01836nas a2200169 4500008004100000022001400041245019100055210006900246260007100315300001400386490000800400520106600408100001501474700001801489700003001507856012901537 2013 eng d a1932-744700aDesign and performance aspects of a custom-built ambient pressure photoelectron spectrometer toward bridging the pressure gap: oxidation of Cu, Ag, and Au surfaces at 1 mbar O-2 pressure0 aDesign and performance aspects of a custombuilt ambient pressure a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR a4717-47260 v1173 a

The critical features of a custom-built laboratory version ambient pressure photoelectron spectrometer (Lab-APPES) are presented. A double front cone differential pumping arrangement and an aperture free design employed in the electrostatic lens regime improve the data collection and data quality. In contrast to the conventional X-ray photoelectron spectrometers (XPS) operating at ultrahigh vacuum (UHV), it is possible to explore the electronic structure of solid surfaces under working conditions or closer to working conditions with Lab-APPES. Especially surface-dependent phenomena can be explored up to 1 mbar pressure and up to 873 K by conventional heating methods and at least up to 1273 K by a laser heating method. Simultaneous XPS and reaction kinetic measurements on solid surfaces make the Lab-APPES an important tool to measure the dynamic electronic structure changes on material surfaces under reaction conditions. The interaction of O-2 with polycrystalline foils of Cu, Ag, and Au from UHV to 1 mbar and up to 773 K has been studied.

1 aRoy, Kanak1 aVinod, C., P.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/design-and-performance-aspects-custom-built-ambient-pressure-photoelectron-spectrometer-001751nas a2200265 4500008004100000022001400041245008800055210006900143260007300212300001200285490000800297520080800305653002201113653002501135653002801160653002201188653002001210653001801230653001401248100002401262700003301286700002201319700003001341856011401371 2013 eng d a0926-860X00aDisordered mesoporous V/TiO2 system for ambient oxidation of sulfides to sulfoxides0 aDisordered mesoporous VTiO2 system for ambient oxidation of sulf aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB a132-1380 v4523 a

High sulfide conversion and predominant sulfoxide yield has been observed with 0.1% vanadium doped disordered mesoporous Ti1-xVxO2 material at ambient and sub ambient temperatures using environmentally green H2O2 oxidant. Ti1-xVxO2 materials were prepared by one-pot solution combustion method in less than 15 min and thoroughly characterized by X-ray diffraction, HRTEM, Raman spectra and other physicochemical techniques. Different sulfides, such as, phenylsulfide, methyl-p-tolylsulfide, ethylsulfide, thioanisole, were converted into the corresponding sulfoxide. Isolated V5+ incorporated in the TiO2 lattice is likely to be the active species for the sulfide oxidation reaction. Catalyst recycling studies indicates the robustness of the catalyst. (c) 2012 Elsevier B.V. All rights reserved.

10aAmbient oxidation10aCombustion synthesis10aheterogeneous catalysis10aHydrogen peroxide10aMesoporous TiO210aSulfoxidation10aSulfoxide1 aNegi, Sanjay, Singh1 aSivaranjani, Kumarsrinivasan1 aSingh, Anand, Pal1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/disordered-mesoporous-vtio2-system-ambient-oxidation-sulfides-sulfoxides-002674nas a2200265 4500008004100000022001400041245011200055210006900167260007700236300001200313490000600325520169700331653002802028653001302056653002502069653001902094653002002113100003302133700002502166700001602191700001502207700002702222700003002249856012902279 2014 eng d a1867-388000aDisordered mesoporous TiO2-xNx+Nano-Au: an electronically integrated nanocomposite for solar H-2 generation0 aDisordered mesoporous TiO2xNxNanoAu an electronically integrated aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a522-5300 v63 a

We report on H-2 generation by photocatalysis driven by simulated white light by electronically integrated Au nanoparticles with multifunctional, disordered mesoporous TiO2-xNx (Au-NT) nanocomposites. Solar H-2 generation (1.5 mmolh(-1)g(-1)) from aqueous methanol has been demonstrated with Au-NT nanocomposites. The water splitting activity of Au-NT is attributed to the 21.1 ps lifetime of charge carriers observed from fluorescence lifetime measurements, which indicates a high electron-injection efficiency from nano-Au to the conduction band of TiO2, and hence charge separation as well as utilization. This is directly supported by the observation of a high photoluminescence emission intensity with Au-NT that highlights the energy transfer from nano-Au to TiO2. The p-n heterojunction observed between the Au (001) and TiO2 (101) facets helps to-wards the higher charge separation and their utilization. A low mesochannel depth (< 10 nm) associated with disordered mesoporous TiO2-xNx helps the charge carriers to move towards the surface for redox reactions and hence charge utilization. Visible-light absorption, as a result of the surface plasmon resonance of nano-Au, is observed in a broad range between 500 and 750 nm, which helps in harvesting visible-light photons. Finally, electronically integrated nano-Au with TiO2-xNx in Au-NT is evident from Raman and X-ray photoelectron spectroscopy measurements. All of these factors help to achieve a high rate of H-2 production. It is likely that a higher rate of H-2 production than that reported here is feasible by strategically locating Au clusters in porous TiO2 to generate hot spots through electronic integration.

10aheterogeneous catalysis10aHydrogen10amesoporous materials10aphotochemistry10awater splitting1 aSivaranjani, Kumarsrinivasan1 aRajaambal, Sivaraman1 aDas, Tanmay1 aRoy, Kanak1 aBhattacharyya, Somnath1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/disordered-mesoporous-tio2-xnxnano-au-electronically-integrated-nanocomposite-solar-h-2-001799nas a2200181 4500008004100000022001400041245012100055210006900176260000900245300001400254490000600268520112600274100002601400700001601426700003001442700001801472856012701490 2017 eng d a2044-475300aDiverse reactivity trends of Ni surfaces in Au@Ni core-shell nanoparticles probed by near ambient pressure (NAP) XPS0 aDiverse reactivity trends of Ni surfaces in AuNi coreshell nanop cOCT  a4489-44980 v73 aA mild temperature sequential reduction method in aqueous medium is reported for the synthesis of Au@Ni nanoparticles with a core-shell morphology. The nickel shell thickness with a gold core in the nanostructure can be tuned from 2 nm up to about 10 nm. Near ambient pressure XPS (NAPXPS) studies under oxygen atmosphere show that Au-80@Ni-20 with an extremely thin nickel shell (similar to 2 nm) follows a distinctly different decomposition pathway of metastable Ni(OOH) species compared to those with larger shell thickness which behave more like individual nickel surfaces. Thus, Ni(OOH) on Au-80@Ni-20 decomposes to metallic Ni at 100 degrees C and is found to resist oxidation at 0.1 mbar oxygen at this temperature. Those with a larger nickel shell thickness behave more like monometallic Ni in terms of their decomposition and oxidation properties. The Au@Ni system with an ultra thin metallic nickel overlayer (2 nm) shows high catalytic activity and selectivity for phenylacetylene hydrogenation under mild conditions which outweighs their monometallic counterparts and those with higher nickel shell thickness.1 aBharathan, Vysakh, A.1 aJain, Ruchi1 aGopinath, Chinnakonda, S.1 aVinod, C., P. uhttps://library.ncl.res.in/content/diverse-reactivity-trends-ni-surfaces-auni-core-shell-nanoparticles-probed-near-ambient01646nas a2200229 4500008004100000022001400041245009800055210006900153260000900222300001400231490000700245520085500252100001801107700002601125700002201151700001801173700001801191700002701209700003001236700002001266856013001286 2018 eng d a1144-054600aDeposition of Au nanoparticles inside porous CeO2 nanocubes using Langmuir-Blodgett technique0 aDeposition of Au nanoparticles inside porous CeO2 nanocubes usin cJAN  a1379-13860 v423 a

Porous 3D CeO2 nanocubes were synthesized using hot injection technique. These nanocubes were able to form a stable monolayer over water and HAuCl4 subphase in Langmuir-Blodgett (LB) trough due to the presence of surface capped oleic acid and oleylamine. CeO2-Au nanocomposites were synthesized exploiting the ability of oleylamine to reduce AuCl4 ions to Au-0, via LB method. CeO2 nanocubes gave rise to excellent long-range assembly at air/water interface and gold nanoparticles were formed inside these porous nanocubes without disturbing this arrangement. The formation of a stable monolayer was evidenced from the surface pressure-area (P-A) isotherm. The development of Au nanoparticles was confirmed with great effort from a comprehensive study using UV-Vis spectroscopy, XRD, XPS, FTIR, TEM, STEM, EDX, tomography and chemical mapping.

1 aDas, Subhasis1 aBhattacharjee, Gourab1 aSatpati, Biswarup1 aKumar, Mukesh1 aDeka, Sasanka1 aGhosalya, Manoj, Kumar1 aGopinath, Chinnakonda, S.1 aBala, Tanushree uhttps://library.ncl.res.in/content/deposition-au-nanoparticles-inside-porous-ceo2-nanocubes-using-langmuir-blodgett-technique02229nas a2200181 4500008004100000022001400041245011500055210006900170260000800239300001400247490000600261520154900267100002801816700002901844700001901873700003001892856012501922 2019 eng d a2050-748800aDirect solar-to-hydrogen generation by quasi-artificial leaf approach: possibly scalable and economical device0 aDirect solartohydrogen generation by quasiartificial leaf approa cFEB a3179-31890 v73 a

Often, a disadvantage in one area of science may become an advantage in another area. In contrast, a successful concept in one area could work for a complementary area of research too. These two philosophies have been successfully used for solar hydrogen generation and they underscore the necessity to connect relevant concepts. We, herein, report a quasi-artificial leaf (QuAL) device in a wireless configuration with a TiO2/Mn-CdS composite and NiCu as a co-catalyst for possibly scalable as well as commercially viable solar hydrogen production under one sun conditions. The device works at no applied potential and generates 10.5 mL h(-1) (16 mL h(-1)) H-2 with Ni5Cu2.5 alloy (Pt) as a co-catalyst, which corresponds to a power conversion efficiency (PCE) of 4.8% (7.3%). The significant resemblance of NiCu alloy to Pt in terms of its electrochemical activity and electronic structure makes the device more economical. While the millisecond lifetime of electrons in Mn-CdS is known to help for white light emission, the same factor helps to greatly improve charge utilization for H-2 production in the QuAL device. In contrast, the reabsorption of emitted light is a vexing problem in emission applications; however in the present work, reabsorption is successfully utilized to enhance hydrogen yield. Spectroscopy techniques combined with electrocatalytic studies were employed and the results correlated with solar hydrogen generation, demonstrating this as a new pathway to design better solar-light-harvesting architectures.

1 aPatra, Kshirodra, Kumar1 aBharad, Pradnya, Arunrao1 aJain, Vanshika1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/direct-solar-hydrogen-generation-quasi-artificial-leaf-approach-possibly-scalable-and02344nas a2200181 4500008004100000022001400041245017700055210006900232260000800301300001600309490000600325520161800331100001701949700001701966700003001983700001802013856013102031 2020 eng d a2050-748800aDirected holey and ordered g-C(3)N(4.5)nanosheets by a hard template nanocasting approach for sustainable visible-light hydrogen evolution with prominent quantum efficiency0 aDirected holey and ordered gC3N45nanosheets by a hard template n cJUL a13328-133390 v83 a

It is desirable yet challenging to synthesize a highly ordered holey carbon nitride material with excess nitrogen atoms for a sustainable solar H(2)evolution. Herein, we report the development of directed highly ordered nitrogen-rich honeycomb-like mesoporous carbon nitride nanosheets by using a novel synthetic approach for this purpose. The unique formation route, surface structure and charge carrier dynamics of the two dimensional holey nanosheets are comprehensively monitored and confirmed by SAXS, HRTEM, AFM, BET, XPS and TRPL analyses. Non-stoichiometric high nitrogen content mesoporous nanosheets with the final stoichiometry of g-C(3)N(4.5)acquiring a high specific surface area (382 m(2)g(-1)), remarkable pore size (7.2 nm) and sheet thickness similar to 5-6 nm are realized in this first report. This elegant material possesses unique low band-gap energy (2.42 eV). Remarkably, the as-synthesized g-C(3)N(4.5)NSs exhibit a record high photocatalytic H(2)evolution rate of 8180 mu mol g(-1)h(-1)under the present light irradiation (420 <=lambda <= 510 nm) condition. The apparent quantum efficiency is found to be as high as 27.14% at 420 nm and retains its photocatalytic activity for longer consecutive catalytic cycles. Bigger pore size and pore volume, and thin walls leading to shortening of the path length of exciton pairs, efficient charge separation and the prolonged average life time of the charge carriers, and lone electron pairs associated with the excess nitrogen content are found to be the reasons behind the excellent visible light driven water splitting reaction.

1 aAntil, Bindu1 aRanjan, Ravi1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka uhttps://library.ncl.res.in/content/directed-holey-and-ordered-g-c3n45nanosheets-hard-template-nanocasting-approach-sustainable02817nas a2200229 4500008004100000022001400041245015400055210006900209260000900278300001400287490000600301520197100307100001802278700002902296700001702325700002302342700002802365700002102393700001802414700003002432856012502462 2024 eng d a2398-490200aDesign of Bi-functional mixed oxide electrodes for selective oxidative C-C cleavage of glycerol to formate and synchronized green hydrogen production0 aDesign of Bifunctional mixed oxide electrodes for selective oxid cJUN  a2954-29680 v83 a

Alkaline water electrolysis is a mature method to produce green hydrogen; however, it suffers from significantly high cost as high overpotentials are required for the oxygen evolution reaction (OER). However, the OER could be avoided altogether by replacing it with kinetically favorable oxidation of abundantly available feedstock molecules at a significantly low potential to value-added product(s) together with green hydrogen generation. This is a potential method to address the high cost of green hydrogen production while converting waste to wealth. Herein, we report green, template-free hydrothermal synthesis of an electrochemically active NiCoMn mixed oxide (NCMO) electrocatalyst with multiple sites, porous structure, large surface area, and nanoneedle (NN) morphology deposited directly over Ni foam (NF). Sustainable electrocatalytic performance was demonstrated for 120 h in 0.2 M alkaline glycerol using chronoamperometry and chronopotentiometry. Highly selective formate production demonstrated an exclusive C-C cleavage with the present catalyst system. Oxides of individual metal-ions (Ni, Co, and Mn) and their bimetallic combination (NiCo, NiMn, and CoMn) exhibited lower activity and product selectivity than the trimetallic NCMO electrocatalyst. The membrane-free two-electrode electrolyzer setup with NCMO/NF at both the anode and cathode (NCMO/NF & Vert;NCMO/NF) requires 1.63 V to accomplish 100 mA cm-2 with 0.2 M glycerol, which is 296 mV less than that of 1 M KOH solution. High faradaic efficiency was observed for hydrogen (98%) with highly selective formate (90%) production. Electrocatalytic formate generation from an alkaline glycerol solution with NCMO is an energy-efficient and promising approach that also supplies carbon-negative green H2. NiCoMn oxide nanoneedles with a cactus-like morphology are shown as bifunctional electrocatalysts that selectively oxidize glycerol to HCOOH and concurrently produce H2.

1 aSaha, Arindam1 aMurugiah, Vasantharadevi1 aRanjan, Ravi1 aChauhan, Inderjeet1 aPatra, Kshirodra, Kumar1 aBajpai, Himanshu1 aSaha, Avisekh1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/design-bi-functional-mixed-oxide-electrodes-selective-oxidative-c-c-cleavage-glycerol