Modulating Surface-Adsorbed Oxygen Species of Bismuth Silicate by a Solid Solution Strategy for Efficient Adsorption and Photocatalytic Activity

Bismuth silicate photocatalysts suffer from insufficient photocatalytic activity due to an insufficient number of surface active sites and low carrier separation and transport efficiency, which can be solved by defect modulation. Herein, Bi₁₂SiO₂₀/Bi₂O₂SiO₃-BiOCl_<i>x</i>Br_1-<i>x</i> (BSOCB) photocatalysts with a high concentration of surface-adsorbed oxygen species (SAOS) are synthesized by introducing a BiOCl_<i>x</i>Br_1-<i>x</i> solid solution to modify nonhomogeneous BSO via an ion exchange strategy. The introduction of a solid solution enables the generation of dispersed nanoflowers and the regulation of SAOS due to the fact that anion-cation copolymerization guides the crystal growth, and the defects generated by the lattice distortion modulate the concentration of SAOS on the catalysts during the solid solution process. The obtained typical BSOCB photocatalyst possesses both high adsorption and photocatalytic properties, and the results show that it not only can almost completely degrade the traditional pollutant RhB within 20 min but also strongly degrades antibiotics, such as CIP (light for 150 min, 96%), NFX (light for 150 min, 87%), and TC (light for 150 min, 77%). This work provides a new approach for obtaining bismuth-based photocatalysts with controllable morphology and a large number of surface active sites and provides a theoretical and experimental basis for expanding the application scenarios of photocatalysts.