Synthesis of Ag2CO3/Bi2WO6 heterojunctions with enhanced photocatalytic activity and cycling stability

摘要

Hierarchical Bi2WO6 nanoarchitectures with a size of 2-3 mmwere prepared via a facile microwave-assisted solution-phase reaction process. Monodisperse spherical Ag2CO3 nanoparticles with an average size of about 10 nm were deposited onto the surface of the Bi2WO6 nanoarchitectures to form a novel Ag2CO3/Bi2WO6 heterojunction structure through a facile in situ precipitation-deposition method. The obtained samples were characterized using XRD, XPS, SEM, TEM (HRTEM), UV-vis DRS and nitrogen adsorptiondesorption techniques. The photocatalytic evaluation demonstrates that the decoration with Ag2CO3 nanoparticles significantly enhances the photocatalytic activity of Bi2WO6 and the photocatalytic performance is greatly influenced by the content of deposited Ag2CO3. The 30 wt% Ag2CO3-loaded Bi2WO6 sample exhibited the highest photocatalytic activity for the degradation of rhodamine B (RhB) under visible light irradiation. Meanwhile, it also possesses excellent cycling stability and superior photocatalytic performance toward other pollutants. The dramatically enhanced photocatalytic activity and stability can be mainly ascribed to well-matched energy bands and heterojunctions between Ag2CO3 and Bi2WO6, which can effectively improve the separation of photo-induced electron-hole pairs at the heterojunction interfaces.