Novel AgCl nanoparticles coupling with PbBiO2Br nanosheets for green and efficient degradation of antibiotic oxytetracycline hydrochloride under visible-light irradiation

Abstract

In this work, novel Ag/AgCl/PbBiO2Br photocatalysts were synthesized via a hydrothermal and in situ photoreaction method. The microstructure, morphology, composition, electrochemical, and optical properties of the synthesized catalysts were investigated by multiple techniques. The obtained Ag/AgCl, PbBiO2Br, and Ag/AgCl/PbBiO2Br composites were evaluated via degradation of oxytetracycline (OTC) hydrochloride antibiotic under visible-light irradiation. The results show that the Ag/AgCl/PbBiO2Br composites are composed of Ag/AgCl nanoparticles (NPs) and PbBiO2Br nanosheets. The Ag/AgCl/PbBiO2Br (20.4%) composite exhibits the highest visible-light absorption and best photogenerated charge separation efficiency. The photocatalytic degradation experiments show that all Ag/AgCl/PbBiO2Br composites exhibit an enhanced degradation activity under visible-light irradiation, and maintain good stability in the photocatalytic process. The Ag/AgCl/PbBiO2Br (20.4%) composite has the highest degradation activity, which is 1.82 and 2.11 times higher than that of Ag/AgCl and PbBiO2Br, respectively. The enhanced photocatalytic activity of Ag/AgCl/PbBiO2Br can be mainly attributed to the fact that the loading of Ag NPs on the surface of the AgCl promotes the separation efficiency of photoinduced charge and enhance the visible-light absorption. Additionally, active species trapping experiments confirm that superoxide radicals ( $${\mathbf{ \cdot }}{\text{O}}_{2}^{ - }$$ ), Cl0 and holes (h+) play an very important role in the degradation process.