MOF-based C-doped coupled TiO2/ZnO nanofibrous membrane with crossed network connection for enhanced photocatalytic activity

Abstract As the most widely used metal oxide catalysts in photocatalytic degradation, the fast recombination of charge carriers limits the photocatalytic performance of multiform TiO2, resulting from its direct-band-gap property. In the present work, we designed C-doped coupled TiO2/ZnO nanofibrous membrane based on the derivation of ZnO from the metal organic framework (MOF). The morphology and catalytic properties of the composite membrane could be manipulated by the growth of ZIF-8 crystals. Compared to pristine TiO2 nanofibers (11.4341 m2 g−1), the composite membrane with an optimized ZnO cubes exhibited larger specific surface area (30.2475 m2 g−1) after introducing ZnO cubes. Furthermore, the crossed-network connection between TiO2 and ZnO cubes is propitious to increase the synergy of the heterojunction, subsequently effectively inhibiting the recombination of photogenetrated holes and electrons. Benefitting from the trinomial synergistic effect of carbon doping, ZnO and TiO2, the as-designed composite membrane exhibited excellent photocatalytic performance to Rhodamine compared to pure TiO2 nanofibers. This study not only presents the strategy of preparing a C-doped coupled TiO2/ZnO composites with crossed network connection for effective photocatalysis, but also exploit the application of MOFs.