Photobreeding oxygen vacancy facilitates phtocatalytic reduction of CO2

Photocatalytic reduction of CO2 has attracted wide attention because of its clean and pollution-free nature. Poor product selectivity and catalytic activity are considered to be the main obstacles limiting the application of CO2 photoreduction. Bromine-substitued bismuth oxysulfide was prepared via hydrothermal method. The optimal bromine-substituted bismuth oxysulfide exhibits improved photocatalytic activity for CO2 reduction, with yield of CO up to 110.2 μmol⋅g−1⋅h−1, approached 100% selectivity, which is 34.4 times higher that of the original Bi2O2S. It is found that introduction of bromine for Bi2O2S is conductive to the newly photogengerated oxygen vacancy in the photocatalytic process, which is beneficial for the adsorption and activation of reactants of H2O and CO2, thus boosting the photocatalytic reduction of CO2. This work get rise to a rational design of efficient photocatalyst and understand the photocatalytic mechanism at the atomic level.