02416nas a2200217 4500008004100000022001400041245009900055210006900154260000800223300001200231490000700243520166800250653002701918653001901945653002101964653001901985653002002004100002202024700003002046856012202076 2018 eng d a0360-319900aPt - g-C3N4 - (Au/TiO2): electronically integrated nanocomposite for solar hydrogen generation0 aPt gC3N4 AuTiO2 electronically integrated nanocomposite for sola cJAN a601-6130 v433 a

A potential nanocomposite photocatalyst was designed by integrating Pt nanoclusters (co catalyst and electron sink) with graphitic carbon nitride (g-C3N4 (gcn)) (charge diffusion) and 0.5 wt % Au containing Au-TiO2 (AuT) (plasmonic on semiconductor) for solar water splitting (SWS). Variety of Pt-gcn-AuTiO2 compositions has been evaluated for SWS under one sun conditions. Complexity of the photocatalyst was increased systematically from Au-TiO2, gcn-TiO2 to Pt-gcn-Au-TiO2 to explore the influence of different combinations. Electronic integration of charge separation/diffusion component (gcn) with light absorbing sensitizer components (Au and gcn), and co-catalyst (Pt) seems to be the critical factor to improve hydrogen yield (HY) or overall efficiency. Although addition of gcn increase the HY of composites, there is no SWS activity observed on bare TiO2 or gcn. Au or Pt on gcn enhances the charge separation effectively and interface between Au and/or Pt with gcn works as the Schottky barrier. A monodispersion of Au over TiO2 and Pt nanoclusters over gcn/AuTiO2 composite lead to the maximum solar hydrogen yield (1.52 mmol/h g) with an apparent quantum yield (AQY) of 7.5%. Photoelectron and photoluminescence spectral studies confirm the electron transfer from Au to gcn, and Au and/or gcn to titania. A thorough physico-chemical investigation of various composites underscores the electronic integration aspects of the nanocomposite towards storage of electrons in the Pt co-catalyst and hence an effective charge separation and an increase in AQY. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

10aElectronic integration10aPhotocatalysis10aSchottky barrier10aSolar hydrogen10awater splitting1 aDevaraji, Perumal1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/pt-g-c3n4-autio2-electronically-integrated-nanocomposite-solar-hydrogen-generation01969nas a2200265 4500008004100000022001400041245014300055210006900198260000900267300001600276490000700292520103800299653002001337653001801357653001901375653001301394653001901407100002101426700002801447700001701475700002101492700002901513700003001542856013101572 2020 eng d a1944-824400aCan half-a-monolayer of pt simulate activity like that of bulk pt? solar hydrogen activity demonstration with quasi-artificial leaf device0 aCan halfamonolayer of pt simulate activity like that of bulk pt  cJUL  a30420-304300 v123 a

Pt is the best cocatalyst for hydrogen production. It is also well-known that the surface atomic layer is critical for catalysis. To minimize the Pt content as cocatalyst, herein we report on half-a-monolayer of Pt (0.5 theta(Pt)) decorated on earth-abundant Ni-Cu cocatalyst, which is integrated with a quasiartificial leaf (QuAL) device (TiO2/ZnS/CdS) and demonstrated for efficient solar hydrogen production. For the QuAL, TiO2 is sensitized with ZnS and CdS quantum dots by the SILAR method. The 0.5 theta(Pt)-decorated Ni-Cu shows an onset potential of 0.05 V vs reversible hydrogen electrode for the hydrogen evolution reaction, which is almost similar to that of commercial Pt/C. Photoactivity of the present QuAL device with either bulk Pt or 0.5 theta(Pt)-coated Ni-Cu cocatalyst is, surprisingly, equal. Our findings underscore that a fraction of a monolayer of Pt can enhance the activity of the cocatalyst, and it is worth exploring further for the high activity associated with atomic Pt and other noble metals.

10aartificial leaf10anickel-copper10aPhotocatalysis10aplatinum10aSolar hydrogen1 aBajpai, Himanshu1 aPatra, Kshirodra, Kumar1 aRanjan, Ravi1 aNalajala, Naresh1 aReddy, Kasala, Prabhakar1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/can-half-monolayer-pt-simulate-activity-bulk-pt-solar-hydrogen-activity-demonstration-quasi01936nas a2200265 4500008004100000022001400041245013300055210006900188260000800257300001200265490000700277520102200284653002801306653002001334653001901354653001101373653002801384653001901412100002101431700002301452700002101475700001901496700003001515856012501545 2021 eng d a2194-428800aElectronically integrated mesoporous Ag-TiO2 nanocomposite thin films for efficient solar hydrogen production in direct sunlight0 aElectronically integrated mesoporous AgTiO2 nanocomposite thin f cAUG a21003560 v103 a

The synthesis of mesoporous TiO2 by a solution-based assembly process and Ag/TiO2 nanocomposites is provided. The efficacy of Ag/TiO2 nanocomposite as photocatalyst in thin-film form is demonstrated for solar hydrogen generation in sunlight. Integration of Ag with TiO2 dramatically enhanced the H-2 production: with 1 wt% Ag on TiO2 (TiAg-1), the H-2 yield was observed to be 4.59 mmol h(-1) g(-1), which is 2.3 (30) times larger than 0.5 wt% Ag on TiO2. TiAg-1 shows 4.3 times higher activity in film form compared with its powder counterpart. High photocatalytic efficiency is attributed to the surface plasmon resonance effect of Ag, electronic integration of Ag with TiO2, and subsequent valence band broadening, large distribution of Ag nanoparticles and abundant Ag-TiO2 Schottky junctions, and the later minimizes electron-hole recombination. Interparticle mesoporous network increases necking and the high surface area offers easy accessibility of the reactants to a large number of active sites.

10aheterogeneous catalysis10aheterojunctions10aplasmon effect10aSilver10asolar energy conversion10aSolar hydrogen1 aMani, Sunesh, S.1 aRajendran, Sivaraj1 aNalajala, Naresh1 aMathew, Thomas1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/electronically-integrated-mesoporous-ag-tio2-nanocomposite-thin-films-efficient-solar03098nas a2200277 4500008004100000022001400041245012600055210006900181260000900250300001200259490000600271520215500277653001902432653001902451653001902470653001402489653001202503100002302515700002102538700002902559700002902588700002402617700001902641700003002660856013002690 2023 eng d a2574-096200aFacile one-pot synthesis of Cu x O/TiO2 photocatalysts by regulating Cu oxidation state for efficient solar H2 production0 aFacile onepot synthesis of Cu x OTiO2 photocatalysts by regulati cDEC  a104-1160 v73 a

Development of highly efficient CuxO/TiO2 photocatalysts by regulating the oxidation state of Cu exclusively in either single or mixed oxidation state(s) is desirable but difficult to achieve without employing any external reagents. The present work describes a one-pot synthesis strategy to obtain CuxO/TiO2 photocatalysts with Cu in +1 and/or +2 by using a suitable combination of ethylene diamine tetra acetic acid (EDTA) and ethylene diamine, carefully varying the Cu content, and heat treatment process. CuxO/TiO2 nanocomposite catalysts were characterized thoroughly by physicochemical methods. Textural analysis indicates a high dispersion of CuxO on porous TiO2 with p-n heterojunctions between them in CuxO/TiO2 catalysts. UV-visible spectral analysis suggests the presence of CuxO on TiO2 with significantly extended absorption from the UV to the visible region. X-ray photoelectron spectroscopy (XPS) analysis indicates a strong synergetic interaction between TiO2 and CuxO due to the comparable CB potential and p-n heterojunction at the interface among them. Photoelectrochemical studies demonstrate excellent charge-carrier separation efficiency, low charge-transfer resistance, and high double-layer capacitance with Cu2O/TiO2 photocatalysts. Photocatalytic efficacy of a CuxO/TiO2 nanocomposite in thin-film form has been demonstrated for solar hydrogen generation in sunlight. The incorporation of Cu+ in TiO2 largely improves the H-2 production, and all of the CuxO/TiO2 nanocomposites in thin-film form exhibited higher efficiency compared to their particulate/suspension counterpart. Among the composite catalysts, TiCu-1 in thin-film form, with Cu exclusively in +1 oxidation state, exhibited a high hydrogen production rate of 7.06 mmol/hg, which is 6 times higher than its suspension counterpart; also catalysts containing mixed Cu-oxidation states exhibited about 60-70% activity as that of TiCu-1. The superior performance of Cu2O/TiO2 nanocomposites in thin-film form was due to their enhanced light harvesting ability, high mass transfer rate, and easy accessibility of the reactant species to the active sites.

10aheterojunction10aPhotocatalysis10aSolar hydrogen10athin film10atitania1 aRajendran, Sivaraj1 aMani, Sunesh, S.1 aNivedhitha, Thazhath, R.1 aAsoka, Anantha, Krishnan1 aArun, Pushkaran, S.1 aMathew, Thomas1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/facile-one-pot-synthesis-cu-x-otio2-photocatalysts-regulating-cu-oxidation-state-efficient