Efficient Spatial Charge Separation and Transfer in SrTiO₃ Nanospheres Modified with Ag₂O as a Co-Catalyst for Superior Visible Light-Driven Photocatalytic Degradation of Toluene

Construction of coupled composite heterojunctions is an effective strategy for achieving high photocatalytic performance of SrTiO₃(STO) perovskite. Herein, we synthesized Ag₂O-STO heterostructure piezocatalysts using a simple one-step wet chemical method and evaluated its performance for full-spectrum photocatalytic degradation of toluene. Our findings reveal that the Ag₂O-STO heterostructure demonstrates excellent catalytic activity, with a toluene conversion rate of 70%, which is 2.7 times that of STO. Furthermore, it showed good stability in five photocatalytic cycling experiments. The excellent catalytic performance of Ag₂O-STO was attributed to the formation of p–n heterostructures, which induced the generation of a strong electrostatic field effect, providing a driving force for the transport of carriers and lowering the recombination or complexation rate, which could be confirmed by the photocurrent response. A possible mechanism of Ag₂O-STO heterostructure is proposed. It is expected that this study can provide new understanding for the rational design of highly efficient photocatalysts for potential practical applications.