Preparation of core-shell MOF-5/Bi2WO6 composite for the enhanced photocatalytic degradation of pollutants

Abstract

In this study, Bi2WO6 was used as carrier and the core-shell MOF-5/Bi2WO6 (MOF-5/BWO) photocatalyst was prepared successfully by a two-step hydrothermal method for the first time. The easily hydrolyzed MOF-5 was compounded with flower-like Bi2WO6, and the hydrolyzed sheet-like MOF-5 was evenly wrapped on the surface of flower-like Bi2WO6. A type-Ⅰheterojunction photocatalytic reaction mechanism was proposed, ·O2− and h+ were the main active substances in the photocatalysis process. Compare with Bi2WO6, 9% MOF-5/BWO has the best degradation activity, and the photocatalytic degradation of RhB can reach 99.31% in 30 ​min, which is 2.16 times than pure Bi2WO6. It can be proved by XPS that the enhanced visible light performance of the composite is due to the photogenerated electrons and holes of MOF-5 flow to the conduction band and valence band of the flower-shaped Bi2WO6, reducing the recombination rate of photogenerated electron-hole pairs. Compared with the flower-shaped Bi2WO6, the specific surface area of composite was also improved, increasing the contact between the active sites and the dye molecules on the Bi2WO6 nanosheets. In addition, the cycle experiment shows that composite material has excellent stability.