02917nas a2200229 4500008004100000022001400041245015400055210006900209260000900278300001600287490000700303520206700310100002702377700002102404700002302425700002102448700002302469700002002492700001802512700003002530856012702560 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. uhttps://library.ncl.res.in/content/baby-step-assembling-and-integrating-components-artificial-photosynthesis-device-forced01973nas a2200241 4500008004100000022001400041245007800055210006900133260000800202300001200210490000800222520119700230653001801427653003701445653001901482653002601501100001701527700002001544700002001564700001801584700001901602856011001621 2023 eng d a0021-979700aPhotoinduced CO2 and N2 reductions on plasmonically enabled gallium oxide0 aPhotoinduced CO2 and N2 reductions on plasmonically enabled gall cJAN a654-6660 v6293 a

Ag-containing ZnO/ b-Ga2O3 semiconductor, which exhibit reduced bandgap, increased light absorption, and hydrophilicity, have been found to be useful for photocatalytic CO2 reduction and N2 fixation by water. The charge-separation is facilitated by the new interfaces and inherent vacancies. The Ag@GaZn demonstrated the highest photocurrent response, about 20-and 2.27-folds that of the Ga and GaZn sam-ples, respectively. CO, CH4, and H2 formed as products for photo-reduction of CO2. Ag@GaZn catalyst exhibited the highest AQY of 0.121 % at 400 nm (31.2 W/m2). Also, Ag@GaZn generated 740 lmolg-1 of NH4+ ions, which was about 18-folds higher than Ga sample. In situ DRIFTS for isotopic-labelled 13CO2 and 15N2 reaffirmed the photo-activity of as-synthesized catalysts. Density functional theory pro-vided insight into the relative affinity of different planes of heterostructures towards H2O, CO2 and N2 molecules. The structure-photoactivity rationale behind the intriguing Ag@GaZn sample offers a funda-mental insight into the role of plasmonic Ag and design principle of heterostructure with improved pho-toactivity and stability.(c) 2022 Elsevier Inc. All rights reserved.

10aCO2 reduction10aDRIFTS density functional theory10ahydrophilicity10aPhotocurrent response1 aOjha, Niwesh1 aThakkar, Kavita1 aBajpai, Abhinav1 aJoshi, Kavita1 aKumar, Sushant uhttps://library.ncl.res.in/content/photoinduced-co2-and-n2-reductions-plasmonically-enabled-gallium-oxide01865nas a2200193 4500008004100000022001400041245010100055210006900156260000900225490000800234520121600242653002201458653000801480653001001488653001001498100002001508700001801528856012501546 2024 eng d a2468-823100aExploring the catalytic potential of Mg-Cu alloys for enhanced activity toward CO2 hydrogenation0 aExploring the catalytic potential of MgCu alloys for enhanced ac cMAR 0 v5563 a

CO2, a well-known greenhouse gas, is a potential raw material that can produce various chemicals. Dissociation of CO2 to CO or hydrogenation to formate (HCOO*) or carboxyl (COOH*) intermediate is crucial in determining the reaction pathway for CO2 conversion. In this work, we demonstrate that alloys of Mg-Cu exhibit greater activity toward activation and hydrogenation of CO2 than transition metal alloys reported so far. Two different compositions of Mg-Cu, namely Mg2Cu and MgCu2, have been studied using periodic Density Functional Theory (DFT). Our investigations reveal that CO2 chemisorbs on both intermetallic alloys. Coadsorption of CO2 with H2O leads to the spontaneous formation of COOH* over Mg2Cu(224), whereas a negligible barrier (0.04 eV) is observed for MgCu2(311). HCOO* formation has a barrier of 0.34 eV and 0.42 eV on Mg2Cu(224) and MgCu2(311), respectively. Dissociation of CO2 to CO is kinetically unfavourable on both compositions of Mg-Cu. We provide a rationale for the observed activity by analyzing the electronic structure. Notably, the spontaneous hydrogenation of CO2 makes earth -abundant metals suitable candidates for alloying that await experimental verification.

10aCO2 hydrogenation10aDFT10aMg2Cu10aMgCu21 aThakkar, Kavita1 aJoshi, Kavita uhttps://library.ncl.res.in/content/exploring-catalytic-potential-mg-cu-alloys-enhanced-activity-toward-co2-hydrogenation01655nas a2200193 4500008004100000022001400041245010800055210006900163260000800232490000800240520099200248653000801240653001201248653000801260653002601268100002001294700001801314856012901332 2024 eng d a1093-326300aSingle-atom alloys of Cu(211) with earth-abundant metals for enhanced activity towards CO2 dissociation0 aSingleatom alloys of Cu211 with earthabundant metals for enhance cJAN0 v1263 a

CO2, a byproduct from various industrial reactions, must not be released into the atmosphere and should be managed through capture, conversion, and utilization. The first step in converting CO2 into valuable products is to break the C-O bond. This work focuses on designing Single Atom Catalysts (SACs) by doping Cu(211) surface with 13 different s, p, and d block elements with an aim to minimize the activation barrier for C-O bond cleavage. Our work demonstrates that SACs of Mg/Al/Pt@Cu(211) favor CO2 chemisorption compared to Cu(211) where CO2 physisorbs. The barrier for CO2 dissociation is lowest for Mg@Cu(211) and it increases in the order Mg@Cu(211) < Al@Cu(211) < Pt@Cu(211) < Zn@Cu(211) < Ga@Cu(211) < Cu@Cu(211) < Pd@Cu(211). These findings suggest that doping Cu(211) with earth-abundant metal like Mg can potentially be a viable catalyst for CO2 conversion, providing a promising solution to reduce carbon footprint and mitigate climate change.

10aCO210aCu(211)10aDFT10aSingle atom catalysts1 aThakkar, Kavita1 aJoshi, Kavita uhttps://library.ncl.res.in/content/single-atom-alloys-cu211-earth-abundant-metals-enhanced-activity-towards-co2-dissociation