Interfacial chemical bond and oxygen vacancies modulated Mo2S3/BiOBr high-low junctions for enhanced photocatalysis gatifloxacin degradation

Abstract

Insufficient light absorption and rapid recombination of photogenerated charges are considered to be the main obstacles limiting the efficiency of photocatalytic degradation of organic pollutants. In this study, a novel Mo2S3/BiOBr high-low junction was constructed by coupling narrow bandgap Mo2S3 to improve the light absorption capacity of BiOBr and enhance the utilization of photogenerated charges. Under simulated visible light irradiation, the optimised Mo2S3/BiOBr-6% high-low junction (90.1%) exhibited higher degradation efficiency of gatifloxacin compared to BiOBr (74.9%) and Mo2S3 (72.4%). The improved photocatalytic activity is mainly attributed to the interfacial chemical bonding and the formation of high-low junctions facilitating the rapid transfer of photogenerated charges between semiconductors, resulting in effective separation of photogenerated charges. In addition, the abundant oxygen vacancies in Mo2S3/BiOBr can act as electron traps to trap electrons and effectively reduce the photogenerated charge complexation. This study provides new perspectives for the construction of high-low junctions with interfacial chemical bonds and abundant oxygen vacancies and their use in the photocatalytic degradation of organic pollutants.