Visible-Light-Induced CO₂ Reduction by Mixed-Valence Tin Oxide

Photocatalytic carbon dioxide (CO2) reduction has been attracting considerable interest. However, the major problems with its application are that it is limited by the solar energy utilization efficiency and catalytic selectivity of CO2 reduction in water. In this study, we observed the reduction of CO2 in aqueous solution to carbon monoxide (CO) catalyzed by hydrothermally synthesized pristine tin oxide (Sn3O4) under visible-light irradiation (λ > 430 nm). The detected CO generation rate remained stable for 72 h. Because Sn3O4 is visible-light active, capable of driving CO2 reduction, environmentally benign, and stable, we believe that it is a promising photocatalyst worthy of further examination.