Metal–organic framework (MOF)-5/CuO@ZnIn2S4 core–shell Z-scheme tandem heterojunctions for improved charge separation and enhanced photocatalytic performance

Abstract

Interface engineering is regarded as an effective strategy for charge separation. Metal–organic framework (MOF)-5/CuO@ZnIn₂S₄ core–shell Z-scheme tandem heterojunctions with a three-dimensional floral spherical shape are prepared by a two-step solvothermal and oxidative method. The flower spherical core–shell structure enhances multiple reflections and refractions of light and thus improves light utilization efficiently. In addition, this core–shell structure can supply sufficient active sites for photocatalytic reactions. Meanwhile, the composition of Z-scheme tandem heterojunctions and the photothermal effect contributed to the spatial charge separation and accelerated the photocatalytic process. The photocatalytic hydrogen production rate of MOF-5/CuO@ZnIn₂S₄ (1938.3 μmol g⁻¹ h⁻¹) is 18 times higher than that of pristine MOF-5, and the photocatalytic degradation efficiency of 2,4-dichlorophenol and phenol can reach up to 98.7% and 97.3%, respectively. In addition, multiple cycle experiments demonstrate high stability, which is favorable for practical applications.