02499nas a2200205   4500008004100000022001400041245012900055210006900184260007300253300001400326490000800340520166300348653001902011653004002030100001902070700002802089700001902117700002602136856013102162       2007                        eng d  a0169-433200aScanning tunneling microscopy/spectroscopy on Au nanoparticles assembled using lauryl amine (LAM) and octadecane thiol (ODT)0 aScanning tunneling microscopyspectroscopy on Au nanoparticles as  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a5109-51150 v2533 a<p>In this report, we demonstrate scanning tunneling microscopy and spectroscopy on thin filins of lauryl amine (LAM) and octadecane thiol (ODT) protected gold nanoparticles. We show that the zero current in the I-V curves (measure of Coulomb blockade (CB) of the nanoparticles) depends on the properties of the spacer molecule. In both the cases the gap voltage and the tunneling current at which the images are obtained are quite different which is further confirmed from the fitting performed based on the orthodox theory. The values for the capacitance and charging energy obtained from the fitting for ODT capped particles are comparable to the values obtained using spherical capacitor model. In contrast, values of these parameters were found to differ for LAM capped nanoparticles. While imaging, ODT capped nanoparticles were observed to drag along the scan direction leading to ordering of particles. Images of LAM capped gold nanoparticles show local ordering in self-assembly of particles although no evidence of large scale ordering in spatial Fourier transform was seen. These observations suggest that nanoparticles with larger CB would be intaged nonevasively in contrast to small CB systems for which tip induced effects will be dominant. In both the systems the current was found to rise faster than theoretical curves based on the orthodox theory suggesting that mechanism of charge transfer in this case may involve field emission rather than tunneling through a rectangular barrier. An attempt has been made to explain charge transfer based on Fowler-Nordheim (F-N) plots of the I-V curves. (c) 2006 Elsevier B.V All rights reserved.</p>10aNanostructures10ascanning tunneling microscopy (STM)1 aDatar, Suwarna1 aChaudhary, Minakshi, V.1 aSastry, Murali1 aDharmadhikari, C., V.  uhttps://library.ncl.res.in/content/scanning-tunneling-microscopyspectroscopy-au-nanoparticles-assembled-using-lauryl-amine-lam01897nas a2200193   4500008004100000022001400041245013100055210006900186260011000255300001400365490000600379520109500385100001801480700001901498700001401517700001701531700002601548856012901574       2013                        eng d  a2040-336400aCharge storage and electron transport properties of gold nanoparticles decorating a urethane-methacrylate comb polymer network0 aCharge storage and electron transport properties of gold nanopar  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a4404-44110 v53 a<p>We propose enhanced charge storage capacity of nanoparticles based polymer films. A flat band voltage window varying from 5-7 V is obtained leading to a trapped charge density of the order of 10(13) cm(-2). These results vary for two distinct morphologies obtained due to decoration of a urethane-methacrylate comb polymer (UMCP) network by gold nanoparticles (AuNPs). Films have been further investigated for morphology, optical, charge storage, and electron transport properties using techniques like scanning electron microscopy (SEM), atomic force microscopy (AFM), absorption spectroscopy (UV-Vis), scanning tunneling microscopy/spectroscopy (STM/STS) and capacitance versus voltage (C-V) measurements. SEM and AFM confirm either the deposition of AuNPs inside the UMCP network or the formation of ring like structures depending on the deposition sequence. STS measurements performed on both films are compared with bare UMCP and AuNPs films. Current versus voltage (I-V) characteristics so obtained are discussed in the light of electron transport mechanisms in such materials.</p>1 aPatil, Sumati1 aDatar, Suwarna1 aRekha, N.1 aAsha, S., K.1 aDharmadhikari, C., V.  uhttps://library.ncl.res.in/content/charge-storage-and-electron-transport-properties-gold-nanoparticles-decorating-urethane-001743nas a2200181   4500008004100000022001400041245009100055210006900146260011000215300001400325490000700339520099800346100002301344700001901367700002901386700002401415856012201439       2015                        eng d  a1744-683X00aHysteretic DC electrowetting by field-induced nano-structurations on polystyrene films0 aHysteretic DC electrowetting by fieldinduced nanostructurations   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a2655-26640 v113 a<p>Electrowetting (EW) offers executive wetting control of conductive liquids on several polymer surfaces. We report a peculiar electrowetting response for aqueous drops on a polystyrene (PS) dielectric surface in the presence of silicone oil. After the first direct current (DC) voltage cycle, the droplet failed to regain Young's angle, yielding contact angle hysteresis, which is close to a value found in ambient air. We conjecture that the hysteretic EW response appears from in situ surface modification using electric field induced water-ion contact with PS surface inducing nano-structuration by electro-hydrodynamic (EHD) instability. Atomic force microscopy confirms the formation of nano-structuration on the electrowetted surface. The effects of molecular weight, applied electric field, water conductivity and pH on nano-structuration are studied. Finally, the EW based nano-structuration on PS surface is used for the enhanced loading of aqueous dyes on hydrophobic surfaces.</p>1 aSawane, Yogesh, B.1 aDatar, Suwarna1 aOgale, Satishchandra, B.1 aBanpurkar, Arun, G.  uhttps://library.ncl.res.in/content/hysteretic-dc-electrowetting-field-induced-nano-structurations-polystyrene-films-001052nas a2200169   4500008004100000245007800041210006900119260000800188300001600196490000700212520046000219100002600679700002200705700001900727700003000746856010600776       2015                        eng d00aPreparation of Ni3S2 and Ni3S2-Ni nanosheets via solution based processes0 aPreparation of Ni3S2 and Ni3S2Ni nanosheets via solution based p  cMAY  a2584–25880 v153 a<p>An easy and convenient preparation of nanometer-thick sheets of Ni3S2 and Ni3S2–Ni from solution processed molecularly thin sheets of Ni-thiolates is described. Both the Ni3S2 and Ni3S2–Ni possessed sheet-like morphologies and displayed room temperature ferromagnetic characteristics. The ferromagnetic nature of these samples was also confirmed by MFM studies, and AFM/TEM investigations substantiated the sheet-like morphology of the samples.</p>1 aBusupalli, Balanagulu1 aDate, Kalyani, S.1 aDatar, Suwarna1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/preparation-ni3s2-and-ni3s2-ni-nanosheets-solution-based-processes02362nas a2200193   4500008004100000022001400041245014400055210006900199260000800268300001600276490000700292520162800299100002301927700001801950700002201968700001901990700003002009856012902039       2016                        eng d  a1463-907600aAttempt to correlate surface physics and chemical properties : molecular beam and Kelvin probe investigations of Ce 1-x Zr x O 2 thin films0 aAttempt to correlate surface physics and chemical properties mol  cSEP  a27594-276020 v183 a<p>What is the correlation between physical properties of the surfaces (such as surface potential, electronic nature of the surface), and chemical and catalysis properties (such as chemisorption, sticking probability of surface)? An attempt has been made to explore any correlation that might exist between the physical and chemical properties of thin film surfaces. Kelvin probe microscopy (KPM) and the molecular beam (MB) methods were employed to carry out the surface potential, and oxygen adsorption and oxygen storage capacity (OSC) measurements on Ce1−xZrxO2 thin films. A sol–gel synthesis procedure and spin-coating deposition method have been applied to make continuous nanocrystalline Ce1−xZrxO2 (x = 0–1) (CZ) thin films with uniform thickness (35–50 nm); however, surface roughness and porosity inherently changes with CZ composition. MB studies of O2 adsorption on CZ reveal high OSC for Ce0.9Zr0.1O2, which also exhibits highly porous and significantly rough surface characteristics. The surface potential observed from KPM studies varied between 30 and 80 mV, with Ce-rich compositions exhibiting the highest surface potential. Surface potential shows large changes after reduction or oxidation of the CZ film demonstrating the influence of Ce3+/Ce4+ on surface potential, which is also a key to catalytic activity for ceria-based catalysts. The surface potential measured from KPM and the OSC measured from MB vary linearly and they depend on the Ce3+/Ce4+ ratio. More and detailed studies are suggested to arrive at a correlation between the physical and chemical properties of the surfaces.</p>1 aKolekar, Sadhu, K.1 aDubey, Anjani1 aDate, Kalyani, S.1 aDatar, Suwarna1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/attempt-correlate-surface-physics-and-chemical-properties-molecular-beam-and-kelvin-probe02179nas a2200181   4500008004100000022001500041245013700056210006900193260000800262300001000270490000700280520148400287100002501771700003001796700002501826700001901851856012701870       2018                        eng d  a 0925-963500a Enhanced microwave absorption property of reduced graphene oxide (RGO)-strontium hexaferrite (SF)/poly (vinylidene) fluoride (PVDF)0 aEnhanced microwave absorption property of reduced graphene oxide  cOCT  a28-340 v893 aEnormous growth in the use of electronic gadgets presents a challenge to develop efficient electromagnetic interference (EMI) shielding materials specifically using composites with properties such as light weight and high shielding due to absorption. In the present work we have synthesized a composite material with three components; Reduced Graphene Oxide (RGO) and Strontium Hexaferrite (SrFe12O19) (SF) bound together by polymer Poly (Vinylidene) Fluoride (PVDF). Composite RGO/SF (RGOSF) was prepared by facile one port chemical reduction method. Surface anchoring of similar to 500 nm of magnetic particles over the graphene sheet was confirmed by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). Crystal structure of SF particles was analyzed before and after composite formation with RGO. Effective crystallite size was estimated from both XRD and Raman Spectroscopy which showed similar trend moving from SF to RGOSF to RGOSFPVDF. Polymer composite films of RGOSFPVDF were prepared by hot pressing. Both real and imaginary part of magnetic and dielectric parameters were studied. It was observed that enhancement of interfacial polarization and anisotropic heat loss in PVDF matrix was generated by RGOSF which ultimately created more scattering center and helped in absorption of electromagnetic radiation. Critical film thickness of 3 mm was capable to shield up to 33 dB EM energy of which > 99.9% was due to absorption.1 aAcharya, Sanghamitra1 aGopinath, Chinnakonda, S.1 aAlegaonkar, Prashant1 aDatar, Suwarna  uhttps://library.ncl.res.in/content/enhanced-microwave-absorption-property-reduced-graphene-oxide-rgo-strontium-hexaferrite02524nas a2200253   4500008004100000022001400041245009000055210006900145260000800214300001400222490000700236520166400243653003001907653002901937653003401966653003602000100001802036700001902054700001802073700002502091700001902116700002602135856010902161       2018                        eng d  a1533-488000aInvestigation of disorder in mixed phase, sp(2)-sp(3) bonded graphene-like nanocarbon0 aInvestigation of disorder in mixed phase sp2sp3 bonded graphenel  cAPR  a2504-25120 v183 a<p>Disorder in a mixed phase, sp(2)-sp(3) bonded graphene-like nanocarbon (GNC) lattice has been extensively studied for its electronic and field emission properties. Morphological investigations are performed using scanning electron microscopy (SEM) which depicts microstructures comprising of atomically flat terraces (c-planes) with an abundance of edges (ab planes which are orthogonal to c-planes). Scanning tunneling microscopy (STM) is used to observe the atomic structure of basal planes whereas field emission microscopy (FEM) is found to be suitable for resolving nanotopography of edges. STM images revealed the hexagonal and non-hexagonal atomic arrangements in addition to a variety of defect structures. Scanning tunneling spectroscopy is carried out to study the effect of this short-range disorder on the local density of states. Current versus voltage (I-V) characteristics have been recorded at different defect sites and are compared with respect to the extent of the defect. As sharp edges of GNC are expected to be excellent field emitters, because of low work function and high electric field, enhancement in current is observed particularly when applied electric field is along basal planes. Therefore, it is worthwhile to investigate field emission from these samples. The FEM images show a cluster of bright spots at low voltages which later transformed into an array resembling ledges of ab-planes with increasing voltage. Reproducible I-V curves yield linear Fowler-Nordheim plots supporting field emission as the dominant mechanism of electron emission. Turn on field for 10 mu A current is estimated to be similar to 3 V/mu m.</p>10aField emission microscopy10aGraphene-Like Nanocarbon10aScanning tunneling microscopy10aScanning Tunneling Spectroscopy1 aPatil, Sumati1 aKolekar, Sadhu1 aKumar, Arvind1 aAlegaonkar, Prashant1 aDatar, Suwarna1 aDharmadhikari, C., V.  uhttps://library.ncl.res.in/content/investigation-disorder-mixed-phase-sp2-sp3-bonded-graphene-nanocarbon02861nas a2200241   4500008004100000022001400041245018000055210006900235260000900304300001600313490000700329520193900336100002602275700002002301700002602321700001702347700003002364700002602394700002102420700001902441700003302460856012602493       2023                        eng d  a1463-907600aPossible handle for broadening the catalysis regime towards low temperatures: proof of concept and mechanistic studies with CO oxidation on surface modified Pd-TiO<sub>2</sub>0 aPossible handle for broadening the catalysis regime towards low   cAUG   a22040-220540 v253 a<p>
	The present work demonstrates the effect of temperature-dependent surface modification (SM) treatment and its influence in broadening the catalysis regime with Pd-TiO2 catalysts prepared by various methods. Due to SM induced changes, a shift in the onset of CO oxidation activity as well as broadening of the oxidation catalysis regime by 30 to 65 K to lower temperatures is observed compared to the temperature required for virgin counterparts. SM carried out at 523 K for Pd-Photo-TiO2 exhibits the lowest onset (10% CO2 production - T-10) and T-100 for CO oxidation at 360 and 392 K, respectively, while its virgin counterpart shows T-10 and T-100 at 393 and 433 K, respectively. The SMd Pd-TiO2 catalysts were investigated using X-ray photoelectron spectroscopy (XPS), ultra-violet photoelectron spectroscopy (UPS) and atomic force microscopy (AFM). It is observed that diffusion of atomic oxygen into Pd-subsurfaces leads to SM and changes the nature of the surface significantly. These changes are demonstrated by work function (&amp; phi;), surface potential, catalytic activity, and correlation among them. UPS results demonstrate the maximum increase in &amp; phi; by 0.5 eV for Pd-Photo-TiO2 after SM, compared to all other catalysts. XPS study shows a moderate to severe change in the oxidation states of Pd due to atomic oxygen diffusion into the subsurface layers of Pd. Kelvin probe force microscopy (KPFM) study also reveals corroborating evidence that the surface potential increases linearly with increasing temperature deployed for SM up to 523 K, followed by a marginal decrease at 573 K. The &amp; phi; measured by KPFM and UPS shows a similar trend and correlates well with the changes in catalysis observed. Our results indicate that there is a strong correlation between surface physical and chemical properties, and &amp; phi; changes could be considered as a global marker for chemical reactivity.</p>
1 aMhamane, Nitin, B. B.1 aPanchal, Suresh1 aKolekar, Sadhu, K. K.1 aRanjan, Ravi1 aSalgaonkar, Kranti, N. N.1 aBurange, Anand, S. S.1 aNalajala, Naresh1 aDatar, Suwarna1 aGopinath, Chinnakonda, S. S.  uhttps://library.ncl.res.in/content/possible-handle-broadening-catalysis-regime-towards-low-temperatures-proof-concept-and02539nas a2200289   4500008004100000022001400041245014400055210006900199260000900268300001600277490000700293520157100300653002101871653001301892653001901905653001301924653001401937653000801951100002301959700002101982700001802003700002302021700001902044700002802063700003002091856012802121       2024                        eng d  a1944-824400aElectrocatalytic glycerol conversion: a low-voltage pathway to efficient carbon-negative green hydrogen and value-added chemical production0 aElectrocatalytic glycerol conversion a lowvoltage pathway to eff  cMAY   a26130-261410 v163 a<p>
	Electrochemical glycerol oxidation reaction (GLYOR) could be a promising way to use the abundantly available glycerol for production of value-added chemicals and fuels. Completely avoiding the oxygen evolution reaction (OER) with GLYOR is an evolving strategy to reduce the overall cell potential and generate value-added chemicals and fuels on both the anode and cathode. We demonstrate the morphology-controlled palladium nanocrystals, afforded by colloidal chemistry, and their established morphology-dependent GLYOR performance. Although it is known that controlling the morphology of an electrocatalyst can modulate the activity and selectivity of the products, still it is a relatively underexplored area for many reactions, including GLYOR. Among nanocube (Pd-NC), truncated octahedron (Pd-TO), spherical and polycrystalline (Pd-PC) morphologies, the Pd-NC electrocatalyst deposited on a Ni foam exhibits the highest glycerol conversion (85%) along with 42% glyceric acid selectivity at a low applied potential of 0.6 V (vs reversible hydrogen electrode (RHE)) in 0.1 M glycerol and 1 M KOH at ambient temperature. Owing to the much favorable thermodynamics of GLYOR on the Pd-NC surface, the assembled electrolyzer requires an electricity input of only similar to 3.7 kWh/m(3) of H-2 at a current density of 100 mA/cm(2), in contrast to the requirement of &gt;= 5 kWh/m(3) of H-2 with an alkaline/PEM electrolyzer. Sustainability has been successfully demonstrated at 10 and 50 mA/cm(2) and up to 120 h with GLYOR in water and simulated seawater.</p>
10aelectrocatalysis10aGlycerol10agreen hydrogen10ananocube10aPalladium10aSDG1 aChauhan, Inderjeet1 aBajpai, Himanshu1 aRay, Bishakha1 aKolekar, Sadhu, K.1 aDatar, Suwarna1 aPatra, Kshirodra, Kumar1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/electrocatalytic-glycerol-conversion-low-voltage-pathway-efficient-carbon-negative-green