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

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 thorn 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 flowershaped 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.

Automated summary

In this study, a core-shell MOF-5/Bi2WO6 photocatalyst was successfully prepared by using Bi2WO6 as a carrier and a two-step hydrothermal method. A type-I heterojunction photocatalytic mechanism was proposed, and O2- and h thorn were identified as the main active substances. The 9% MOF-5/BWO catalyst exhibited the best degradation activity, achieving a 99.31% degradation of RhB in 30 minutes, which was 2.16 times higher than pure Bi2WO6. The enhanced visible light performance of the composite was attributed to the flow of photogenerated electrons and holes from MOF-5 to the conduction band and valence band of flower-shaped Bi2WO6. The composite also showed an increased specific surface area, improving the contact between active sites and dye molecules on the Bi2WO6 nanosheets. Additionally, the composite material exhibited excellent stability based on cycle experiments.