CO2 reduction synergistic tetracycline degradation toward Co-BiOBr ultrathin nanosheets with rich defects and (102) active faces

The development of bifunctional reaction by combining CO2 reduction with antibiotics degradation is of great significance. Designing bifunctional catalysts with excellent performance is the focus of scholars' research. In this paper, Co-doped BiOBr ultra-thin nanosheets exposing rich (102) active crystal faces were prepared by one-step hydrothermal method. Since Co2+ has a smaller radius than Bi3+, Co was successfully incorporated into the lattice of BiOBr, which changed the crystal structure of BiOBr and obtained thinner nanosheets with rich lattice defects. The Gibbs free energy of CO2 reduction reaction was synergistically optimized by the combination of exposing (102) active crystal faces and introducing lattice defects. In addition, the addition of Co changed the band structure of BiOBr and improved the carrier separation ability, making Co-BiOBr be an excellent bi-functional photocatalyst for CO2 reduction and co-degradation of tetracycline, realizing the synergistic process of environmental purification and energy conversion. This work provides theoretical and experimental reference for the rational design of bifunctional photocatalysts.