One-step hydrothermal synthesis of S-scheme heterojunction Bi2O3/Bi2Sn2O7 composites with enhanced photocatalytic CO2 reduction performance

In this study, a kind of S-scheme heterojunction Bi2O3/Bi2Sn2O7 composite material is firstly prepared by one-step hydrothermal method through adjusting the molar amount of Bi source, which further improves the photocatalytic CO2 reduction performance compared with pure Bi2Sn2O7. Combined with work-enthalpy data using density functional theory calculations, the photoexcited electrons are directionally transferred from Bi2O3 to Bi2Sn2O7 for the formation of S-scheme mechanism, achieving the significant improvement in the photoinduced charge separation efficiency and CO2 photoreduction activity to CO for as-prepared Bi2O3/Bi2Sn2O7 composite. A feasible photocatalytic CO2 reduction mechanism of S-scheme heterojunction Bi2O3/Bi2Sn2O7 composite is proposed and investigated. Our findings should provide the significant theoretical guidance and experimental data for achieving the S-scheme heterojunction construction and CO2 green conversion into low-carbon chemical fuels.