High photocatalytic activity of ZnS@Ag8SnS6 nanocomposites: Preparation and investigation

Abstract

Nanoscale Ag8SnS6 (ATS) and ZnS@ATS heterogeneous composites were synthesized by a stepwise heating method. The as-prepared ATS nanoparticles were mainly irregular polygons with crystal size ranging from 35 to 120 nm, and transformed to cotton shape particles when nano ZnS was added during the synthesis process. Photocatalytic properties of the as-prepared ATS, ZnS and ZnS@ATS were investigated using Methylene Blue solution as the target degradation. It is resulted that the rate constant of the catalysts first increases and then decreases with the content of ZnS in ZnS@ATS composites. In the optimal case of 0.5 mmol ZnS@ATS, rate constant of 0.7012 h−1 was achieved which is 7.3 times that of ZnS and 2.3 times that of ATS. The improvement mainly comes from enhancing separation and transfer efficiency of photogenerated electron-hole pairs at the grain boundaries of ZnS@ATS.