Directional Growth of Bi₂WO₆ with Highly Exposed Facets on 2D‐Co₃O₄ for different Properties under two Light Sources

Abstract

A composite of two or more materials usually results in enhanced specific properties. In this paper, a kind of composite material composed of Bi2WO6 with highly exposed {010} facets and 2D‐Co3O4 was prepared by a one‐pot reaction and then applied to decontaminate hydrocortisone in wastewater. The Bi2WO6/Co3O4 composite possessed a rose‐like surface microtopography self‐assembled from Bi2WO6 and Co3O4 nanosheets. The micro‐interface analysis showed that {110} facets of Co3O4 and {010} facets of Bi2WO6 were glued in situ and formed heterojunction. Additionally, the removal ability of hydrocortisone through Bi2WO6/Co3O4 varied under different light sources, which was 85.0% under ultraviolet light and 97.3% under visible light within 60 min. It was considered that Bi2WO6/Co3O4 was similar to a traditional heterojunction and the major reactive species was H2O2 under ultraviolet light, while it played a role as a Z‐scheme photocatalyst and the major reactive species was •OH under visible light. Finally, product analysis of hydrocortisone demonstrated that the dexter chain broke whatever under ultraviolet or visible light, but the breakage of parent nucleus appeared only under visible light. This research revealed the enhanced catalytic properties of p‐n heterojunction catalysts and indicated the specifically exposed facets are promising for organic contaminants in water.