Novel Bi2O2Se/BiOCl with high visible light photocatalytic activity for environmental remediation: Effective layer to layer interfacial charge transfer based on heterojunction

Abstract

The photocatalytic activity of promising layered structure BiOX (X = Cl, Br, I) is limited by the low carrier mobility and charge transfer based on heterojunction. Hereon, we reported that Bi2O2Se with the same layered structure, high carrier mobility and broad spectrum absorption was used to composited with BiOCl to obtain effective layer to layer interfacial charge transfer and high photocatalytic activity under visible light. Bi2O2Se/BiOCl were synthesized via ion exchange method in precursor of Bi2O2Se. 25-Bi2O2Se/BiOCl shows the optimal photocatalytic removal activity of methyl blue (MB) and Cr (VI), which was higher than that of pure BiOCl and Bi2O2Se. The analysis of morphology revealed the in-growth mechanism of Bi2O2Se/BiOCl. A strong interaction between the same layer structure Bi2O2Se and BiOCl was proved by detailed analysis of XPS and valence charge density. Transient photocurrent responses and energy-level indicated the sensitized electrons of Bi2O2Se can be injected into BiOCl effectively and produce H2O2. We believe layer structure Bi2O2Se can be candidate co-catalyst to expand photocatalytic activity of layer structure semiconductor catalysts in the visible and infrared regions, especially, for the same layered bismuth compounds.