Metal to non-metal sites of metallic sulfides switching products from CO to CH4 for photocatalytic CO2 reduction

Abstract

The active center for the adsorption and activation of carbon dioxide plays a vital role in the conversion and product selectivity of photocatalytic CO2 reduction. Here, we find multiple metal sulfides CuInSnS4 octahedral nanocrystal with exposed (1 1 1) plane for the selectively photocatalytic CO2 reduction to methane. Still, the product is switched to carbon monoxide on the corresponding individual metal sulfides In2S3, SnS2, and Cu2S. Unlike the common metal or defects as active sites, the non-metal sulfur atom in CuInSnS4 is revealed to be the adsorption center for responding to the selectivity of CH4 products. The carbon atom of CO2 adsorbed on the electron-poor sulfur atom of CuInSnS4 is favorable for stabilizing the intermediates and thus promotes the conversion of CO2 to CH4. Both the activity and selectivity of CH4 products over the pristine CuInSnS4 nanocrystal can be further improved by the modification of with various co-catalysts to enhance the separation of the photogenerated charge carrier. This work provides a non-metal active site to determine the conversion and selectivity of photocatalytic CO2 reduction.

Hydroxyl-Bonded Ru on Metallic TiN Surface Catalyzing CO2 Reduction with H2O by Infrared Light

“…The HO-Ru/TiN electrode affords a higher photocurrent generation than TiN (Figure S28a), mirroring the quicker charge transport of HO-Ru/TiN, which matches with its lower electronic resistance revealed by EIS (Figure S28b). Further, HO-Ru/TiN manifests a markedly reduced PL intensity than TiN (Figure S28c), reflecting the suppressed recombination of charge carriers on TiN after decorating Ru species . These outcomes confirm that HO-Ru/TiN maintains accelerated separation and transfer of the charge carriers to allow for CO 2 photoreduction.…”

Photocatalytic Conversion of CO2 to CO with a p–n Heterojunction Based on Core–Shell β-Ga2O3@CoGa2O4 Nanorods

“…Also, the potential versus the Ag/AgCl electrode was converted to the NHE scale using E (NHE) = E (Ag/AgCl) + 0.197 V (pH = 7) . Using the formula E g = E VB – E CB , , where E g represents the band gap, E VB signifies the valence band potential, and E CB denotes the conduction band potential, we can estimate that the CB potential for β-Ga 2 O 3 and the VB potential for CoGa 2 O 4 are estimated to be about −1.40 and 2.16 V (vs NHE), respectively. Thus, a possible band structure based on the p–n heterojunction can be formed in the CG/GO composite consisting of an n-type β-Ga 2 O 3 core and a p-type CoGa 2 O 4 shell.…”

Tailoring Charge Separation in ZnIn2S4@CdS Hollow Nanocages for Simultaneous Alcohol Oxidation and CO2 Reduction under Visible Light

“…2 It attracts broad research interest and has been demonstrated as a potential strategy to address energy crisis and environment problems. 2−13 Up to date, various kinds of catalysts such as metal−organic frameworks (MOFs), 3−5 metallic oxides, 6,7 metallic sulfides, 8,9 covalent organic frameworks (COFs), 10,11 and compounds 12,13 are developed to drive multielectron CO 2 reduction. However, the sluggish oxidation reaction (2H 2 O + 4h + → 4H + + O 2 ) triggered by photoexcited holes (h + ) greatly limited the photocatalytic activity of these photocatalysts.…”

“…Artificial photosynthesis via coupling photocatalytic reduction of CO 2 with oxidation of H 2 O is a promising technology that can be used to convert solar energy into usable fuels and fine chemicals in a sustainable way . It attracts broad research interest and has been demonstrated as a potential strategy to address energy crisis and environment problems. − Up to date, various kinds of catalysts such as metal–organic frameworks (MOFs), − metallic oxides, , metallic sulfides, , covalent organic frameworks (COFs), , and compounds , are developed to drive multielectron CO 2 reduction. However, the sluggish oxidation reaction (2H 2 O + 4h + → 4H + + O 2 ) triggered by photoexcited holes (h + ) greatly limited the photocatalytic activity of these photocatalysts. − Although sacrificial reagents can help to improve CO 2 reduction activity, the expenses should not be overlooked such as cost-push, whole energy dissipation, secondary pollution, etc .…”