Bimetal-organic frameworks derived carbon doped ZnO/Co3O4 heterojunction as visible-light stabilized photocatalysts

The construction of transition-metal oxygen heterojunction photocatalysts has been paid close attention for application of versatile functionalities. Many methods have been developed and applied to improve photocatalytic performance, such as doping and morphology control. In this study, carbon (C)-doped binary oxide heteronanostructures with hollow dodecahedra morphology are fabricated by means of topotactic transformation of metal-organic frameworks. The converted hollow C doping ZnO/Co3O4 nanocomposite with large specific area has advantage in charge transfer and charge-separation efficiency, and then is evaluated by degrading methylene blue (MB) under visible light irradiation (λ > 400 nm). The experiment demonstrates the optimal catalytic performance is about 8.4-fold k values of pure ZnO. Importantly, the in-situ synthesized composites show noteworthy stability and recyclability, even after five runs. A possible photocatalytic mechanism also is mentioned, the results illustrate that synergistic effect of coupled semiconductor system with C doping dramatically suppresses the recombination of photogenerated electron-hole pairs, and the hydroxyl radicals (
- OH) and holes play a critical role. This work exhibits an effective method for the design of other nonmetal doping sound heterojunctions with well-controlled morphology that significantly enhance photocatalytic behavior.