Solid-Phase Microwave Reduction of WO3 by GO for Enhanced Synergistic Photo-Fenton Catalytic Degradation of Bisphenol A.

The synergistic photocatalytic Fenton reaction is a powerful advanced oxidation technique for the degradation of persistent organic pollutants. However, microwave-induced thermal effects on the formation of novel structures facilitating the photocatalytic degradation have been rarely reported. Herein, a two-step microwave thermal strategy was developed to synthesize a new hybrid catalyst comprising defective WO3-x nanowires coupled with reduced graphene oxides (rGOs). Conventionally, microwave methods could induce superhot spots on the GO surface, resulting in the site-specific crystallization and oriented growth of WO3. However, in the solid phase, localized microwave thermal effects could reduce the interfacial area between WO3 and rGO and enhance the bonding between them. As for the unique structure and surface properties, the synthesized catalyst enhanced the light absorption, promoted the interfacial charge separation, and increased the carrier density in the photocatalytic processes. In addition, surface formation of W4+ provided a new pathway for Fe3+/Fe2+ cycling which linked the photocatalytic reaction and the Fenton process. The optimized catalyst exhibited a remarkable performance in the degradation of bisphenol A with a ∼83% removal yield via a photo-Fenton route. These microwave-induced functionalities of materials for synergistic reactions could also give a new avenue to other photoelectrocatalytic fields and solar cells.