Facile construction of 3D hierarchical flower-like Ag2WO4/Bi2WO6 Z-scheme heterojunction photocatalyst with enhanced visible light photocatalytic activity

Abstract

A novel Z-scheme flower-like Ag2WO4/Bi2WO6 (AWO/BWO) photocatalyst with excellent photocatalytic activity for the contaminant degradation was successfully fabricated through a facile hydrothermal-precipitation method. Various characterization techniques and electrochemical measurements were exploited to study the morphology, structure, photoelectrical property of the photocatalyst. The photocatalytic efficiency for rhodamine B (RhB) degradation over the 3 wt% AWO/BWO composite was nearly 100% within 150 min under visible light, which was 11.5 and 1.5 times higher than pure AWO and BWO. The enhanced photocatalytic performance was attributed to the direct Z-scheme heterojunction, which not only achieved high separation efficiency of photogenerated electrons and holes but also retained strong redox capability of the composite. In addition, excellent stability and recyclability of AWO/BWO composites verified the photocatalyst was suitable for practical wastewater purification. Radical trapping experiment revealed that the dominant reactive species participating in the RhB degradation were superoxide radical(O2–) and holes (h+). Furthermore, a possible mechanism for RhB degradation and charge carriers transfer path was proposed on the basis of experiment results. This work offers new insights into the construction of efficient Bi-based photocatalyst with Z-scheme heterojunction, and exhibits its potential application in the field of environmental remediation.