Z-Scheme Au@Void@g-C3N4/SnS Yolk-Shell Heterostructures for Superior Photocatalytic CO2 Reduction under Visible Light

Au@g-C3N4/SnS yolk-shell Z-scheme photocatalysts are fabricated by a simple template-assisted strategy. The L-cysteine can offer the amine groups and meanwhile anchor on the surface of g-C3N4 during solvothermal reaction and thus contributes greatly to the enhanced carbon dioxide adsorption capability. This Z-scheme photocatalytic reduction mechanism of Aupg-C3N4/SnS performs valuable functions in the reaction, leading to CH4 generation much earlier and higher concentration than that of Aupg-C3N4. Meanwhile, the unique yolk-shell structure can make the light bounce back and forth in the cavity and thus enhances the availability ratio of light. The application of small amount of noble metal cocatalysts and the large Brunauer-Emmett-Teller surface areas are also benefited for the enhanced photocatalytic activities. Hence, this novel material exhibits a distinguished reduction performance for CO2 reduction under visible light. The highest yields of CH4 (3.8 mu mol g(-1)), CH3OH (5.3 mu mol g(-1)), and CO (17.1 mu mol g(-1)) can be obtained for the sample of Aupg-C3N4/SnS (SnS 41.5%), which is higher than other latest reported g-C3N4-based photocatalysts for CO2 photoreduction including coupled with semiconductors and noble metal cocatalysts. This strategy might represent a novel way for the effective transition of CO2 to clean fuels and can also be enormous feasible utilization in the photocatalytic field.