Selective Bonding Effect of Heterologous Oxygen Vacancies in Z-Scheme Cu2O/SrFe0.5Ta0.5O3 Heterojunctions for Constructing Efficient Interfacial Charge-Transfer Channels and Enhancing Photocatalytic NO Removal Performances.

An interfacial structure is crucial to the photoinduced electron transport for a heterostructure photocatalyst. Constructing an interfacial electron channel with an optimized interfacial structure can efficiently improve the electron-transfer efficiency. Herein, the rapid electron-transfer channels were built up in a Cu2O/SrFe0.5Ta0.5O3 heterojunction (Cu2O/SFTO) based on the selective bonding effect of heterologous surface oxygen vacancies in the SFTO component. The heterologous surface oxygen vacancies, namely, VO-Fe and VO-Ta, respectively, adjacent to Fe and Ta atoms, were introduced into fabricating the Z-scheme Cu2O/SFTO heterojunction. Compared with sample Cu2O/SFTO with VO-Fe, the photocatalytic NO removal efficiency of sample Cu2O/SFTO with VO-Fe and VO-Ta was increased by 22.5%. The enhanced photocatalytic performance originated from the selective bonding effect of heterologous VO-Fe and VO-Ta on the interfacial electron-separating and -transfer efficiency. VO-Fe is the main body to construct the interfacial electron-transfer channels by forming interfacial Fe-O-Cu(I) bonds, which causes lattice distortion at the interface, and VO-Ta can optimize the structure of interfacial channels by balancing the electron density of SFTO to control the average space of the interface transition zone. This research provides a new cognitive perspective for constructing double perovskite oxide-based heterostructure photocatalysts.