01839nas 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-002379nas a2200169   4500008004100000022001400041245014000055210006900195260007100264300001600335490000800351520166000359100002102019700002502040700002402065856012002089       2009                        eng d  a1932-744700aCarbon nanofiber with selectively decorated pt both on inner and outer walls as an efficient electrocatalyst for fuel cell applications0 aCarbon nanofiber with selectively decorated pt both on inner and  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a17572-175780 v1133 a<p>A novel electrocatalyst, with excellent Pi dispersion oil the inner and outer wall of a carbon nanofiber (CNF) was prepared by a modified polyol process in which both surface tension and polarity characteristics of the medium were properly adjusted to favor solution entry into the tubular region by capillary filling and homogeneous wetting of the inner wall surface by the solvents. The pristine CNF, which possesses an inherently active inner wall surface and inactive outer Wall surface, led to selective Pt deposition along the inner wall, whereas activation of the outer wall with chemical functionalization resulted in excellent dispersion of Pt along both inner and outer walls. Structural and morphological characterizations using high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) revealed that when Pt could be dispersed along the inner as well as the Outer walls of CNF, the Pt particle size decreased to almost half as compared to the one With Pt decoration only along a single wall of the Substrate material. Further, electrochemical studies using cyclic voltammetry (CV) and rotating disk electrode (RDE) measurements revealed enhanced methanol oxidation and oxygen reduction properties, respectively. The electrochemical active area obtained for the catalyst with both inner and outer wall Pt decoration wits nearly two times higher than that corresponding to the one with only inner wall Pt decoration. Similarly, the rate constant for the oxygen reduction reaction displayed by this sample was four times higher in comparison with the sample prepared by Utilizing only one wall for Pt decoration.</p>1 aBalan, Beena, K.1 aUnni, SreeKuttan, M.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/carbon-nanofiber-selectively-decorated-pt-both-inner-and-outer-walls-efficient-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-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-002532nas a2200157   4500008004100000022001400041245010500055210006900160260011000229300001600339490000700355520184200362100002102204700002402225856012502249       2011                        eng d  a0959-942800aHighly exposed and activity modulated sandwich type Pt thin layer catalyst with enhanced utilization0 aHighly exposed and activity modulated sandwich type Pt thin laye  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT  a19039-190480 v213 a<p>A Pt thin layer catalyst supported on an in situ prepared `RuO(2)-carbon-RuO(2)' sandwich type hybrid support is presented. This is achieved by the extensive functionalization of a hollow carbon nanofiber support to introduce oxygen containing functional groups (FCNF) with the specific aim to accomplish the exclusive adsorption of Ru ions along its inner cavity and outer surfaces. Preferential adsorption of Ru ions from a mixture of Pt and Ru with sufficient time for adsorption and reorganization of ions on the carbon nanofiber surface leads to the in situ renovation of FCNFs to form a hybrid `RuO(2)-carbon-RuO(2)' sandwich type support followed by Pt nanoparticle decoration. While the selective exposure of Pt on the hybrid support surface is confirmed from the HRTEM analysis, the electronic changes effected in the CNF support are evident from the XPS and XRD analysis. Finally, the potential benefit of such a design is also demonstrated using electrochemical studies, where the three-fold increase in the electrochemically active surface area from cyclic voltammetric analysis, a four-fold improvement in the limiting current density coupled with a 80 mV gain in onset potential from rotating disc electrode studies for the oxygen reduction reaction, and a drastic reduction in the CO poisoning for methanol oxidation reaction underlines the superb performance of this material. Such an exceptionally high performance can be attributed to the strong electronic perturbations occurring in the Pt and the FCNF support due to the presence of a continuous RuO(2) layer in between. Such a high aspect ratio core-shell type design with an unusual enhancement in the Pt utilization establishes the roles of both the hybrid support and active catalyst to address the future challenges in the area of utilization improvement.</p>1 aBalan, Beena, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/highly-exposed-and-activity-modulated-sandwich-type-pt-thin-layer-catalyst-enhanced-001066nas a2200181   4500008004100000022001400041245012000055210006900175260011000244300001400354490000700368520029300375100002100668700002100689700002400710700002000734856013000754       2012                        eng d  a1359-734500aOne-dimensional confinement of a nanosized metal organic framework in carbon nanofibers for improved gas adsorption0 aOnedimensional confinement of a nanosized metal organic framewor  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a2009-20110 v483 a<p>The loading of a Zn-terephthalate based MOF in the inner cavity as well as on the outer walls of a hollow carbon nanofiber (CNF) creates MOF@CNF hybrids. This hybrid ``MOF@CNF'' displayed improved thermal stability as well as gas adsorption compared to the individual counterparts.</p>1 aPachfule, Pradip1 aBalan, Beena, K.1 aKurungot, Sreekumar1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/one-dimensional-confinement-nanosized-metal-organic-framework-carbon-nanofibers-improved-002335nas a2200193   4500008004100000022001400041245013300055210006900188260011000257300001600367490000700383520149300390100002101883700003501904700002701939700002201966700002401988856012902012       2012                        eng d  a0959-942800aPolybenzimidazole mediated N-doping along the inner and outer surfaces of a carbon nanofiber and its oxygen reduction properties0 aPolybenzimidazole mediated Ndoping along the inner and outer sur  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV  a23668-236790 v223 a<p>Nitrogen-doped (N-doped) hollow carbon nanofiber (CNF) was synthesized by incorporating a nitrogen containing polymer precursor, polybenzimidazole (PBI-BuI), in the inner cavity as well as on the outer walls of the CNF, followed by a high temperature treatment. PBI-BuI incorporation along the inner and outer surface of the CNF was accomplished by synthesizing a low molecular weight polymer by tuning the synthetic parameters. The solution concentration of the PBI-BuI is also varied to facilitate its entry into the CNF by capillary action. The high temperature treatment (700-1000 degrees C) of the resulting CNF-PBI material decomposes the polymer and induces N-doping along the inner and outer surfaces of the CNF. The initial PBI-BuI content and the annealing temperature are also systematically varied to choose the right combination of starting precursors and heat-treatment conditions. Detailed X-ray photoelectron spectroscopy analysis of the samples shows that pyridinic-type nitrogen is the major component in all the samples. Electrochemical characterizations of this material using cyclic voltammetry, rotating disc electrode studies and durability analysis demonstrated that this material can act as a metal-free oxygen reduction electrocatalyst with improved oxygen reduction kinetics and stability. It is also revealed that the onset potential, limiting current density, number of transferred electrons, etc. have a strong dependence on the annealing temperature.</p>1 aBalan, Beena, K.1 aManissery, Aiswarya, Padinhare1 aChaudhari, Harshal, D.1 aKharul, Ulhas, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/polybenzimidazole-mediated-n-doping-along-inner-and-outer-surfaces-carbon-nanofiber-and-001390nas a2200205   4500008004100000022001400041245008200055210006900137260009200206300001400298490000700312520060700319653002100926653002600947653002400973653002700997100002101024700002301045856011601068       2012                        eng d  a1533-488000aSignificant enhancement of formic acid oxidation using rhodium nanostructures0 aSignificant enhancement of formic acid oxidation using rhodium n  a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScDEC  a8994-89980 v123 a<p>The electrocatalytic activity of as-synthesized shape selective Rh nanostructures has been demonstrated using cyclic voltammetry, revealing unique shape-dependant performance towards HCOOH oxidation. interestingly, the enhancement factor (R) for different shapes of Rh with respect to that of commercial Rh towards formic acid oxidation ranges up to 20,000% for cubes as compared to 17,500% for pyramids and 11,000% for hexagons respectively. Mechanistic pathway for comparatively better sensitivity of cubes as compared to other shapes has been correlated with the results of X-ray diffraction.</p>10aelectrocatalysis10aFormic Acid Oxidation10aPreferential Growth10aRhodium Nanostructures1 aBalan, Beena, K.1 aSathe, Bhaskar, R.  uhttps://library.ncl.res.in/content/significant-enhancement-formic-acid-oxidation-using-rhodium-nanostructures-002474nas a2200157   4500008004100000022001400041245010600055210006900161260007100230300001400301490000700315520182300322100002102145700002402166856012602190       2012                        eng d  a0020-166900aTuning the functionality of a carbon nanofiber-Pt-RuO2 system from charge storage to electrocatalysis0 aTuning the functionality of a carbon nanofiberPtRuO2 system from  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a9766-97740 v513 a<p>Chemical-functionalization-induced switching in the property of a hybrid system composed of a hollow carbon nanofiber (CNF) and Pt and RuO2 nanoparticles from charge storage to electrocatalysis is presented. The results of this study show how important it is to have a clear understanding of the nature of surface functionalities in the processes involving dispersion of more than one component on various substrates including carbon nanomorphologies. When pristine CNF is used to decorate Pt and RuO2 nanoparticles, random dispersion occurs on the CNF surface (C-PtRuO2). This results in mainly phase-separated nanoparticles rich in RuO2 characteristics. In contrast to this, upon moving from the pristine CNF to those activated by a simple H2O2 treatment to create oxygen-containing surface functional groups, a material rich in Pt features on the surface is obtained (F-PtRuO2). This is achieved because of the preferential adsorption of RuO2 by the functionalized surface of CNF. A better affinity of the oxygen-containing functional groups on CNF toward RuO2 mobilizes relatively faster adsorption of this moiety, leading to a well-controlled segregation of Pt nanoparticles toward the surface. Further reorganization of Pt nanoparticles leads to the formation of a Pt nanosheet structure on the surface. The electrochemical properties of these materials are initially evaluated using cyclic voltammetric analysis. The cyclic voltammetric results indicate that C-PtRuO2 shows a charge storage property, a typical characteristic of hydrous RuO2, whereas F-PtRuO2 shows an oxygen reduction property, which is the characteristic feature of Pt. This clear switch in the behavior from charge storage to electrocatalysis is further confirmed by galvanostatic charge discharge and rotating-disk-electrode studies.</p>1 aBalan, Beena, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/tuning-functionality-carbon-nanofiber-pt-ruo2-system-charge-storage-electrocatalysis-002276nas a2200181   4500008004100000022001400041245010200055210006900157260011000226300001400336490000600350520152300356100002101879700002701900700002201927700002401949856012101973       2013                        eng d  a2046-206900aCarbon nanofiber-RuO2-poly(benzimidazole) ternary hybrids for improved supercapacitor performance0 aCarbon nanofiberRuO2polybenzimidazole ternary hybrids for improv  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC  a2428-24360 v33 a<p>Carbon nanofiber-RuO2-poly(benzimidazole) ternary hybrid electrode material which integrates dual wall decoration and interfacial area tuning for supercapacitor applications has been devised based on a simple approach. This is achieved by decorating RuO2 nanoparticles of size ca. 2-3 nm along the inner and outer walls of a hollow carbon nanofiber (CNF) support (F-20RuO(2)). In the next step, a proton conducting polymer, phosphoric acid doped polybenzimidazole (PBI-BuI), interface is created along the inner and outer surfaces of this material. A 103% increase in the specific capacitance is obtained for RuO2-PBI hybrid material as compared to that of F-20RuO(2) at the optimum level of the polymer wrapping. Apart from the high specific capacitance, the RuO2-PBI hybrid materials exhibit enhanced rate capability and excellent electrochemical stability of 98% retention in the capacitance. Such a remarkably high activity can be primarily attributed to the efficient dispersion of active sites achieved by properly utilizing inner and outer surfaces of CNF. Apart from this, the facile routes for ion transport created as a result of PBI incorporation coupled with excellent interfacial contact between the RuO2 and the electrolyte resulting in the improved utilization of the active material also contribute to the improved activity. In addition to this, the synergistic effects of pseudocapacitive contribution from both the PBI-BuI and RuO2 also contribute to the redefined performance characteristics.</p>1 aBalan, Beena, K.1 aChaudhari, Harshal, D.1 aKharul, Ulhas, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/carbon-nanofiber-ruo2-polybenzimidazole-ternary-hybrids-improved-supercapacitor-002998nas a2200193   4500008004100000022001400041245014300055210006900198260011000267300001400377490000600391520216800397100002102565700001902586700002702605700002202632700002402654856012602678       2013                        eng d  a2050-748800aEffect of the viscosity of poly(benzimidazole) on the performance of a multifunctional electrocatalyst with an ideal interfacial structure0 aEffect of the viscosity of polybenzimidazole on the performance   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a4265-42760 v13 a<p>A novel electrocatalyst system with unique multifunctional characteristics, originated by the presence of a proton conducting polybenzimidazole (PBI-BuI) bound layer and electron conducting hollow carbon nanofibers (CNF) with catalytically active Pt nanoparticles, has been devised based on a simple strategy. This was achieved by decorating Pt nanoparticles along the inner cavity, as well as on the outer walls of the hollow CNF support (F-Pt). In a further extension, a low molecular weight PBI, synthesized by optimizing the experimental parameters, was incorporated into the inner cavity and along the outer surfaces of F-Pt. Excellent dispersion of the Pt nanoparticles was achieved by properly utilizing the available carbon surface results in improved electrocatalytic activity, while the CNF backbone ensures high electron conductivity as well. The polymer binder coverage formed along the inner and outer wall surfaces provides an efficient triple phase boundary (TPB) around the Pt nanoparticles to facilitate the electrode reactions. The amount and the viscosity of the PBI-BuI in the electrode material were systematically varied to study the influence on the electrochemical performance. Transmission electron microscopy analysis confirms PBI insertion into the tubular cavity of CNF. Pore size distribution analysis implies that both the viscosity and the amount of PBI-BuI have a pivotal role in defining the microstructure of the electrode. Electrochemical studies using cyclic voltammetry (CV) and rotating disc electrode (RDE) reveal the exceptionally high activity of this hybrid material with an improved electrochemically active area. The significant improvement for the oxygen reduction reaction is further confirmed by the single cell analysis also. The high power density displayed by the PBI-BuI based system, as compared to the Nafion based system, validates the conceptualization of the well controlled triple-phase boundary in the system. These results demonstrate that PBI-BuI has a constructive effect in tuning the electrochemical activity at an optimum amount and at a favourable viscosity of the proton conducting polymer.</p>1 aBalan, Beena, K.1 aUnni, Bipinlal1 aChaudhari, Harshal, D.1 aKharul, Ulhas, K.1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/effect-viscosity-polybenzimidazole-performance-multifunctional-electrocatalyst-ideal-0