02460nas a2200253 4500008004100000022001400041245017300055210006900228260000900297300001600306490000600322520151900328653002801847653001801875653001401893653001901907653002501926100002101951700002701972700002301999700002502022700003002047856012902077 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. uhttp://library.ncl.res.in/content/aqueous-methanol-formaldehyde-and-hydrogen-pdtio2-photocatalysis-direct-sunlight-structure02916nas a2200229 4500008004100000022001400041245015400055210006900209260000900278300001600287490000700303520206700310100002702377700002102404700002302425700002102448700002302469700002002492700001802512700003002530856012602560 2023 eng d a2050-748800aBaby step in assembling and integrating the components of an artificial photosynthesis device with forced heterojunctions towards improved efficiency0 aBaby step in assembling and integrating the components of an art cJUL  a15168-151820 v113 a

How to achieve unassisted, economical, scalable, and sustainable artificial photosynthesis for liquid fuels/products with improved solar-to-fuel efficiency (STFE) to address a carbon-neutral economy remains a big question. To a large degree, the extent of charge separation at heterojunction interfaces and charge utilization determine the STFE. Towards this, BiVO3 is assembled from ionic-precursors into TiO2 pores, and integrated structurally and electronically with TiO2 on calcination as BiVO4 quantum dots (BVQDs). BVQDs in TiO2 (BVT) pores lead to an all-inorganic system with a sub-quadrillion number of heterojunctions in a 1 cm(2) device (contains similar to 25 mu g of BiVO4 (similar to 2.5 wt%) in the nanopores of similar to 975 mu g of TiO2 (similar to 97.5 wt%)) and facilitate artificial photosynthesis. We demonstrate 31-38% STFE with a photon to chemical conversion turn over frequency (ToF(P2C)) of 2.73 s(-1) with a 1 cm(2) wireless BiVO4-TiO2 artificial leaf (BVT-AL) device for HCHO and CH3OH. The sequential nature of CO2 reduction to HCHO and then to CH3OH is evident from the reaction results. (CO2)-C-13 isotopic labeling experiments confirm that the input CO2 is the source for product formation. A large increase in the photocurrent density and incident photon-to-current efficiency (IPCE) of BVT, over 100% for the BiVO4 photoanode in visible light, demonstrates and supports efficient visible light absorption, charge separation and migration to the redox sites. A device has been demonstrated to show sustainable activity in direct sunlight, and addresses scalability from 1 to 9 cm(2). Assuming no change (50% decrease) in the STFE, a 6.74 m(2) device is expected to convert 1 (0.5) kg h(-1) CO2 into C1-oxygenates in sunlight. DFT calculations carried out with anatase TiO2 (101) and BiVO4 (121) interfaces support many of the experimental findings, including electron flow from the latter to the former, and interaction of the oxygen of TiO2 with BiVO4 and vice versa at the interface towards forced heterojunctions.

1 aSalgaonkar, Kranti, N.1 aBajpai, Himanshu1 aMhamane, Nitin, B.1 aNalajala, Naresh1 aChauhan, Inderjeet1 aThakkar, Kavita1 aJoshi, Kavita1 aGopinath, Chinnakonda, S. uhttp://library.ncl.res.in/content/baby-step-assembling-and-integrating-components-artificial-photosynthesis-device-forced02216nas a2200205 4500008004100000022001400041245012900055210006900184260000800253300001400261490000700275520145200282100002301734700002801757700002101785700002301806700002701829700003001856856012401886 2023 eng d a1477-922600aNanostructured Co-doped BiVO4 for efficient and sustainable photoelectrochemical chlorine evolution from simulated sea-water0 aNanostructured Codoped BiVO4 for efficient and sustainable photo cFEB a2051-20610 v523 a

The co-production of hydrogen and chlorine from sea-water splitting could be a potential, sustainable and attractive route by any method. However, challenges to overcome are many, and critically, the sustainability and operating potential of the electrocatalyst are important. In this work, we report on Co-doping in the BiVO4 (Co-BV) crystal lattice and employed the same as the photoanode; Co-BV exhibits a photocurrent of 190 mu A cm(-2) at 1.1 V vs. RHE (the reversible hydrogen electrode) in the acidic sodium chloride solution (pH 2.3) under one sun illumination. The best-performing photoanode, with 0.05 mol% of Co doping (0.05 Co-BV), selectively produced active chlorine with 92% faradaic efficiency at 1.1 V vs. RHE by successfully suppressing the kinetically sluggish oxygen evolution reaction (OER) and the stability of the catalyst was demonstrated for up to 20 h. This is the lowest operating potential reported for the chlorine evolution reaction (CER), thus far. The overpotential required for CER with 0.05 Co-BV is lower than that of OER, which leads to selective CER at 1.1 V (vs. RHE). Co-doping into the BiVO4 lattice decreases the charge transfer resistance and enhances the CER kinetics due to its structural and electronic integration with the BV lattice. We demonstrate that Co-doping also improves the lifetime of the charge carrier and enhances the current density of CER and sustainability of the catalyst.

1 aChauhan, Inderjeet1 aPatra, Kshirodra, Kumar1 aBajpai, Himanshu1 aMhamane, Nitin, B.1 aSalgaonkar, Kranti, N.1 aGopinath, Chinnakonda, S. uhttp://library.ncl.res.in/content/nanostructured-co-doped-bivo4-efficient-and-sustainable-photoelectrochemical-chlorine02212nas a2200241 4500008004100000022001400041245018400055210006900239260000800308490000700316520131500323653002201638653001801660653001401678653001901692653001901711100002701730700002101757700002101778700002001799700003001819856012101849 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. uhttp://library.ncl.res.in/content/selective-and-generic-photocatalytic-oxidation-alcohol-pd-tio2-thin-films-butanols05783nas a2200325 4500008004100000245013700041210006900178260000800247300001400255490000600269520469500275100002204970700002304992700002005015700001905035700001805054700002005072700001705092700001705109700002105126700002305147700001605170700002705186700001805213700002705231700002205258700002405280700002405304856012905328 2024 eng d00aLead-free Cs2AgBiCl6 double perovskite: experimental and theoretical insights into the self-trapping for optoelectronic applications0 aLeadfree Cs2AgBiCl6 double perovskite experimental and theoretic cJUL a476–4890 v43 a

Lead-free double perovskites (DPs) will emerge as viable and environmentally safe substitutes for Pb-halide perovskites, demonstrating stability and nontoxicity if their optoelectronic property is greatly improved. Doping has been experimentally validated as a powerful tool for enhancing optoelectronic properties and concurrently reducing the defect state density in DP materials. Fundamental understanding of the optical properties of DPs, particularly the self-trapped exciton (STEs) dynamics, plays a critical role in a range of optoelectronic applications. Our study investigates how Fe doping influences the structural and optical properties of Cs2AgBiCl6 DPs by understanding their STEs dynamics, which is currently lacking in the literature. A combined experimental–computational approach is employed to investigate the optoelectronic properties of pure and doped Cs2AgBiCl6 (Fe–Cs2AgBiCl6) perovskites. Successful incorporation of Fe3+ ions is confirmed by X-ray diffraction and Raman spectroscopy. Moreover, the Fe–Cs2AgBiCl6 DPs exhibit strong absorption from below 400 nm up to 700 nm, indicating sub-band gap state transitions originating from surface defects. Photoluminescence (PL) analysis demonstrates a significant enhancement in the PL intensity, attributed to an increased radiative recombination rate and higher STE density. The radiative kinetics and average lifetime are investigated by the time-resolved PL (TRPL) method; in addition, temperature-dependent PL measurements provide valuable insights into activation energy and exciton–phonon coupling strength. Our findings will not only deepen our understanding of charge carrier dynamics associated with STEs but also pave the way for the design of some promising perovskite materials for use in optoelectronics and photocatalysis.

1 aRahane, Swati, N.1 aRahane, Ganesh, K.1 aMandal, Animesh1 aJadhav, Yogesh1 aGodha, Akshat1 aRokade, Avinash1 aShah, Shruti1 aHase, Yogesh1 aWaghmare, Ashish1 aSaykar, Nilesh, G.1 aRoy, Anurag1 aSalgaonkar, Kranti, N.1 aDubal, Deepak1 aMakineni, Surendra, K.1 aDzade, Nelson, Y.1 aJadkar, Sandesh, R.1 aRondiya, Sachin, R. uhttp://library.ncl.res.in/content/lead-free-cs2agbicl6-double-perovskite-experimental-and-theoretical-insights-self-trapping