene quantum dots (GQDs) of average size 12 nm obtained by the oxidative acid treatment of MWCNTs. The dependence of photocurrent I-ph (I-ph = I-ill - I-dark) on the laser intensity P under a wide range of laser intensities (5 mW &lt;= P &lt;= 60 mW) shows a fractional power dependence of I-ph on light intensity. The temperature dependence (300 K &lt; T &lt; 50 K) of I-ph observed in thin films of these GQDs indicates that in the higher temperature region (T &gt; similar to 100 K), as the temperature increases, the number of thermally generated carriers increase resulting in increased I-ph. At sufficiently low temperatures (T &lt;= 100 K), a constant I-ph is observed, indicating a constant photocarrier density. Such a behavior is typically observed in many photoactive disordered semiconductors, which are often used in a variety of applications. We believe that the investigations presented here will enhance our understanding of the photocurrent generation phenomenon in chemically obtained GQDs.</p>1 aKundu, Sumana1 aGhosh, Sujoy1 aFralaide, Michael1 aNarayanan, T., N.1 aPillai, Vijayamohanan, K.1 aTalapatra, Saikat  uhttps://library.ncl.res.in/content/fractional-photo-current-dependence-graphene-quantum-dots-prepared-carbon-nanotubes-001616nas a2200205   4500008004100000245005400041210005400095260000800149300002700157490000800184520096300192100002301155700002401178700002401202700002301226700002101249700003001270700002401300856008601324       2015                        eng d00aGraphene nanoribbons as prospective field emitter0 aGraphene nanoribbons as prospective field emitter  cJAN  aArticle Number: 0231110 v1063 a<p>Field emission characteristics of graphene nanoribbons (GNRs) synthesized by unzipping of multiwall carbon nanotubes using a facile hydrothermal route have been investigated at a base pressure of 1 x 10(-8) mbar. The values of turn-on field, required to draw an emission current densities of 1 and 10 mu A/cm(2), are found to be 2.8 and 5.8 V/mu m, respectively, and a maximum emission current density of 500 mu A/cm(2) has been drawn at an applied field of 9.8 V/mu m. The emission current stability of the GNRs emitter was studied at preset values of 1 and 10 mu A over a period of 3 h, and is found to be excellent. The field emission results demonstrated herein suggest that GNRs based field emitters can open up many opportunities for their potential utilization as large area field emitters in various vacuum micro-nanoelectronic devices such as flexible field emission displays, portable X-ray, and microwave tubes. (C) 2015 AIP Publishing LLC.</p>1 aKhare, Ruchita, T.1 aShinde, Dhanraj, B.1 aBansode, Sanjeewani1 aMore, Mahendra, A.1 aMajumder, Mainak1 aPillai, Vijayamohanan, K.1 aLate, Dattatray, J.  uhttps://library.ncl.res.in/content/graphene-nanoribbons-prospective-field-emitter01320nas a2200181   4500008004100000022001400041245010600055210006900161260011000230300001600340490000700356520055300363100002100916700002400937700002400961700003000985856012301015       2015                        eng d  a1359-734500aRole of the molecular structure of carboxylate-alumoxanes in the enhanced nucleation of polypropylene0 aRole of the molecular structure of carboxylatealumoxanes in the   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAY  a10026-100290 v513 a<p>We have reported the use of carboxylate-alumoxanes as efficient nucleating agents for isotactic polypropylene (iPP) with a possible structural correlation to the nucleation efficiency. The unique, butterfly-like structure of carboxylate-alumoxanes correlates well with the nucleation characteristics of iPP and, for the first time, the impact of a thermally induced, crystalline transition of carboxylate-alumoxanes, which alters neither the structural conformation nor the nucleation efficiency of the transformed material, is demonstrated.</p>1 aMani, Mohan, Raj1 aChellaswamy, Ramesh1 aMarathe, Yogesh, N.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/role-molecular-structure-carboxylate-alumoxanes-enhanced-nucleation-polypropylene-001490nas a2200205   4500008004100000245005900041210005700100260000800157300001600165490000600181520084400187100001801031700002401049700002201073700002501095700001901120700002501139700003001164856009001194       2015                        eng d00aSynthesis of N, F and S co-doped graphene quantum dots0 aSynthesis of N F and S codoped graphene quantum dots  cMAY  a11515-115190 v73 a<p>Graphene quantum dots (GQDs) are a promising category of materials with remarkable size dependent properties like tunable bandgap and photoluminescence along with the possibility of effective chemical functionalization. Doping of GQDs with heteroatoms is an interesting way of regulating their properties. Herein, we report a facile and scalable one-step synthesis of luminescent GQDs, substitutionally co-doped with N, F and S, of similar to 2 nm average size by a microwave treatment of multi-walled carbon nanotubes in a customized ionic liquid medium. The use of an ionic liquid coupled with the use of a microwave technique enables not only an ultrafast process for the synthesis of co-doped GQDs, but also provides excellent photoluminescence quantum yield (70%), perhaps due to the interaction of defect clusters and dopants.</p>1 aKundu, Sumana1 aYadav, Ram, Manohar1 aNarayanan, T., N.1 aShelke, Manjusha, V.1 aVajtai, Robert1 aAjayan, Pulickel, M.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/synthesis-n-f-and-s-co-doped-graphene-quantum-dots02394nas a2200181   4500008004100000022001400041245014400055210006900199260011000268300001400378490000600392520159400398100002101992700002402013700002402037700003002061856012102091       2016                        eng d  a2046-206900aEnhanced nucleation of polypropylene by metal-organic frameworks (MOFs) based on aluminium dicarboxylates: influence of structural features0 aEnhanced nucleation of polypropylene by metalorganic frameworks   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a1907-19120 v63 a<p>Metal-organic frameworks (MOFs) based on aluminium dicarboxylates provide a new platform for the enhanced nucleation of isotactic polypropylene (iPP). For instance, aluminium dicarboxylates exhibit a unique butterfly-like structure similar to that of carboxylate-alumoxanes and correlates well with the nucleation characteristics of iPP. A subtle change in the structure of the ligand backbone (fumarate/succinate) does not alter the framework structure despite changing the hydrophilic/hydrophobic character and its subsequent nucleation characteristics. This suggests that the nucleating agent should facilitate favourable interaction with hydrophobic iPP for efficient nucleation. Further, a systematic variation of the alkyl chain length in the Al-dicarboxylate does not change the nucleation efficiency considerably, even though it increases the distance between the octahedral alumina chains in the metal-organic framework, suggesting that the butterfly-like structure present in the framework is a key aspect for nucleation. Finally, the significance of the orientational conformation of the dicarboxylate around the metal centre for the nucleation is confirmed by the poor nucleation efficiency of chromium and zirconium suberate MOFs where the orientation of suberate would be different from that of aluminium suberate due to the difference in the ligation of the carboxylate group. The present work thus provides valuable pathways for developing new nucleating agents based on MOFs with appropriate selection and orientation of the organic linkers around the metal centre.</p>1 aMani, Mohan, Raj1 aChellaswamy, Ramesh1 aMarathe, Yogesh, N.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/enhanced-nucleation-polypropylene-metal-organic-frameworks-mofs-based-aluminium-001727nas a2200265   4500008004100000022001400041245011900055210006900174260007500243300001400318490000700332520076500339653001001104653001101114653002101125653001801146653001301164100002201177700002901199700002401228700003001252700002501282700002501307856012901332       2016                        eng d  a0947-653900aFacile green synthesis of BCN nanosheets as high-performance electrode material for electrochemical energy storage0 aFacile green synthesis of BCN nanosheets as highperformance elec  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAY  a7134-71400 v223 a<p>Two-dimensional hexagonal boron carbon nitride (BCN) nanosheets (NSs) were synthesized by new approach in which a mixture of glucose and an adduct of boric acid (H3BO3) and urea (NH2CONH2) is heated at 900 degrees C. The method is green, scalable and gives a high yield of BCN NSs with average size of about 1 mm and thickness of about 13 nm. Structural characterization of the as-synthesized material was carried out by several techniques, and its energy-storage properties were evaluated electrochemically. The material showed excellent capacitive behaviour with a specific capacitance as high as 244 F g(-1) at a current density of 1 A g(-1). The material retains up to 96% of its initial capacity after 3000 cycles at a current density of 5 A g(-1).</p>10aboron10aDoping10aElectrochemistry10aNanoparticles10anitrides1 aKarbhal, Indrapal1 aDevarapalli, Rami, Reddy1 aDebgupta, Joyashish1 aPillai, Vijayamohanan, K.1 aAjayan, Pulickel, M.1 aShelke, Manjusha, V.  uhttps://library.ncl.res.in/content/facile-green-synthesis-bcn-nanosheets-high-performance-electrode-material-electrochemical02889nas a2200181   4500008004100000022001400041245016900055210006900224260007100293300001400364490000700378520209900385100002102484700002402505700002402529700003002553856012402583       2016                        eng d  a0024-929700aNew understanding on regulating the crystallization and morphology of the beta-polymorph of isotactic polypropylene based on carboxylate-alumoxane nucleating agents0 aNew understanding on regulating the crystallization and morpholo  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a2197-22050 v493 a<p>Carboxylate alumoxane derived from p-n-alkylbenzoic acids, where n-alkyl group changes from 2 to 8 carbon atoms, exhibits dual nucleating ability and nucleates isotactic polypropylene (iPP) into predominantly in the beta-phase under specific conditions. The selectivity of the beta-phase nucleation depends on the concentration of the nucleating agent, end melting temperature and cooling rate. The beta-phase obtained from p-n-alkylbenzoate-alumoxanes is compared with the beta-phase obtained from calcium pimelate (CaP), an efficient beta-phase selective, nucleating agent, using the results from DSC, WAXS, and SAXS analysis. The lamellar morphology of iPP nucleated with different nucleating agents crystallized at different crystallization temperatures (T-C) under controlled nonisothermal conditions are evaluated using SAXS analysis. The long period increases with increasing crystallization temperature and the long period of the beta-phase is always larger than that of the alpha-phase for a given crystallization temperature. Furthermore, the variation of long period with crystallization temperature clearly brings out two crystallization temperature ranges; the low temperature range and the high temperature range. However, the beta-phase shows a lower changeover temperature compared to that of the alpha-phase. The one-dimensional correlation analysis of the beta-phase shows that the thickness of the crystal lamellae (lc) increases with T-C and exhibits the low and high crystallization temperature ranges, while the thickness, of the amorphous layer (la) more or less remains constant. In-situ high temperature WAXS studies capture the beta-phase to the a-phase transition and the transformed material con-elates well with the lamellar thickness of the beta-phase. The morphological difference between the alpha- and the beta-phases are discussed and attributed to the differences in the impact properties and the melting temperature. This study clearly demonstrates that the lamellar morphology mainly depends on the T-C and not on the nature of the nucleating agents.</p>1 aMani, Mohan, Raj1 aChellaswamy, Ramesh1 aMarathe, Yogesh, N.1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/new-understanding-regulating-crystallization-and-morphology-beta-polymorph-isotactic01784nas a2200229   4500008004100000022001400041245010700055210006900162260000900231300001200240490000700252520098500259100003001244700001701274700001501291700002701306700001701333700001901350700003001369700002401399856013101423       2019                        eng d  a1948-718500aRole of structural distortion in stabilizing electrosynthesized blue emitting phosphorene quantum dots0 aRole of structural distortion in stabilizing electrosynthesized   cMAR   a973-9800 v103 a<p>Luminescent phosphorene quantum dots (PQDs) have emerged as fascinating nanomaterials for potential applications in optoelectronics, catalysis, and sensing. Herein, we investigate the structural distortion of black phosphorus (BP) under an applied electric field to yield blue luminescent PQDs [average diameter 8 +/- 1.5 nm (N = 60)]. The electrosynthesized PQDs exhibit photoluminescence emission independent of excitation wavelength with 84% quantum efficiency. Structural distortion that occurred during the transformation of BP to PQDs is confirmed by results obtained during transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Further, using first-principles-based density functional theory, calculations on oxygenated and nonoxygenated PQDs augment the experimental observations that an optimum oxygen content maintains the structural integrity of PQDs, above which the structural robustness of PQDs is drastically diminished.</p>
1 aValappil, Manila, Ozhukil1 aJoshi, Krati1 aJohn, Lisa1 aKrishnamurthy, Sailaja1 aJana, Bikash1 aPatra, Amitava1 aPillai, Vijayamohanan, K.1 aAlwarappan, Subbiah  uhttps://library.ncl.res.in/content/role-structural-distortion-stabilizing-electrosynthesized-blue-emitting-phosphorene-quantum