An Efficient Strategy for Tailoring Interfacial Charge Transfer Pathway on Semiconductor Photocatalysts: A Case of (BiFeO3)x(SrTiO3)1−x/Mn3O4

Abstract The ability to generate heterostructures with a desirable charge transfer pathway is essential for achieving semiconductor photocatalysts with super photocatalytic activity. Herein, it is proposed to realize robust tailoring of effective charge transfer pathway in semiconductor‐based heterostructures via work function regulation, and elucidate the influence of the work function of the semiconductor on the charge transfer mechanism at the heterostructure interface. Specifically, taking type‐II heterostructure SrTiO 3 /Mn 3 O 4 as an example, introducing BiFeO 3 into SrTiO 3 effectively regulate the work function of the (BiFeO 3 ) x (SrTiO 3 ) 1− x /Mn 3 O 4 (B x T 1− x /Mn 3 O 4 ) solid solution through optimizing the x value. Combined with in situ testing, the results show that the original type‐II heterojunction SrTiO 3 /Mn 3 O 4 is converted into S‐scheme heterojunction (BiFeO 3 ) 0.3 (SrTiO 3 ) 0.7 /Mn 3 O 4 when BiFeO 3 is introduced. This increases the work function of the semiconductor, inducing the light‐generated carriers to be guided and separated by the generated built‐in electric field. Therefore, the implementation of this strategy can achieve efficient photocatalytic CO 2 reduction. In contrast to pristine SrTiO 3 /Mn 3 O 4 , the (BiFeO 3 ) 0.3 (SrTiO 3 ) 0.7 /Mn 3 O 4 heterostructure exhibits a 28‐fold enhancement of in electron consumption rate during photocatalytic CO 2 reduction, and the reaction mechanism is suggested. In this study, a strategy for effectively converting interfacial charge transfer pathways in semiconductor photocatalysts is developed to enhance the photoconversion kinetics of CO 2 and H 2 O.