Construction of Z-scheme Bi12O15Cl6/SnO2−x heterojunction for enhanced photocatalytic degradation of dyes and antibiosis

Abstract

It is still a great challenge to design efficient and stable photocatalysts to effectively remove organic pollution in water. A new type Bi12O15Cl6/SnO2−x Z-scheme heterojunction was successfully constructed. The best sample 30% Bi12O15Cl6/SnO2−x can degrade 86.7% TC within 90 min and 99.7% RhB within 75 min under LED light. The morphology, structure, optical and electrochemical properties of the photocatalyst were characterized by using different testing techniques. Efficient photoinduced charge transfer and separation efficiency was confirmed by photocurrent and electrochemical impedance spectra (EIS) in Bi12O15Cl6/SnO2−x structure. The active substances, intermediate product and photodegradation pathway in degradation process were revealed by capture test and mass spectrometry (MS) measurement. In photocatalytic process, h+, •O2− and •OH are the main active species, and h+ is the most important active substance. In addition, the photocatalytic mechanism of charge separation is also proposed, which provides a new opportunity for the construction of photocatalysts and the degradation of organic pollutants in the water environment.