Enhanced visible light absorption of Bi2WO6/SiO2 with abundant adsorbed oxygen for the degradation of organic pollutant

Abstract

Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants, but their stability and repeatability is not very good and requires high structural matching. Simply by nanosizing the pure Bi2WO6 (BWO) photocatalyst without constructing a heterojunction, there is a significant improvement in its performance, with an enhancement effect of about 2.3 times (99.43%). The high photocatalytic degradation efficiency of the material can be attributed to the enhanced light absorption effect brought by the three-dimensional inverse-opal structure SiO2 (IS) and the abundant surface adsorbed oxygen generated after the formation of Si–O–W bonds. In addition, the introduction of IS greatly increases the surface area of nanostructured BWO, which accelerates the charge transfer process, while the adsorbed oxygen promotes the participation of ·O2− in the photocatalytic reaction, thereby accelerating the consumption of photo-generated electrons and ultimately improving the separation of charge carriers. Furthermore, the matched photonic bandgap further improves the absorption and utilization of light of the material. In this work, we constructs Si–O–W bonds to obtain inverse-opal SiO2/Bi2WO6 with uniformly growth of pure phase nano BWO, which provides a feasible strategy for the preparation of high-performance pure-phase photocatalysts.