01386nas a2200241 4500008004100000022001400041245008900055210006900144260009500213300001200308490000800320520046100328653002500789653003600814653002800850653003000878100001700908700001800925700003000943700001900973700002600992856012601018 2005 eng d a0021-951700aMCM-41-supported platinum carbonyl cluster-derived asymmetric hydrogenation catalyst0 aMCM41supported platinum carbonyl clusterderived asymmetric hydro a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcJAN a298-3020 v2293 a

Anionic platinum carbonyl cluster has been ion paired with cinchonidium groups that are chemically bound to the surface of MCM-41 and fumed silica. In the hydrogenation of methyl pyruvate or acetophenone the fumed silica-based catalyst gives zero enantioselectivity, but under optimum conditions enantiomeric excesses of >90 and similar to40%, respectively, are obtained with the MCM-41-based catalyst. (C) 2004 Elsevier Inc. All rights reserved.

10aasymmetric catalysis10afunctionalized inorganic oxides10ahydrogenation catalysts10aplatinum carbonyl cluster1 aBasu, Susmit1 aPaul, Himadri1 aGopinath, Chinnakonda, S.1 aBhaduri, Sumit1 aLahiri, Goutam, Kumar uhttps://library.ncl.res.in/content/mcm-41-supported-platinum-carbonyl-cluster-derived-asymmetric-hydrogenation-catalyst-001839nas a2200181 4500008004100000022001400041245007200055210006900127260007100196300001600267490000800283520118100291100002401472700002001496700001401516700003001530856009701560 2005 eng d a1520-610600aMolecular beam study of the NO plus CO reaction on Pd(111) surfaces0 aMolecular beam study of the NO plus CO reaction on Pd111 surface a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL a13272-132820 v1093 a

Nitric oxide (NO) reduction with carbon monoxide (CO) on the Pd(111) surface was studied under isothermal conditions by molecular beam techniques as a function of temperature, NO:CO beam composition, and beam flux. Systematic experiments were performed under transient and steady state conditions. Displacement of adsorbed CO by NO in the transient state of the reaction was observed at temperatures between 375 and 475 K for all the NO: CO compositions studied. NO accumulation occurs on Pd(l 11) surface under steady state conditions, below 475 K, due to stronger chemisorption of NO. The steady state reaction rates attain a maximum at about 475 K, nearly independent of beam composition. N-2 was found to be the major product of the reduction, along with a minor production of N2O. The production of N2 and N2O indicates molecular and dissociative adsorption of NO on Pd(l 11) at temperatures up to 525 K. Postreaction TPD measurements were performed in order to determine the nitrogen coverage under steady-state conditions. Finally, the results are discussed with respect to the rate-controlling character of the different elementary steps of the reaction system.

1 aThirunavukkarasu, K1 aThirumoorthy, K1 aLibuda, J1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/molecular-beam-study-no-plus-co-reaction-pd111-surfaces-002821nas a2200169 4500008004100000022001400041245017300055210006900228260007100297300001600368490000800384520205600392100001902448700002502467700003002492856012902522 2005 eng d a1520-610600aMolecular origins of wettability of hydrophobic poly(vinylidene fluoride) microporous membranes on poly(vinyl alcohol) adsorption: Surface and interface analysis by XPS0 aMolecular origins of wettability of hydrophobic polyvinylidene f a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL a13941-139470 v1093 a

irreversible adsorption of poly(vinyl alcohol) (PVA) on hydrophobic, porous poly(vinylidene fluoride) (PVDF) membranes was carried out using aqueous PVA solution. Water permeation was observed in PVDF microporous membranes after PVA adsorption, and maximum permeability was obtained after treatment with 4% PVA solution. Water permeability increased linearly with increasing PVA concentration up to 4%, and then a marginal decrease with a further increase in PVA concentration occurred. PVA adsorbed PVDF membranes were subjected to intense physicochemical analysis, especially with XPS. XPS results display the presence of an interface between PVA and PVDF, and the binding energy (BE) of the interface is low for the PVDF membranes treated with 4% PVA. Carbon from CF2-groups and F 1s core level clearly showed a decrease in its content on the surface after PVA adsorption and showed a minimum fluorine content at 4% PVA. F Is BE shifts by 0.5 eV upon PVA adsorption and is independent of PVA concentration. EDAX analysis indicates that the bulk oxygen content remains within 4.5 +/- 0.6% and is independent of the PVA concentration. Nonetheless, a large amount of surface atom percentage of oxygen (20 +/- 4%) from 0 Is core level shows an increase in PVA content on the surface of PVDF, and it is restricted mostly to the surface. The 4% PVA treated PVDF membrane clearly shows a broadening of O 1s core level to lower BE and indicates the interaction between PVDF and PVA which is significantly different compared to any other compositions. A new valence band feature at low BE, which is nonexistent on PVDF, develops after PVA adsorption. This indicates that the shift in the nature of the highest occupied molecular orbital (HOMO) derived mostly from oxygen; simultaneously, a suppression in the PVDF derived band indicates the change in nature of the PVA adsorbed surfaces from hydrophobic to hydrophilic. The above observations also suggest an irreversible electronic interaction between PVA and PVDF, possibly through charge transfer.

1 aGholap, S., G.1 aBadiger, Manohar, V.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/molecular-origins-wettability-hydrophobic-polyvinylidene-fluoride-microporous-membranes-002188nas a2200265 4500008004100000022001400041245012200055210006900177260009500246300001200341490000800353520115600361653004001517653002301557653002601580653002801606653003001634100001701664700001701681700003001698700001801728700001901746700002601765856013101791 2006 eng d a0021-951700aMCM-41-supported platinum carbonyl cluster-derived catalysts for asymmetric and nonasymmetric hydrogenation reactions0 aMCM41supported platinum carbonyl clusterderived catalysts for as a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcAPR a154-1610 v2393 a

Anionic platinum carbonyl Cluster ([Pt-12(CO)(24)](2-)) was ion-paired with the 3-chloropropyltrimethoxysilyl-ammonium group chemically bound to the surface of MCM-41. The materials undergo quick decarbonylation and have been characterized before decarbonylation by IR and UV-vis spectroscopy and after decarbonylation by XPS and TEM. They have been used as catalysts for the hydrogenations of methyl pyruvate, acetophenone, nitrobenzene, benzonitrile, and ethylacetoacetate. The support and the quaternary ammonium groups have significant effects on surface platinum concentration, crystallite size, and observed activity. In the hydrogenation of the prochiral substrates methyl pyruvate or acetophenone, the cinchonidine-based catalyst gives significant enantioselectivity under optimum conditions. A kinetic model that includes an enantioselective product-formation step and a hydrogen pressure-dependent step for the deactivation of the enantioselective sites gives reasonable agreement between predicted and observed enantioselectivity. The model is also in accordance with the XPS and TEM data. (c) 2006 Elsevier Inc. All rights reserved.

10aasymmetric/non-asymmetric catalysis10aEnantioselectivity10afunctionalized MCM-4110ahydrogenation catalysts10aplatinum carbonyl cluster1 aBasu, Susmit1 aMapa, Maitri1 aGopinath, Chinnakonda, S.1 aDoble, Mukesh1 aBhaduri, Sumit1 aLahiri, Goutam, Kumar uhttps://library.ncl.res.in/content/mcm-41-supported-platinum-carbonyl-cluster-derived-catalysts-asymmetric-and-nonasymmetric-101548nas a2200205 4500008004100000022001400041245009600055210006900151260007100220300001400291490000800305520074500313100001901058700003501077700002701112700003001139700001901169700002601188856012801214 2008 eng d a1932-744700aMCM-41-supported organometallic-derived nanopalladium as a selective hydrogenation catalyst0 aMCM41supported organometallicderived nanopalladium as a selectiv a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN a9428-94330 v1123 a

Palladium nanocatalysts have been prepared by anchoring (eta(3)-C(3)H(5))(2)Pd(2)Cl(2) onto dian-tine-functionalized MCM-41 supports followed by reaction with hydrogen under catalytic conditions. The catalyst precursor and used catalyst have been studied by solid-state NMR ((13)C, (29)Si), XPS, and TEM. The organometallic-derived catalyst exhibits the best performance (activity and selectivity) to date toward the selective hydrogenation of industrially relevant o- and m-chloronitrobenzene to the corresponding chloroaniline derivatives and is distinctly superior to 5% Pd/C. Grazing angle XPS studies reveal that conversion of the tethered molecular species to the nanoparticles of palladium produces a core-shell nanostructure.

1 aMaity, Niladri1 aRajamohanan, Pattuparambil, R.1 aGanapathy, Subramanian1 aGopinath, Chinnakonda, S.1 aBhaduri, Sumit1 aLahiri, Goutam, Kumar uhttps://library.ncl.res.in/content/mcm-41-supported-organometallic-derived-nanopalladium-selective-hydrogenation-catalyst-001233nas a2200265 4500008004100000022001400041245010500055210006900160260007300229300001200302490000800314520025000322653002500572653002600597653002800623653001700651653003100668100001900699700001700718700002900735700003000764700001900794700002600813856012800839 2008 eng d a0926-860X00aMCM-41-supported ruthenium carbonyl cluster-derived catalysts for asymmetric hydrogenation reactions0 aMCM41supported ruthenium carbonyl clusterderived catalysts for a aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a124-1300 v3443 a

{The anionic ruthenium carbonyl cluster [Ru-4(mu-H)(3)(CO)(12)](-) has been ion-paired with (3-chloropropyl)-trimethoxysilyl-cinchonidium or sparteinium groups chemically bound to the surfaces of MCM-41 [(MCM-41-)(-O)(3)SiCH2CH2CH2NR3+Cl-

10aasymmetric catalysis10afunctionalized MCM-4110ahydrogenation catalysts10ananocatalyst10aruthenium carbonyl cluster1 aIndra, Arindam1 aBasu, Susmit1 aKulkarni, Dhanashree, G.1 aGopinath, Chinnakonda, S.1 aBhaduri, Sumit1 aLahiri, Goutam, Kumar uhttps://library.ncl.res.in/content/mcm-41-supported-ruthenium-carbonyl-cluster-derived-catalysts-asymmetric-hydrogenation-001071nas a2200205 4500008004100000022001400041245010800055210006900163260007100232300001400303490000800317520026600325100002100591700001800612700003200630700002400662700001900686700003000705856013000735 2009 eng d a1932-744700aMgCl2 center dot 4(CH3)(2)CHOH: a new molecular adduct and super active polymerization catalyst support0 aMgCl2 center dot 4CH32CHOH a new molecular adduct and super acti a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY a8556-85590 v1133 a

A new molecular adduct, MgCl(2 center dot)4(CH3)(2)CHOH, has been synthesized and characterized for structural aspects and demonstrated for super active ethylene polymerization activity with TiCl4 to ultrahigh molecular weight polyethylene in high yield.

1 aThushara, K., S.1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aBhaduri, Sumit1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mgcl2-center-dot-4ch32choh-new-molecular-adduct-and-super-active-polymerization-catalyst-001846nas a2200229 4500008004100000022001400041245015600055210006900211260011000280300001600390490000700406520088500413100002601298700002101324700002001345700001801365700003201383700002401415700001901439700003001458856012801488 2011 eng d a1477-922600aMgCl2 center dot 6PhCH(2)OH - a new molecular adduct as support material for ziegler-natta catalyst: synthesis, characterization and catalytic activity0 aMgCl2 center dot 6PhCH2OH a new molecular adduct as support mate aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a10936-109440 v403 a

Benzyl alcohol has been used to prepare a single phase MgCl2 center dot 6BzOH molecular adduct as a support for an ethylene polymerization catalyst (Ziegler catalyst). The structural, spectroscopic and morphological aspects of the MgCl2 center dot 6BzOH molecular adduct and the Ziegler catalyst have been thoroughly studied by various physicochemical characterization techniques. The presence of MgO6 octahedrons due to the interaction of Mg2+ with six -OH groups of the benzyl alcohol is confirmed from a Raman feature at 703 cm(-1), and structural studies. The supported catalyst activity has been evaluated for the ethylene polymerization reaction. The lower polymerization activity of the titanated Ziegler-Natta catalyst compared with a standard catalyst is attributed to the strong interaction of titanium chloride with the support and associated electronic factors.

1 aGnanakumar, Edwin, S.1 aThushara, K., S.1 aBhange, Deu, S.1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aBhaduri, Sumit1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mgcl2-center-dot-6phch2oh-new-molecular-adduct-support-material-ziegler-natta-catalyst-001978nas a2200217 4500008004100000022001400041245013400055210006900189260011000258300001600368490000700384520106800391100002101459700002601480700001801506700003201524700002401556700001901580700003001599856013101629 2012 eng d a1477-922600aMgCl2 center dot 4((CH3)(2)CHCH2OH): a new molecular adduct for the preparation of TiClx/MgCl2 catalyst for olefin polymerization0 aMgCl2 center dot 4CH32CHCH2OH a new molecular adduct for the pre aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL a11311-113180 v413 a

A new molecular adduct of MgCl2 with isobutanol, namely MgCl2 center dot 4((CH3)(2)CHCH2OH) (MgiBOH), has been prepared as a precursor to the supporting material for an olefin polymerization catalyst. The MgiBOH adduct and final titanated Ziegler-Natta catalysts have been thoroughly characterized by powder XRD, thermal analysis, Raman spectroscopy and solid-state NMR for structural and spectroscopy aspects. A peak observed at 712 cm(-1) in the Raman spectra of MgiBOH indicates the characteristic Mg-O-6 breathing mode and the formation of the adduct. The diffraction feature at 2 theta = 7.8 degrees (d = 11.223 angstrom) in the XRD confirms the adduct formation and the layered structure. The aim of the present article is to study how the insertion of a bulky isobutanol moiety affects the structural and electronic properties of the MgCl2 isobutanol molecular adduct. Indeed, the focus of the present study is to explore how the presence of isobutanol, in the initial molecular adduct, influences the final Z-N catalyst properties and its activity.

1 aThushara, K., S.1 aGnanakumar, Edwin, S.1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aBhaduri, Sumit1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mgcl2-center-dot-4ch32chch2oh-new-molecular-adduct-preparation-ticlxmgcl2-catalyst-olefin-002012nas a2200229 4500008004100000022001400041245009200055210006900147260007100216300001600287490000800303520114700311100002601458700002101484700002501505700002201530700003201552700002401584700002601608700003001634856011801664 2012 eng d a1932-744700aMgCl2 center dot 6C(6)H(11)OH: a high mileage porous support for ziegler-natta catalyst0 aMgCl2 center dot 6C6H11OH a high mileage porous support for zieg a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a24115-241220 v1163 a

A new and single phase molecular adduct of MgCl2 with six cyclohexanol molecules MgCl2 center dot 6C(6)H(11)OH (MgCyOH) has been synthesized. Structural insight to this adduct was obtained by a variety of physicochemical methods. C-13 CPMAS spectrum and single pulse MAS spectra with high power proton decoupling recorded at different relaxation time showed the presence of two different sets of magnetically unequal cylcohexanol molecules present around Mg2+. A Raman feature of MgCyOH at 712 cm(-1) confirms that cylcohexanol molecules are present around Mg2+ in an octahedral environment. MgCyOH has been used as support material to prepare Ziegler-Natta (Z-N) active catalyst. Textural property of above Z-N catalyst exhibits high surface area (236 m(2)/g) with high porosity. Above active catalyst has been screened for ethylene polymerization. Depending on the cocatalyst employed (Me3Al, Et3Al, and iso-Bu3Al) and ethylene pressure, polyethylene yield varies an order of magnitude, from 378 to 3570 g/g catalyst, indicating a possible creation of different active sites and different interaction between cocatalyst and catalyst.

1 aGnanakumar, Edwin, S.1 aThushara, K., S.1 aGowda, Ravikumar, R.1 aRaman, Sumesh, K.1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aChakraborty, Debashis1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mgcl2-center-dot-6c6h11oh-high-mileage-porous-support-ziegler-natta-catalyst-002142nas a2200169 4500008004100000022001400041245011400055210006900169260011000238300001200348490000700360520139400367100003301761700001801794700003001812856013001842 2012 eng d a1463-926200aMolecular oxygen-assisted oxidative dehydrogenation of ethylbenzene to styrene with nanocrystalline Ti1-xVxO20 aMolecular oxygenassisted oxidative dehydrogenation of ethylbenze aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC a461-4710 v143 a

Oxidative dehydrogenation of ethylbenzene to styrene has been studied with vanadium-incorporated mesoporous nanocrystalline titania (Ti1-xVxO2) and molecular oxygen between 440 and 530 degrees C. Incorporation of V in TiO2 lattice framework has been achieved by simple solution combustion method. Incorporation of V in TiO2 lattice has been confirmed by X-ray diffraction, XPS and Raman spectra and other physicochemical analysis. High ethyl benzene conversion and stable styrene yield has been observed with 10% V-containing rutile phase titania at 500 degrees C. However, stable but relatively lower styrene yield has been observed with 2 and 5% V-containing catalysts between 440 and 500 degrees C. Highest selectivity is observed with lower vanadium content. Comparable activity has been observed under similar experimental conditions with four times higher air-flow than that of O-2. In order to understand the structure activity relationship, spent catalysts were analyzed by all physico-chemical methods. Although there is a phase change from anatase to rutile Ti1-xVxO2 within 1 h of reaction, higher activity is primarily attributed to the ionic V5+ in Ti1-xVxO2 lattice, which prevents agglomeration to V2O5. It is to be underscored the reactivity is retained at the cost of textural properties and phase change from anatase to rutile, which is essential for the reaction.

1 aSivaranjani, Kumarsrinivasan1 aVerma, Akrati1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/molecular-oxygen-assisted-oxidative-dehydrogenation-ethylbenzene-styrene-nanocrystalline-002539nas a2200277 4500008004100000022001400041245012100055210006900176260007100245300001200316490000600328520150200334653002801836653001001864653002101874653002601895653002701921100002601948700002501974700002101999700003202020700002402052700002602076700003002102856012902132 2013 eng d a2155-543500aMgCl2 center dot 6CH(3)OH: a simple molecular adduct and its influence as a porous support for olefin polymerization0 aMgCl2 center dot 6CH3OH a simple molecular adduct and its influe a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR a303-3110 v33 a

A single phase molecular adduct, MgCl2 center dot 6CH(3)OH has been synthesized using MgCl2 and the simplest alcohol, methanol. Structural, spectroscopic, and morphological studies have been carried out for a better understanding of the single phase MgCl2 center dot 6CH(3)OH adduct. C-13 CPMAS solid state NMR studies show all six methanol molecules are magnetically equivalent and present in a single environment around the Mg2+ center. Raman spectral analysis of the characteristic peak at 708 cm(-1) substantiates octahedral coordination of six CH3OH molecules around Mg2+. Solid state C-13 NMR measurements, made after heat treatment at different temperatures, have been utilized to understand the variations in CH3OH stoichiometry and coordination around Mg2+ with temperature. A titanated active catalyst, TiCl4 on MgCl2 center dot 6CH(3)OH, has also been synthesized and subjected to detailed characterizations. The active catalyst shows high surface area (102 m(2)/g) and mesoporosity. The titanated catalyst has been screened for ethylene polymerization reactions using different cocatalysts (R3Al; R= -CH3, -CH2CH3, and -CH2CH(CH3)(2)). A total of 7.25 kg of polyethylene per gram of catalyst has been obtained with Me3Al cocatalyst, which is six times higher in activity compared with commercial Me3Al/TiCl4/MgCl2 center dot 6EtOH-supported orted catalystAlthough porosity influences the catalytic activity, other factors also seem to contribute to the total catalytic activity.

10aheterogeneous catalysis10aMgCl210aMolecular adduct10aolefin polymerization10aZiegler-Natta catalyst1 aGnanakumar, Edwin, S.1 aGowda, Ravikumar, R.1 aKunjir, Shrikant1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aChakraborty, Debashis1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mgcl2-center-dot-6ch3oh-simple-molecular-adduct-and-its-influence-porous-support-olefin-001096nas a2200157 4500008004100000022001400041245009100055210006900146260008800215300001400303490000800317520044100325100001700766700003000783856012500813 2014 eng d a0587-424600aMapping of copper oxidation state using high pressure x-ray photoelectron spectroscopy0 aMapping of copper oxidation state using high pressure xray photo aAL LOTNIKOW 32-46, PL-02-668 WARSAW, POLANDbPOLISH ACAD SCIENCES INST PHYSICScAPR a1065-10660 v1253 a

The interaction of O-2 with polycrystalline foil of Cu, from ultra high vacuum to 1 mbar and up to 773 K has been investigated. The study were performed by using the high pressure X-ray photoelectron spectroscopy (electron spectroscopy for chemical analysis) ultraviolet photoelectron spectroscopy system. In this work the results of mapping copper oxidation states as a function of temperature at 1 mbar O-2 have been presented.

1 aKowalska, J.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mapping-copper-oxidation-state-using-high-pressure-x-ray-photoelectron-spectroscopy-002605nas a2200205 4500008004100000022001400041245010700055210006900162260011000231300001600341490000600357520176600363100002402129700001802153700001602171700002602187700002702213700003002240856012902270 2015 eng d a2040-336400aM-Au/TiO2 (M = Ag, Pd, and Pt) nanophotocatalyst for overall solar water splitting: role of interfaces0 aMAuTiO2 M Ag Pd and Pt nanophotocatalyst for overall solar water aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL a13477-134880 v73 a

M-Au/TiO2 (M = Ag, Pd, Pt) composites were prepared through a facile one-pot photodeposition synthesis and evaluated for solar water splitting (SWS) with and without a sacrificial agent. The M-Au combination exhibits a dominant role in augmenting the H2 generation activity by forming a bi-metallic system. Degussa P25 was used as a TiO2 substrate to photodeposit Au followed by Au + M (M = Ag/Pd/Pt). The SWS activity of the M-Au/TiO2 was determined through photocatalytic H-2 production in the presence of methanol as a sacrificial agent under one sun conditions with an AM1.5 filter. The highest H-2 yield was observed for Pt-0.5-Au-1/TiO2 and was around 1.3 +/- 0.07 mmol h(-1) g(-1), with an apparent quantum yield (AQY) of 6.4%. Pt-0.5-Au-1/TiO2 also demonstrated the same activity for 25 cycles of five hours each for 125 h. Critically, the same Pt-0.5-Au-1/TiO2 catalyst was active in overall SWS (OSWS) without any sacrificial agent, with an AQY = 0.8%. The amount of Au and/or Pt was varied to obtain the optimum composition and it was found that the Pt0.5-Au1/TiO2 composition exhibits the best activity. Detailed characterization by physico-chemical, spectral and microscopy measurements was carried out to obtain an in-depth understanding of the origin of the photocatalytic activity of Pt-0.5-Au-1/TiO2. These in-depth studies show that gold interacts predominantly with oxygen vacancies present on titania surfaces, and Pt preferentially interacts with gold for an effective electron-hole pair separation at Pt-Au interfaces and electron storage in metal particles. The Pt in Pt-0.5-Au-1/TiO2 is electronically and catalytically different from the Pt in Pt/TiO2 and it is predicted that the former suppresses the oxygen reduction reaction.

1 aMelvin, Ambrose, A.1 aIllath, Kavya1 aDas, Tanmay1 aRaja, Thirumalaiswamy1 aBhattacharyya, Somnath1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/m-autio2-m-ag-pd-and-pt-nanophotocatalyst-overall-solar-water-splitting-role-interfaces-002032nas a2200241 4500008004100000022001400041245008300055210006900138260011000207300001400317490000700331520114000338100002201478700001801500700002601518700002201544700001801566700002101584700001601605700003001621700002001651856011901671 2015 eng d a1144-054600aMultifaceted core-shell nanoparticles: superparamagnetism and biocompatibility0 aMultifaceted coreshell nanoparticles superparamagnetism and bioc aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG a8513-85210 v393 a

NicoreAgshell nanoparticles were synthesized by redox transmetallation reaction. Reduction potential match was encouraging to attempt the synthesis of the NicoreAushell system too. However, it could be achieved only after an effective surface modification on the Ni-core. Thorough characterization (UV-Vis spectroscopy, fluorescence spectroscopy, XRD, XPS, FTIR, TEM, and EDX) proved the necessity of surface modification and the success of synthesis of both types of core-shell structures. The chemical composition and topography were determined using STEM-HAADF analysis and EFTEM imaging. Fourier transform infrared (FTIR) spectroscopy confirmed the surface modification of Ni nanoparticles and the interactions involved between the ligands and metals (in the core and/or the shell) at various steps of the synthetic process. Even after the formation of the noble metal shell, the magnetic core was found to retain its superparamagnetic nature. In addition, the Au-shell protected the core from aerial oxidation and decreased toxicity as compared to pristine Ni nanoparticles as observed by MTT assay on normal cells (PBMCs).

1 aSardar, Debasmita1 aNeogi, S., K.1 aBandyopadhyay, Sanjoy1 aSatpati, Biswarup1 aAhir, Manisha1 aAdhikary, Arghya1 aJain, Ruchi1 aGopinath, Chinnakonda, S.1 aBala, Tanushree uhttps://library.ncl.res.in/content/multifaceted-core-shell-nanoparticles-superparamagnetism-and-biocompatibility-001667nas a2200217 4500008004100000245009500041210006900136260000800205300001200213490000600225520093600231653001301167653002001180653002801200653001201228653001601240100001601256700002601272700003001298856012101328 2017 eng d00aMechanistic aspects of wet and dry CO oxidation on Co3O4 nanorod surfaces: a NAP-UPS study0 aMechanistic aspects of wet and dry CO oxidation on Co3O4 nanorod cMAR a828-8340 v23 a

Catalytic activity, electronic structure, and the mechanistic aspects of Co3O4 nanorod (NR) surfaces have been explored for CO oxidation in dry and wet atmosphere using near-ambient pressure ultraviolet photoelectron spectroscopy. Presence of water with CO + O2 plummets the catalytic activity because of the change in the electronic nature from predominantly oxide (without water in feed) to a Co3O4 surface covered by a few intermediates. However, at ≥375 K, the Co3O4 surface recovers and regains the oxidation activity, at least partially, even in the presence of water. This is fully supported by the changes observed in the work function of Co3O4 under wet (H2O + CO + O2) conditions compared with dry (CO + O2) conditions. This study focuses on the comparative CO oxidation rate on Co3O4 NR surfaces and highlights the changes in the electronic structure that occur in the catalyst during the CO oxidation reaction.

10aCatalyst10aNano Structures10aPower X-Ray Diffraction10aspectra10aWater Vapor1 aJain, Ruchi1 aGnanakumar, Edwin, S.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mechanistic-aspects-wet-and-dry-co-oxidation-co3o4-nanorod-surfaces-nap-ups-study02357nas a2200181 4500008004100000022001400041245011900055210006900174260000800243300001600251490000800267520167700275100002901952700001601981700002701997700003002024856012102054 2017 eng d a1932-744700aMetallic cobalt to spinel Co3O4-electronic structure evolution by near-ambient pressure photoelectron spectroscopy0 aMetallic cobalt to spinel Co3O4electronic structure evolution by cOCT a21472-214810 v1213 a

In the present study, valence band (VB) and core level photoelectron spectroscopy was carried out to investigate the electronic structural changes from polycrystalline Co to spinel Co3O4, via CoO at near ambient pressures (NAP; similar to 0.1). O-2 Co and H-2-CoOx gas solid oxidative and reductive interactions, respectively, have been explored with UV photons (He I) or low kinetic energy electrons (<= 16 eV) under NAP conditions. Typical VB features of Co metal, CoOx Co3O4, and a mixed phase between any two adjacent features were observed and well corroborated with core level changes. Very significant and characteristic changes were observed with Co 3d features in the VB for each stage from Co oxidation to Co3O4 as well as Co3O4 reduction to CoOx Co(3O)4 and CoO can be reversibly obtained by alternating the conditions between 0.1 mbar of H-2 at 650 K and 0.1 mbar of O 2 at 400 K, respectively. A meaningful correlation is observed between the changes in work function with cation oxidation state; small changes in the stoichiometry can strongly influence the shift in Fermi level and changes in work function under NAP conditions. Reversible work function changes are observed at a constant BE (similar to 5 ev) between oxidation and reduction conditions. While the O 2 p derived feature for CoOx was observed at throughout the redox conditions, the Co 3d band and molecular oxygen or hydrogen vibration feature shifts significantly underscoring the physicochemical changes, such as charge transfer energy and hence changes in satellite intensity. The peak close to E-F originated from the 3d(6)L final state of the octahedral Co3+ 3d band of Co3O4.

1 aReddy, Kasala, Prabhakar1 aJain, Ruchi1 aGhosalya, Manoj, Kumar1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/metallic-cobalt-spinel-co3o4-electronic-structure-evolution-near-ambient-pressure01720nas a2200205 4500008004100000245013500041210006900176260000800245520093500253100002201188700002401210700002001234700001901254700001801273700002601291700001601317700003001333700002001363856013101383 2017 eng d00aMultiple functionalities of Ni nanoparticles embedded in carboxymethyl guar gum polymer: catalytic activity and superparamagnetism0 aMultiple functionalities of Ni nanoparticles embedded in carboxy cJAN3 aComposites comprising of metallic nanoparticles in polymer matrices have allured significant importance due to multifunctionalities. Here a simple protocol has been described to embed Ni nanoparticles in carboxymethyl guar gum (CMGG) polymer. The composite formation helps in the stabilization of Ni nanoparticles which are otherwise prone towards aerial oxidation. Further the nanoparticles retain their superparamagnetic nature and catalytic capacity. Ni-Polymer composite catalyses the reduction of 4-Nitrophenol to 4-Aminophenol very efficiently in presence of NaBH4, attaining a complete conversion under some experimental conditions. Ni-Polymer composite is well characterized using UV–vis spectroscopy, FTIR, XPS, powder XRD, TGA, SEM and TEM. A detailed magnetic measurement using superconducting quantum interference device-vibrating sample magnetometer (SQUID-VSM) reveals superparamagnetic behaviour of the composite.1 aSardar, Debasmita1 aSengupta, Manideepa1 aBordoloi, Ankur1 aAhmed, Md., A.1 aNeogi, S., K.1 aBandyopadhyay, Sanjoy1 aJain, Ruchi1 aGopinath, Chinnakonda, S.1 aBala, Tanushree uhttps://library.ncl.res.in/content/multiple-functionalities-ni-nanoparticles-embedded-carboxymethyl-guar-gum-polymer-catalytic02684nas a2200181 4500008004100000022001400041245015500055210006900210260000800279300001600287490000800303520195400311100002902265700002302294700002702317700003002344856012802374 2018 eng d a1932-744700aMapping valence band and interface electronic structure changes during the oxidation of Mo to MoO3 via MoO2 and MoO3 reduction to MoO2: A NAPPES study0 aMapping valence band and interface electronic structure changes  cOCT a23034-230440 v1223 a

Tuning the surface energetics, especially work function (phi) of the materials, is of a great deal of interest for a wide range of surface- and interface-based devices and applications. How the phi of a solid surface changes under the reaction conditions is of paramount interest to the chemists, particularly in the areas of surface dependent phenomena such as, catalysis and electrochemistry. In the present study, by using the valence band and core-level photoelectron spectroscopy, surface-electronic changes from Mo to MoO3 via MoO2 was studied under relevant near-ambient pressure (NAP) and high temperature conditions. A very significant change in phi from Mo to MoO3 was observed and it is well corroborated with the changes in gas-phase vibrational features of O-2 in both near-ambient pressure ultraviolet photoelectron spectra (NAPUPS) as well in NAP X-ray photoelectron spectroscopy. Reversible changes in the electronic structure is observed when MoO3 was reduced in H-2 to MoO2. On the basis of the extent of oxidation/reduction of MoOx NAPUPS has shown, one or two additional peaks in the band gap at 0.6 and 1.6 eV below the Fermi level. Mo5+ features are identified in the VB and in the Mo 3d core levels with distinct features. Mo5+ features are also stable and essential to bridge MoO2 and MoO3 layers, and their co-existence. In addition, characteristic changes in Mo 4d and O 2p features observed from Mo to MoO3 and well corelated to the band gap of MoO3. Oxidation and reduction propagate from the surface to bulk; indeed, this has significant implications in surface-dependent phenomena. The present study demonstrates (a) the uniqueness of NAPUPS in identifying the subtle to large changes in the electronic structure on solid surfaces under common oxidation and reduction (in general, under reaction) conditions, and (b) relevance of NAPUPS to all surface dependent phenomena, such as catalysis and electrochemistry.

1 aReddy, Kasala, Prabhakar1 aMhamane, Nitin, B.1 aGhosalya, Manoj, Kumar1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mapping-valence-band-and-interface-electronic-structure-changes-during-oxidation-mo-moo302085nas a2200241 4500008004100000022001400041245011900055210006900174260000800243300001200251490000600263520126900269653002001538653001201558653001801570653001201588653002001600100002601620700001701646700002001663700003001683856013001713 2018 eng d a2194-428800aMarginally hydrogenated triphasic titania nanotubes for effective visible-light photocatalytic hydrogen generation0 aMarginally hydrogenated triphasic titania nanotubes for effectiv cFEB a280-2880 v63 a

We report the first demonstration of hydrogen-annealed triphase TiO nanotubes (anatase-rutile-brookite) (T-ARB) as a visible-light-active photocatalyst for water splitting with high quantum efficiency. As-synthesized T-ARB was annealed under hydrogen atmosphere at 250 and 4508 degrees C for 2 h. We found that the tubular structures were retained in the hydrogenated TiO2 samples. It was observed that the concentrations of Ti3+ and the oxygen vacancies and their distribution significantly increased with respect to the hydrogen annealing temperature. Such changes in defects were found to be critical in enhancing the photocatalytic activity of the hydrogen-annealed triphase TiO2 nanotubes. The triphase TiO2 nanotubes hydrogen annealed at 450 degrees C were 16 times more efficient than pristine TiO2. Such an increase in the photocatalytic activity was explained by a triphase band diagram with defect states below the conduction band of each phase, which facilitated visible-light activity and easy transfer of charge carriers from one phase to another. Our study showed that the well-designed multiphase construction with oxygen vacancies enhanced the photocatalytic activity tremendously owing to the presence of a higher number of phase junctions.

10acharge transfer10aDefects10aHydrogenation10atitania10awater splitting1 aPreethi, Laguduva, K.1 aMathews, Tom1 aWalczak, Lukasz1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/marginally-hydrogenated-triphasic-titania-nanotubes-effective-visible-light-photocatalytic04103nas a2200205 4500008004100000245012200041210006900163260000800232300001600240490000700256520332100263100002903584700001903613700002303632700002403655700002603679700003303705700003003738856012903768 2019 eng d00a Molybdenum carbide catalyst for the reduction of CO2 to CO: surface science aspects by NAPPES and catalysis studies 0 aMolybdenum carbide catalyst for the reduction of CO2 to CO surfa cAUG a12199-122090 v483 a

Carbon dioxide is a greenhouse gas, and needs to be converted into one of the useful feedstocks, such as carbon monoxide and methanol. We demonstrate the reduction of CO2 with H-2 as a reducing agent, via a reverse water gas shift (RWGS) reaction, by using a potential and low cost Mo2C catalyst. Mo2C was evaluated for CO2 hydrogenation at ambient pressure as a function of temperature, and CO2 : H-2 ratio at a gas hourly space velocity (GHSV) of 20 000 h(-1). It is demonstrated that the Mo2C catalyst with 1 : 3 ratio of CO2 : H-2 is highly active (58% CO2 conversion) and selective (62%) towards CO at 723 K at ambient pressure. Both properties (basicity and redox properties) and high catalytic activity observed with Mo2C around 700 K correlate well and indicate a strong synergy among them towards CO2 activation. X-ray diffraction and Raman analysis show that the Mo2C catalyst remains in the beta-Mo2C form before and after the reaction. The mechanistic aspects of the RWGS reaction were determined by near-ambient pressure X-ray photoelectron spectroscopy (NAPXPS) with in situ generated Mo2C from carburization of Mo-metal foil. NAPXPS measurements were carried out at near ambient pressure (0.1 mbar) and various temperatures. Throughout the reaction, no significant changes in the Mo2+ oxidation state (of Mo2C) were observed indicating that the catalyst is highly stable; C and O 1s spectral results indicate the oxycarbide species as an active intermediate for RWGS. A good correlation is observed between catalytic activity from atmospheric pressure reactors and the electronic structure details derived from NAPXPS results, which establishes the structure-activity correlation.

1 aReddy, Kasala, Prabhakar1 aDama, Srikanth1 aMhamane, Nitin, B.1 aGhosalya, Manoj, K.1 aRaja, Thirumalaiswamy1 aSatyanarayana, Chilukuri, V.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/molybdenum-carbide-catalyst-reduction-co2-co-surface-science-aspects-nappes-and-catalysis02249nas a2200157 4500008004100000022001400041245008400055210006900139260000900208300001400217490000700231520169300238100001601931700003001947856011401977 2019 eng d a1477-922600aMorphology-dependent, green, and selective catalytic styrene oxidation on Co3O40 aMorphologydependent green and selective catalytic styrene oxidat cAPR  a4574-45810 v483 a

Despite the great successes in the controlled fabrication of nanomaterials with specific composition and morphology, it is still challenging to have the desired control on the defect sites of catalyst materials. For unfolding the mystery of this aspect, catalytic styrene epoxidation was attempted on spinel Co3O4 with two different morphologies, namely, SNR (nanorods prepared by the solvothermal method with the (110) facet), HNR (nanorods prepared by the hydrothermal methodwith the (111) facet) and NC (nanocubes with the (110) facet) were synthesized and subjected to olefin oxidation with O-2. Even without any catalyst pretreatment, all three Co3O4 catalyst systems were found to be active for selective epoxidation of styrene with O-2 at ambient pressure in the liquid phase. The correlation between catalytic activity and selectivity trend suggests that the reaction is highly structure-sensitive and facile on the (110) facet. Temperature-dependent near ambient pressure X-ray photoelectron spectroscopy (NAPXPS) was carried out at 0.1 mbar O-2 pressure to understand the mechanistic aspects. The distinct catalytic activity of NC (110) and SNR (110) can be attributed to the population of defect sites on the catalyst surface. NC morphology with comparatively fewer defect sites shows high activity and selectivity, suggesting that styrene oxidation on Co3O4 is structure-sensitive; however, unlike metal surfaces, fewer defects are more favourable for catalytic styrene epoxidation due to facile adsorption and activation of the substrate and O-2 on Co3+ sites. The present investigations suggest that surface defects need not necessarily increase catalytic activity.

1 aJain, Ruchi1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/morphology-dependent-green-and-selective-catalytic-styrene-oxidation-co3o402217nas a2200253 4500008004100000022001400041245010200055210006900157260000800226490000700234520136300241653002201604653001901626653001901645653002101664653002001685100002101705700002301726700001501749700002201764700001901786700003001805856012801835 2025 eng d a1861-472800aMesoporous Fe2O3-TiO2 integrated with plasmonic Ag nanoparticles for enhanced solar H2 production0 aMesoporous Fe2O3TiO2 integrated with plasmonic Ag nanoparticles  cMAY0 v203 a

Present work describes a sol-gel assisted one-pot synthesis of mesoporous Fe2O3-TiO2 nanocomposites (TiFe) with different Ti : Fe ratios, and fabrication of Ag-integrated with TiFe nanocomposites (TiFeAg) by a chemical reduction method and demonstrated for high solar H2 generation activity in direct sunlight. Enhanced solar H2 production is attributed to the light absorption from entire UV+Visible region of solar spectrum combined with Schottky (Ag-semiconductor) and heterojunctions (TiO2-Fe2O3), as evidenced from HRTEM and various characterization studies. TiFeAg-2 thin film (1 wt % Ag-loaded TiFe-4) displayed the highest activity with a solar H2 yield of 7.64 mmol h-1g-1, which is 48 times higher than that of bare TiO2 and 5 times higher in thin film form compared to its powder counterpart. Schottky and heterojunctions formed at the interface efficiently separate the charge carriers and increase the hydrogen production activity. The highest H2 production activity of TiFeAg-2 is partly attributed to the heterogeneous distribution of Fe3+ and metallic Ag-species with relatively high Ag/Ti surface atomic ratio. A plausible photocatalytic reaction mechanism on TiFeAg nanocomposite may involve the direct electron transfer from both Fe2O3 and TiO2 to Ag nanoparticles which are subsequently utilized for the reduction of H+ to H2.

10aenergy conversion10agreen hydrogen10aPhotocatalysis10aSolar harvesting10awater splitting1 aMani, Sunesh, S.1 aRajendran, Sivaraj1 aSaju, Simi1 aBabu, Bindhya, M.1 aMathew, Thomas1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mesoporous-fe2o3-tio2-integrated-plasmonic-ag-nanoparticles-enhanced-solar-h2-production02816nas a2200241 4500008004100000022001400041245014600055210006900201260000800270300001400278490000700292520194900299100002302248700001502271700002102286700002902307700001802336700002402354700001802378700001902396700003002415856012902445 2025 eng d a2050-748800aMultifunctional NiO/Ti3+-TiO2 for concurrent water reduction and glycerol oxidation to value added products by sunlight driven photocatalysis0 aMultifunctional NiOTi3TiO2 for concurrent water reduction and gl cJAN a2105-21200 v133 a

The present work describes the synthesis of bifunctional-mesoporous-self-doped Ti3+ containing NiO/TiO2 photocatalysts for concurrent utilization of e- and h+ to produce H2 and value-added products (VAPs), respectively, from aqueous glycerol. UV-vis diffuse reflectance results and band gap analysis revealed an improved light absorption due to integration of Ni2+ with Ti3+/TiO2. Various electrochemical, PL and TRPL spectral analyses demonstrate p-n heterojunction formation between NiO and Ti3+-TiO2, which enhances charge separation and helps in achieving improved activity. HRTEM analysis of NiO/Ti3+-TiO2 nanocomposites revealed that NiO is highly dispersed on TiO2 with interfacial heterojunctions between them. XPS results demonstrate the partial reduction of Ti4+ to Ti3+ and Ni-Ti synergetic interaction in NiO/TiO2 to form NiO/Ti3+-TiO2 nanocomposites. EXAFS studies show that the Ni-O bond distance is similar to that of NiTiO3 suggesting electronic integration of components of the photocatalyst by forming a Ni2+-O-Ti3+/Ti4+ lattice network. Ni2+/Ti3+-TiO2 nanocomposites as a bifunctional photocatalyst exhibited significantly enhanced activity in H2 production and conversion of glycerol to VAPs, namely, glycolaldehyde, 1,3-dihydroxyacetone, and formic acid; formation of these products highlights not only oxidation, but also C-C cleavage of glycerol. The NiO/Ti3+-TiO2 photocatalysts fabricated in thin film form displayed higher photocatalytic efficiency than their powder counterpart. Among NiO/Ti3+-TiO2 nanocomposites NiT-3 exhibits the highest H2 yield at 15.62 mmol h-1 g-1, which is 38 times higher than that of bare TiO2. The enhanced photocatalytic activity is ascribed to the high charge carrier density, the synergistic interaction between Ni2+ and Ti3+-TiO2, formation of a p-n heterojunction at the interface between NiO and Ti3+-TiO2 and effective utilization of charge carriers for redox reactions.

1 aRajendran, Sivaraj1 aSaju, Simi1 aMani, Sunesh, S.1 aAsoka, Anantha, Krishnan1 aSaha, Arindam1 aArun, Pushkaran, S.1 aGhosh, Biplab1 aMathew, Thomas1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/multifunctional-nioti3-tio2-concurrent-water-reduction-and-glycerol-oxidation-value-added19043nas a2200229 45000080041000002450148000412100071001892600008002603000014002684900007002825201819000289100002318479700001518502700002118517700002918538700001818567700002418585700001818609700001918627700003018646856013718676 2025 eng d00aMultifunctional NiO/Ti3+–TiO2 for concurrent water reduction and glycerol oxidation to value added products by sunlight driven photocatalysis0 aMultifunctional NiOTi3–TiO2 for concurrent water reduction and g cJAN a2105-21200 v133 a

The present work describes the synthesis of bifunctional-mesoporous-self-doped Ti3+ containing NiO/TiO2 photocatalysts for concurrent utilization of e and h+ to produce H2 and value-added products (VAPs), respectively, from aqueous glycerol. UV-vis diffuse reflectance results and band gap analysis revealed an improved light absorption due to integration of Ni2+ with Ti3+/TiO2. Various electrochemical, PL and TRPL spectral analyses demonstrate p–n heterojunction formation between NiO and Ti3+–TiO2, which enhances charge separation and helps in achieving improved activity. HRTEM analysis of NiO/Ti3+–TiO2 nanocomposites revealed that NiO is highly dispersed on TiO2 with interfacial heterojunctions between them. XPS results demonstrate the partial reduction of Ti4+ to Ti3+ and Ni–Ti synergetic interaction in NiO/TiO2 to form NiO/Ti3+–TiO2 nanocomposites. EXAFS studies show that the Ni–O bond distance is similar to that of NiTiO3 suggesting electronic integration of components of the photocatalyst by forming a Ni2+–O–Ti3+/Ti4+ lattice network. Ni2+/Ti3+–TiO2 nanocomposites as a bifunctional photocatalyst exhibited significantly enhanced activity in H2 production and conversion of glycerol to VAPs, namely, glycolaldehyde, 1,3-dihydroxyacetone, and formic acid; formation of these products highlights not only oxidation, but also C–C cleavage of glycerol. The NiO/Ti3+–TiO2 photocatalysts fabricated in thin film form displayed higher photocatalytic efficiency than their powder counterpart. Among NiO/Ti3+–TiO2 nanocomposites NiT-3 exhibits the highest H2 yield at 15.62 mmol h−1 g−1, which is 38 times higher than that of bare TiO2. The enhanced photocatalytic activity is ascribed to the high charge carrier density, the synergistic interaction between Ni2+ and Ti3+–TiO2, formation of a p–n heterojunction at the interface between NiO and Ti3+–TiO2 and effective utilization of charge carriers for redox reactions.

1 aRajendran, Sivaraj1 aSaju, Simi1 aMani, Sunesh, S.1 aAsoka, Anantha, Krishnan1 aSaha, Arindam1 aArun, Pushkaran, S.1 aGhosh, Biplab1 aMathew, Thomas1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/multifunctional-nioti3%E2%80%93tio2-concurrent-water-reduction-and-glycerol-oxidation-value-added02691nas a2200241 4500008004100000022001400041245015900055210006900214260000800283300001200291490000800303520180200311653003002113653001902143653001902162653003402181653001402215653001202229100002902241700003002270700002202300856012702322 2025 eng d a0360-319900aMultiphasic heterojunctions: a strategic approach to enhance the charge transfer dynamics of titania for superior solar photocatalytic hydrogen production0 aMultiphasic heterojunctions a strategic approach to enhance the  cMAR a133-1460 v1133 a

Multiphasic titania has been prepared to study the role of multiple heterojunctions on the charge transfer dynamics and resultant photocatalytic hydrogen production. Through an acid regulated hydrothermal method, four materials with following phase compositions were prepared viz. single phase anatase and rutile, biphasic anatase-rutile and triphasic anatase-brookite-rutile. The phase compositions of the materials were confirmed through XRD and HRTEM studies. The biphasic and triphasic materials were found to be highly nanoparticulate in nature while forming numerous and diverse heterojunctions. In the triphasic material, various binary and ternary heterojunctions were observed. These heterojunctions performed in harmony to ensure efficient charge transport as shown by the low charge transfer resistance and high electron lifetime. This subsequently ensured a high reduction capability and photocurrent response. This all culminated into the triphasic material outperforming all other materials in solar photocatalytic hydrogen production. The H2 yield from the triphasic material was 81% and 40% higher than the pristine anatase and the biphasic material respectively. Additionally, by using the triphasic material in thin film form, a 4-fold increase in the hydrogen yield with a high apparent quantum efficiency of 8.2 % was achieved over the particulate form. The superior charge transport and photocurrent response due to the greater varied heterojunction formation in the anatase-rutile-brookite material as opposed to that in the biphasic material led to this superior performance. Thus, multiple heterojunctions, in this case, a triphasic heterojunction of anatase, rutile and brookite phases opens up a new avenue of research for efficient green hydrogen production.

10aGreen hydrogen production10aheterojunction10aPhotocatalysis10aPhotoelectrochemical analysis10athin film10atitania1 aNingthoukhongjam, Pujita1 aGopinath, Chinnakonda, S.1 aNair, Ranjith, G. uhttps://library.ncl.res.in/content/multiphasic-heterojunctions-strategic-approach-enhance-charge-transfer-dynamics-titania