Construction of La2O3/AgCl S-scheme heterojunction with interfacial chemical bond for efficient photocatalytic degradation of bisphenol A

Abstract

The formation of interfacial chemical bonds in S-scheme heterostructure is a crucial factor to realize efficient interfacial charge transfer. High-energy mechanical ball-milling is an effective method to form interfacial chemical bonds. In this work, an S-scheme La2O3/AgCl heterojunction catalyst was designed and prepared by ball-milling method. XPS, FTIR and Raman measurements showed that La-Cl chemical bond was formed at the interface of La2O3 and AgCl and an S-scheme charge transfer path mechanism existed in the La2O3/AgCl composite. The results of electrochemistry, photo-electrochemistry, capture experiments, free radical measurement and EPR verified that the S-scheme heterojunction and the interfacial La-Cl bond significantly accelerated the charge transfer rate between La2O3 and AgCl, and enhanced the photocatalytic capability of the composite catalysts. The degradation rate of bisphenol A by La2O3/AgCl heterojunction composite (LA50) reached 99 % in 20 min, and it also had excellent anti-interference ability and cycling stability. The toxicity of the degradation intermediates of bisphenol A was much less than itself, as calculated by TEST simulation. This work provided a promising strategy for improving the performance of S-scheme heterojunction catalysts by introducing interfacial chemical bonds as charge transfer channels.