In-situ growth UiO-66-NH2 on the Bi2WO6 to fabrication Z-scheme heterojunction with enhanced visible-light driven photocatalytic degradation performance

Abstract

Bi2WO6 has a great application prospect in the field of organic pollutants photodegradation. However, the development of Bi2WO6 photocatalyst has been limited by low specific surface area, weak hydrophilicity and high electron-hole recombination rate. Whereas studies applying MOFs as cocatalyst to overcome the above disadvantages are very limited. In this study, the Z-scheme photocatalysts of UiO-66-NH2/Bi2WO6 composites with UiO-66-NH2 growth on the surface of Bi2WO6 was prepared by in situ growth. Compared with pure UiO-66-NH2 and Bi2WO6, The composite of UiO-66-NH2/Bi2WO6 displayed higher photocatalytic activity for Rhodamine B (RhB) and phenol degradation under visible light. Comparatively, 0.125-UiO-66-NH2/Bi2WO6 behaved the best photocatalytic property. SEM, TEM and Water contact angles results revealed that integrating UiO-66-NH2 with Bi2WO6 could enhance the dispersion of UiO-66-NH2 and hydrophilic property of Bi2WO6. The photo-electrochemical studies indicated that the separation and transfer of photo-generated charge carriers can be efficiently improved via the interface of UiO-66-NH2 and Bi2WO6. Based on the experiments of free radical scavengers, a possible mechanism of degradation was suggested, which proved that ∙O2− and h+ are the main active substances. This Z-scheme photocatalysts will have application prospects in the environment remediation, and this strategy provides a new insight into construction of composites with strong interaction photocatalysts.