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.