02500nas a2200301   4500008004100000022001400041245012000055210006900175260000900244300001200253490000700265520151200272653001801784653002001802653001201822653001901834653001301853100001501866700001901881700001801900700002801918700002201946700002001968700002801988700002702016700002502043856013002068       2022                        eng d  a2155-543500aNoble-metal-free heterojunction photocatalyst for selective CO2 reduction to methane upon induced strain relaxation0 aNoblemetalfree heterojunction photocatalyst for selective CO2 re  cJAN   a687-6970 v123 a<p>
	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.</p>
10aCO2 reduction10aheterostructure10amethane10aPhotocatalysis10aZ-scheme1 aDas, Risov1 aSarkar, Shreya1 aKumar, Ritesh1 aRamarao, Seethiraju, D.1 aCherevotan, Arjun1 aJasil, Mohammed1 aVinod, Chathakudath, P.1 aSingh, Abhishek, Kumar1 aPeter, Sebastian, C.  uhttps://library.ncl.res.in/content/noble-metal-free-heterojunction-photocatalyst-selective-co2-reduction-methane-upon-induced02564nas a2200289   4500008004100000022001400041245013800055210006900193260000800262490000700270520158500277653001701862653002401879653001801903653001201921653001901933100001601952700001501968700001601983700001601999700002202015700002702037700002702064700002802091700002502119856013002144       2023                        eng d  a0935-964800aIntrinsic charge polarization in Bi19S27Cl3 nanorods promotes selective C-C coupling reaction during photoreduction of CO2 to ethanol0 aIntrinsic charge polarization in Bi19S27Cl3 nanorods promotes se  cFEB0 v353 a<p>
	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.</p>
10aC-C coupling10acharge polarization10aCO2 reduction10aEthanol10aPhotocatalysis1 aDas, Kousik1 aDas, Risov1 aRiyaz, Mohd1 aParui, Arko1 aBagchi, Debabrata1 aSingh, Ashutosh, Kumar1 aSingh, Abhishek, Kumar1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C.  uhttps://library.ncl.res.in/content/intrinsic-charge-polarization-bi19s27cl3-nanorods-promotes-selective-c-c-coupling-reaction