Photocatalytic Reduction of CO2 to CO over 3D Bi2MoO6 Microspheres: Simple Synthesis, High Efficiency and Selectivity, Reaction Mechanism

It has been a promising approach for directly utilizing solar energy to convert CO 2 into clean renewable chemical fuels over photocatalysts with excellent photoreactivity, CO 2 adsorption capacity and reasonable redox potentials. In this work, as-synthesized 3D Bi 2 MoO 6 microspheres with cross-stacking nanosheets via a simple hydrothermal method have been investigated for photocatalytic CO 2 reduction, and characterized by XRD, UV–Vis DRS, SEM, HRTEM and BET. It was found that as-prepared samples exhibited high Bi 2 MoO 6 purity, large specific surface area, excellent light response and CO 2 adsorption capacity, achieving superior photocatalytic CO 2 reduction activity and selectivity of CO yield (41.5 μmol g −1 h −1 ). Moreover, the photocatalytic reaction mechanism for CO 2 reduction to CO over 3D Bi 2 MoO 6 microspheres was investigated and proposed. Finally, COOH* was verified to be a key intermediate for photocatalytic CO 2 reduction to CO by the analysis of in-situ FTIR. Our findings should provide excellent foundation and guidance for boosting photocatalytic CO 2 conversion to CO with enhanced effective and selective ability. Graphic Abstract 3D Bi 2 MoO 6 microspheres with cross-stacking nanosheets exhibit large specific surface area, excellent light response and CO 2 adsorption capacity. COOH*, as a key reaction intermediate, can significantly reduce the activation energy of CO 2 .