Preparation of novel 0D/2D Ag2WO4/WO3 Step-scheme heterojunction with effective interfacial charges transfer for photocatalytic contaminants degradation and mechanism insight

Abstract

The efficient photo-induced charges transfer/separation plays a critical role in enhancing photocatalytic performance of WO3. Herein, the novel visible-light-driven 0D/2D Ag2WO4/WO3 Step-scheme (S-scheme) heterojunction photocatalysts are synthesized by a facile hydrothermal method following with an in situ precipitation process. The special two-dimensional structure of WO3 not only acts as a suitable supporter for Ag2WO4 nanoparticles, but also shortens the transfer route of photo-induced charges. More importantly, the formed internal electric field as well as the band edge bending at the interface of Ag2WO4 and WO3 can further induce charges separation and retain the strong oxidation ability of holes on the VB of WO3. As a result, the obtained 0D/2D Ag2WO4/WO3 S-scheme heterojunction shows an excellent photocatalytic performance towards the degradation of oxytetracycline (OTC) and typical dyes, respectively. The specific degradation route based on the main intermediates of OTC and the possible mechanisms for this S-scheme heterojunction system are also investigated and discussed. This work provides the new insights into design of novel WO3-based S-scheme heterojunction photocatalysts for high-efficient antibiotic and dye degradation.