@article {46197, title = {Direct Z-scheme g-C3N4/FeWO4 nanocomposite for enhanced and selective photocatalytic CO2 reduction under visible light}, journal = {ACS Applied Materials \& Interfaces}, volume = {11}, year = {2019}, month = {FEB }, pages = {6174-6183}, type = {Article}, abstract = {

Photocatalytic reduction of CO2 to renewable solar fuels is considered to be a promising strategy to simultaneously solve both global warming and energy crises. However, development of a superior photocatalytic system with high product selectivity for CO2 reduction under solar light is the prime requisite. Herein, a series of nature-inspired Z-scheme g C3N4/FeWO4 composites are prepared for higher performance and selective CO2 reduction to CO as solar fuel under solar light. The novel direct Z-scheme coupling of the visible light-active FeWO4 nanoparticles with C3N4 nanosheets is seen to exhibit excellent performance for CO production with a rate of 6 mu mol/g/h at an ambient temperature, almost 6 times higher compared to pristine C3N4 and 15 times higher than pristine FeWO4. More importantly, selectivity for CO is 100\% over other carbon products from CO, reduction and more than 90\% over. H-2 products from water splitting. Our results clearly demonstrate that the staggered band structure between FeWO4 and C3N4 reflecting the nature-inspired Z-scheme system not only favors superior spatial separation of the electron hole pair in g-C3N4/FeWO4 but also shows good reusability. The present work provides unprecedented insights for constructing the direct Z-scheme by mimicking the nature for high performance and selective photocatalytic CO2 reduction into solar fuels under solar light.

}, keywords = {C3N4, CO2 reduction, FeWO4, Photocatalysis, solar fuels, Z-scheme}, issn = {1944-8244}, doi = {10.1021/acsami.8b22434}, author = {Bhosale, Reshma and Jain, Srashti and Vinod, Chathakudath Prabhakaran and Kumar, Santosh and Ogale, Satishchandra} } @article {48391, title = {First-principles investigation of the electrocatalytic reduction of CO2 on zirconium-based single-, double-, and triple-atom catalysts anchored on a graphitic carbon nitride monolayer}, journal = {ACS Applied Nano Materials}, volume = {5}, year = {2022}, month = {OCT}, pages = {15409-15417}, type = {Article}, abstract = {

Conversion of carbon dioxide (CO2) with the help of an appropriate electrocatalyst with high stability, low onset potential, and exceptional selectivity is still one of the great tasks in the electrocatalytic reduction of CO2 to valuable chemicals. Herein, by means of systematic first-principles simulations, we investigate the CO2 reduction reaction (CO2RR) activity of zirconium-based single-, double-, and triple-atom (Zrn@C2N; n = 1-3) catalysts anchored on a graphitic carbon-nitride monolayer. In tune with the Sabatier principle, our results reveal that a moderate CO2 binding is vital for a low onset potential for the CO2RR. Consequently, based on rigorous free energy calculations, the Zr-based single-atom catalyst (SAC) is found to be most effective to convert CO2 to valuable products such as HCOOH and CH3OH. It is worth noting that CO2 reduction to HCOOH is spontaneous via the *HCOO intermediate on Zr1@C2N and involves a low onset potential of -0.23 V with respect to the reversible hydrogen electrode from the *COOH intermediate. Among all the catalysts evaluated computationally, the Zr SAC further reveals the lowest onset potential of -0.89 V for CH3OH formation. The results show that the Zr-based catalysts especially Zr1@C2N are found to effectively suppress the competitive hydrogen evolution reaction and promote the CO2RR. Moreover, all three catalysts exhibit high kinetic and thermal stability with negligible distortion due to which their structures can be retained very well up to 600 K. Thus, the current work may provide effective catalyst-design strategies for enhancing the electrocatalytic CO2RR performance of Zr-based materials.

}, keywords = {C1 and C2 products, CO2 reduction, first-principles simulations, hydrogen evolution reaction, onset potential, single-atom catalysts (SACs), Zrn@C2N catalysts}, doi = {10.1021/acsanm.2c03464}, author = {Hassan, Afshana and Anis, Insha and Shafi, Sadaf and Assad, Assif and Rasool, Anjumun and Khanam, Romana and Bhat, Gulzar Ahmad and Krishnamurty, Sailaja and Dar, Manzoor Ahmad} } @article {48415, title = {Noble-metal-free heterojunction photocatalyst for selective CO2 reduction to methane upon induced strain relaxation}, journal = {ACS Catalysis}, volume = {12}, year = {2022}, month = {JAN }, pages = {687-697}, type = {Article}, abstract = {

Sunlight-driven CO2 hydrogenation has drawn tremendous attention. However, selective CH4 formation via CO2 photoreduction is very challenging. Herein, we report a metal oxide semiconductor heterojunction consisting of BiVO4 and WO3 as a photocatalyst for the efficient conversion of carbon dioxide (CO2) selectively to methane (105 mu mol g(-1) h(-1)) under visible light in the absence of a sacrificial agent. Wise selection of the reaction medium and the strategically tuned heterojunction upon strain relaxation suppresses the competitive hydrogen generation reaction. The detailed photophysical, photoelectrochemical, and X-ray absorption spectroscopy studies pointed to the Z-scheme mechanism of electron transfer, which favors superior electron and hole separation compared to the individual components of the composite catalyst and other well-known photocatalysts reported for CO2 reduction. The observations are further corroborated by experimental diffuse reflectance infrared Fourier transform spectroscopy and theoretical density-functional theory calculations, which reveal that the heterojunction has a lower free-energy barrier for CO2 conversion to CH4 due to the larger stabilization of the *CH2O intermediate on the strain-relaxed heterojunction surface, in comparison to the pristine BiVO4 surface. The present work provides fundamental insights for constructing high-performance heterojunction photocatalysts for the selective conversion of CO2 to desired chemicals and fuels.

}, keywords = {CO2 reduction, heterostructure, methane, Photocatalysis, Z-scheme}, issn = {2155-5435}, doi = {10.1021/acscatal.1c04587}, author = {Das, Risov and Sarkar, Shreya and Kumar, Ritesh and Ramarao, Seethiraju D. and Cherevotan, Arjun and Jasil, Mohammed and Vinod, Chathakudath P. and Singh, Abhishek Kumar and Peter, Sebastian C.} } @article {48094, title = {Potential- and time-dependent dynamic nature of an oxide-derived pdin nanocatalyst during electrochemical CO2 reduction}, journal = {ACS Nano}, volume = {16}, year = {2022}, month = {APR}, pages = {6185-6196}, type = {Article}, abstract = {

Electrochemical reduction of CO2 into valuable fuels and chemicals is a promising route of replacing fossil fuels by reducing CO2 emissions and minimizing its adverse effects on the climate. Tremendous efforts have been carried out for designing efficient catalyst materials to selectively produce the desired product in high yield from CO2 by the electrochemical process. In this work, a strategy is reported to enhance the electrochemical CO2 reduction reaction (ECO2RR) by constructing an interface between a metal-based alloy (PdIn) nanoparticle and an oxide (In2O3), which was synthesized by a facile solution method. The oxide-derived PdIn surface has shown excellent eCO(2)RR activity and enhanced CO selectivity with a Faradaic efficiency (FE) of 92.13\% at -0.9 V (vs RHE). On the other hand, surface PdO formation due to charge transfer on the bare PdIn alloy reduces the CO2RR activity. With the support of in situ (EXAFS and IR) and ex situ (XPS, Raman) spectroscopic techniques, the optimum presence of the Pd-In-O interface has been identified as a crucial parameter for enhancing eCO(2)RR toward CO in a reducing atmosphere. The influence of eCO(2)RR duration is reported to affect the overall performance by switching the product selectivity from H-2 (from water reduction) to CO (from eCO(2)RR) on the oxide-derived alloy surface. This work also succeeded in the multifold enhancement of the current density by employing the gas diffusion electrode (GDE) and optimizing its process parameters in a flow cell configuration.

}, keywords = {CO2 reduction, Electrochemistry, heterostructure interface, in situ mechanism, nanocatalyst}, issn = {1936-0851}, doi = {10.1021/acsnano.1c11664}, author = {Bagchi, Debabrata and Sarkar, Shreya and Singh, Ashutosh Kumar and Vinod, Chathakudath P. and Peter, Sebastian C.} } @article {48450, title = {Intrinsic charge polarization in Bi19S27Cl3 nanorods promotes selective C-C coupling reaction during photoreduction of CO2 to ethanol}, journal = {Advanced Materials}, volume = {35}, year = {2023}, month = {FEB}, type = {Article}, abstract = {

Obtaining multi-carbon products via CO2 photoreduction is a major catalytic challenge involving multielectron-mediated C-C bond formation. Complex design of multicomponent interfaces that are exploited to achieve this chemical transformation, often leads to untraceable deleterious changes in the interfacial chemical environment affecting CO2 conversion efficiency and product selectivity. Alternatively, robust metal centers having asymmetric charge distribution can effectuate C-C coupling reaction through the stabilization of intermediates, for desired product selectivity. However, generating inherent charge distribution in a single component catalyst is a difficult material design challenge. Here, a novel photocatalyst, Bi19S27Cl3, is presented which selectively converts CO2 to a C-2 product, ethanol, in high yield under visible light irradiation. Structural analysis through transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy reveals the presence of charge polarized bismuth centers in Bi19S27Cl3. The intrinsic electric field induced by charge polarized bismuth centers renders better separation efficiency of photogenerated electron-hole pair. Furthermore, charge polarized centers yield better adsorption of CO* intermediate and accelerate the rate determining C-C coupling step through the formation of OCCOH intermediate. Formation of these intermediates is experimentally mapped by in situ Fourier-transform infrared spectroscopy and further confirmed by theoretical calculation.

}, keywords = {C-C coupling, charge polarization, CO2 reduction, Ethanol, Photocatalysis}, issn = {0935-9648}, doi = {10.1002/adma.202205994}, author = {Das, Kousik and Das, Risov and Riyaz, Mohd and Parui, Arko and Bagchi, Debabrata and Singh, Ashutosh Kumar and Singh, Abhishek Kumar and Vinod, Chathakudath P. and Peter, Sebastian C.} } @article {48320, title = {Photoinduced CO2 and N2 reductions on plasmonically enabled gallium oxide}, journal = {Journal of Colloid and Interface Science}, volume = {629}, year = {2023}, month = {JAN}, pages = {654-666}, type = {Article}, abstract = {

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.

}, keywords = {CO2 reduction, DRIFTS density functional theory, hydrophilicity, Photocurrent response}, issn = {0021-9797}, doi = {10.1016/j.jcis.2022.09.097}, author = {Ojha, Niwesh and Thakkar, Kavita and Bajpai, Abhinav and Joshi, Kavita and Kumar, Sushant} } @article {48962, title = {Wurtzite CuGaS2 with an in-situ-formed CuO layer photocatalyzes CO2 conversion to ethylene with high selectivity}, journal = {Angewandte chemie-international edition}, volume = {62}, year = {2023}, month = {FEB 20}, type = {Article}, abstract = {

We present surface reconstruction-induced C-C coupling whereby CO2 is converted into ethylene. The wurtzite phase of CuGaS2. undergoes in situ surface reconstruction, leading to the formation of a thin CuO layer over the pristine catalyst, which facilitates selective conversion of CO2 to ethylene (C2H4). Upon illumination, the catalyst efficiently converts CO2 to C2H4 with 75.1 \% selectivity (92.7 \% selectivity in terms of R-electron) and a 20.6 mu mol g(-1) h(-1) evolution rate. Subsequent spectroscopic and microscopic studies supported by theoretical analysis revealed operando-generated Cu2+, with the assistance of existing Cu+, functioning as an anchor for the generated *CO and thereby facilitating C-C coupling. This study demonstrates strain-induced in situ surface reconstruction leading to heterojunction formation, which finetunes the oxidation state of Cu and modulates the CO2 reduction reaction pathway to selective formation of ethylene.

}, keywords = {C-C coupling, charge polarization, CO2 reduction, Photocatalysis}, issn = {1433-7851}, doi = {10.1002/anie.202216613}, author = {Chakraborty, Subhajit and Das, Risov and Riyaz, Mohd and Das, Kousik and Singh, Ashutosh Kumar and Bagchi, Debabrata and Vinod, Chathakudath P. and Peter, Sebastian C.} } @article {49261, title = {Ligand isomerization driven electrocatalytic switching}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {63}, year = {2024}, month = {JUL}, type = {Journal Article}, keywords = {Catalysts, CO2 reduction, O-2 REDUCTION, oxygen reduction}, issn = {1433-7851}, doi = {10.1002/anie.202405664}, author = {Kottaichamy, Alagar Raja and Nazrulla, Mohammed Azeezulla and Parmar, Muskan and Thimmappa, Ravikumar and Devendrachari, Mruthyunjayachari Chattanahalli and Vinod, Chathakudath Prabhakaran and Volokh, Michael and Kotresh, Harish Makri Nimbegondi and Shalom, Menny and Thotiyl, Musthafa Ottakam} } @article {49066, title = {Photocatalytic CO2 reduction to syngas using nickel phosphide-loaded CdS under visible light irradiation}, journal = {Journal of Physics-Energy}, volume = {6}, year = {2024}, month = {APR }, pages = {025019}, type = {Article}, abstract = {

Photocatalytic CO2 reduction is a sustainable pathway to produce syngas (H-2 + CO), which is a key feedstock for the production of several important liquid fuels on the industrial scale. However, achieving an appropriate tunable ratio of H-2:CO in syngas for commercial purposes is a challenging task. In this work, we present a low-cost and non-noble metal, phosphide-based co-catalyst-Ni2P-loaded cadmium sulfide (CdS) photocatalyst system, for photocatalytic CO2 reduction. As a co-catalyst, Ni2P fosters an efficient charge separation of photoexcited charges generated in the CdS production of syngas. In total, 3 wt.\% Ni2P/CdS exhibited exceptional performance of 50.6 mu mol g(-1) h(-1) in the CO evolution rate and 115 mu mol g(-1) h(-1) in the H-2 evolution rate, with a syngas composition varying from 2 to 4 in the H-2:CO ratio. Furthermore, first-principles density functional theory calculations were performed to study the surface energetics of the catalyst system and the results are found to be consistent with our experimental findings. Indeed, they establish that the composite favors CO2 photoreduction into syngas more efficiently than pure surfaces.

}, keywords = {CdS, CO2 reduction, Photocatalysis, Syngas, transition metal phosphides}, issn = {2515-7655}, doi = {10.1088/2515-7655/ad3676}, author = {Yadav, Poonam and Kumar, Santosh and Velankanni, Nandhakumar and Kuehne, Thomas D. and Gosavi, Suresh and Raghupathy, Ramya Kormath Madam and Bhosale, Reshma and Held, Georg and Shelke, Manjusha and Ogale, Satishchandra} } @article {49246, title = {Switchable molecular electrocatalysis}, journal = {CHEMICAL SCIENCE}, volume = {15}, year = {2024}, month = {AUG }, pages = {13262-13270}, type = {Journal Article}, keywords = {CO2 reduction, COBALT PHTHALOCYANINE, NANOPOROUS GOLD, oxygen reduction}, issn = {2041-6520}, doi = {10.1039/d4sc01284d}, author = {Dutt, Shifali and Kottaichamy, Alagar Raja and Dargily, Neethu Christudas and Mukhopadhyay, Sanchayita and Nayak, Bhojkumar and Devendrachari, Mruthyunjayachari Chattanhali and Vinod, Chatakudhath Prabakaran and Kotresh, Harish Makri Nimbegondi and Thotiyl, Musthafa Ottakam} }