02821nas a2200253 4500008004100000022001400041245010600055210006900161260000800230300001600238490000700254520197500261653001202236653001902248653003002267653000902297653002002306100001602326700002102342700002202363700002002385700003002405856013202435 2019 eng d a1944-824400aElectronic integration and thin film aspects of Au-Pd/rGO/TiO2 for improved solar hydrogen generation0 aElectronic integration and thin film aspects of AuPdrGOTiO2 for  cSEP a32869-328780 v113 a

In the present work, we have synthesized noble bimetallic nanoparticles (Au-Pd NPs) on a carbon-based support and integrated with titania to obtain Au-Pd/C/TiO2 and Au-Pd/rGO/TiO2 nanocomposites using an ecofriendly hydrothermal method. Here, a 1:1 (w/w) Au-Pd bimetallic composition was dispersed on (a) high-surface-area (3000 m(2) g(-1)) activated carbon (Au-Pd/C), prepared from a locally available plant source (in Assam, India), and (b) reduced graphene oxide (rGO) (Au-Pd/rGO); subsequently, they were integrated with TiO2. The shift observed in Raman spectroscopy demonstrates the electronic integration of the bimetal with titania. The photocatalytic activity of the above materials for the hydrogen evolution reaction was studied under 1 sun conditions using methanol as a sacrificial agent in a powder form. The photocatalysts were also employed to prepare a thin film by the drop-casting method. Au-Pd/rGO/TiO2 exhibits 43 times higher hydrogen (H-2) yield in the thin film form (21.50 mmol h(-1) g(-1)) compared to the powder form (0.50 mmol h(-1) g(-1)). On the other hand, Au-Pd/C/TiO2 shows 13 times higher hydrogen (H-2) yield in the thin film form (6.42 mmol h(-1) g(-1)) compared to the powder form (0.48 mmol h(-1) g(-1)). While powder forms of both catalysts show comparable activity, the Au-Pd/rGO/TiO2 thin film shows 3.4 times higher activity than that of Au-Pd/C/TiO2. This can be ascribed to (a) an effective separation of photogenerated electron-hole pairs at the interface of Au-Pd/rGO/TiO2 and (b) the better field effect due to plasmon resonance of the bimetal in the thin film form. The catalytic influence of the carbon-based support is highly pronounced due to synergistic binding interaction of bimetallic nanoparticles. Further, a large amount of hydrogen evolution in the film form with both catalysts (Au-Pd/C/TiO2 and Au-Pd/rGO/TiO2) reiterates that charge utilization should be better compared to that in powder catalysts.

10abimetal10aPhotocatalysis10asurface plasmon resonance10aTiO210awater splitting1 aTudu, Bijoy1 aNalajala, Naresh1 aReddy, Kasala, P.1 aSaikia, Pranjal1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/electronic-integration-and-thin-film-aspects-au-pdrgotio2-improved-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-quasi01740nas a2200241 4500008004100000022001400041245008300055210006900138260000800207300001200215490000600227520098000233653001301213653002201226653001301248653001901261653001701280100001601297700002101313700002001334700003001354856011401384 2020 eng d a2367-198X00aCu-Ni bimetal integrated TiO2 thin film for enhanced solar hydrogen generation0 aCuNi bimetal integrated TiO2 thin film for enhanced solar hydrog cMAY a19005570 v43 a

A series of non-noble Cu-Ni bimetallic catalysts is prepared with different molar proportions of metals. Of these bimetallic catalysts, 1 wt% is subsequently integrated with titania P25. The catalysts are evaluated for solar hydrogen generation under 1 sun condition in both the powder and thin film forms. All the photocatalysts in the thin film exhibit an 8-24 times higher hydrogen yield (HY) compared with the corresponding particulate counterpart. The highest HY (41.7 mmol h(-1) g(-1)) is demonstrated for the photocatalyst Cu-Ni/TiO2 (CNT; 1:1 = Cu:Ni) in the thin film form, which is 24 times higher than that with its powder counterpart (1.75 mmol h(-1) g(-1)) and exceeds the performance of other Cu-Ni/TiO2 compositions. This enhanced activity in the thin film can be ascribed to improved absorption of visible light and an effective separation of photogenerated charge carriers at the interface of Cu-Ni/TiO2 leading to better charge carrier utilization.

10abimetals10aenergy conversion10aHydrogen10aPhotocatalysis10asolar energy1 aTudu, Bijoy1 aNalajala, Naresh1 aSaikia, Pranjal1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/cu-ni-bimetal-integrated-tio2-thin-film-enhanced-solar-hydrogen-generation02461nas a2200253 4500008004100000022001400041245017300055210006900228260000900297300001600306490000600322520151900328653002801847653001801875653001401893653001901907653002501926100002101951700002701972700002301999700002502022700003002047856013002077 2021 eng d a2574-096200aAqueous methanol to formaldehyde and hydrogen on Pd/TiO2 by photocatalysis in direct sunlight: structure dependent activity of nano-Pd and atomic Pt-coated counterparts0 aAqueous methanol to formaldehyde and hydrogen on PdTiO2 by photo cNOV  a13347-133600 v43 aIn the present investigation, facet-controlled Pd nanoparticles with nanocube (Pd-NC) and truncated octahedron (Pd-TO) morphologies, and their counterparts with half-a-monolayer of atomic Pt coated (0.5 theta(Pt)-Pd-NC and 0.5 theta(Pt)-Pd-TO) surfaces were prepared. All of them were characterized and evaluated as cocatalyst after supporting them on commercial titania (P25) (Pd-NC/P25, Pd-TO/P25, 0.5 theta(Pt)-Pd-NC/P25, and 0.5 theta(Pt)-Pd-TO/P25) under direct sunlight and/or one sun conditions for the oxidation of methanol to formaldehyde along with solar hydrogen production. Pd-NC/P25 shows higher activity for hydrogen generation compared to Pd-TO/P25; however, activity reversal occurs with the above cocatalysts, but, after Pt-coating with further enhanced activity. The highest conversion of methanol (0.2 mu mol/h.mg) to 100% selective formaldehyde was observed with 0.5 theta(Pt)-Pd-TO/P25, while other catalysts show significantly lower methanol conversion in the following order: 0.5 theta(Pt)-Pd-TO/P25 > 0.5 theta(Pt)-Pd-NC/P25 > Pd-NC/P25 > Pd-TO/P25. Pt-coated on (111) facets of Pd-TO simulates the activity associated as that of Pt(111) facets and demonstrating the highest and facet dependent activity. The present study is truly in resonance with exploiting the surface properties for heterogeneous catalysis, and highlights that less than a monolayer of Pt is sufficient to simulate the activity as that of bulk Pt. It is worth exploring this concept to other metals and substrates too.10aheterogeneous catalysis10aNanomaterials10aOxidation10aPhotocatalysis10asurface modification1 aNalajala, Naresh1 aSalgaonkar, Kranti, N.1 aChauhan, Inderjeet1 aMekala, Siva, Prasad1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/aqueous-methanol-formaldehyde-and-hydrogen-pdtio2-photocatalysis-direct-sunlight-structure01482nas a2200277 4500008004100000022001400041245012100055210006900176260000800245300001200253490000700265520056300272653001000835653001400845653001900859653002000878100002400898700002000922700001900942700001700961700002000978700002100998700003001019700002301049856013201072 2023 eng d a0909-049500aPhotocatalytic setup for in situ and operando ambient-pressure X-ray photoelectron spectroscopy at MAX IV Laboratory0 aPhotocatalytic setup for in situ and operando ambientpressure Xr cMAY a613-6190 v303 a

The Ambient-Pressure X-ray Photoelectron Spectroscopy (APXPS) endstation at the SPECIES beamline at MAX IV Laboratory has been improved. The latest upgrades help in performing photo-assisted experiments under operando conditions in the mbar pressure range using gas and vapour mixtures whilst also reducing beam damage to the sample caused by X-ray irradiation. This article reports on endstation upgrades for APXPS and examples of scientific cases of in situ photocatalysis, photoreduction and photo-assisted atomic layer deposition (photo-ALD).

10aAPXPS10aphoto-ALD10aPhotocatalysis10asolar simulator1 aKlyushin, Alexander1 aGhosalya, Manoj1 aKokkonen, Esko1 aEads, Calley1 aJones, Rosemary1 aNalajala, Naresh1 aGopinath, Chinnakonda, S.1 aUrpelainen, Samuli uhttps://library.ncl.res.in/content/photocatalytic-setup-situ-and-operando-ambient-pressure-x-ray-photoelectron-spectroscopy-max02213nas a2200241 4500008004100000022001400041245018400055210006900239260000800308490000700316520131500323653002201638653001801660653001401678653001901692653001901711100002701730700002101757700002101778700002001799700003001819856012201849 2023 eng d a1861-472800aSelective and generic photocatalytic oxidation of alcohol with Pd-TiO2 thin films: butanols to butanal/butanone with different morphologies of Pd and 0.5 theta(Pt)-Pd counterparts0 aSelective and generic photocatalytic oxidation of alcohol with P cMAR0 v183 a

The present study reports on the photocatalytic oxidation of butanols to butanal/butanone using thin film form of facet-dependent nano-Pd supported on commercial TiO2 under one-sun condition and demonstrates the generic nature. Pd-nanocube (Pd-NC(100)), Pd-truncated octahedron (Pd-TO (100) and (111)), polycrystalline (Pd-PC), and their counterparts with half-a-monolayer Pt-coated on Pd (0.5 theta(Pt)-Pd)) have been used as co-catalyst. A potentially scalable thin film form of Pd/TiO2 photocatalyst, prepared by drop-casting method, has been employed to study oxidation of n-butanol, 2-butanol, and iso-butanol to corresponding aldehyde/ketone. 100% selectivity is demonstrated to respective aldehyde/ketone with any catalyst used in the present study with varying degree of butanols conversion by NMR. 0.5 theta(Pt)-Pd-TO/TiO2 shows the highest conversion of 2-butanol to butanone (13.6% in 4 h). Continuous 10 h of reaction with the most active 0.5 theta(Pt)-Pd-TO/P25 catalyst demonstrates 31% conversion of 2-butanol to butanone, and catalyst recyclability has been demonstrated. The present protocol can be scalable to large scales to maximize the conversion in direct sunlight. Due to its generic nature, the current method can also be applied to many other alcohols and substrate molecules.

10aenergy conversion10aNanomaterials10aOxidation10aPhotocatalysis10aSustainability1 aSalgaonkar, Kranti, N.1 aKale, Sandip, R.1 aNalajala, Naresh1 aMansuri, Sayana1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/selective-and-generic-photocatalytic-oxidation-alcohol-pd-tio2-thin-films-butanols