Hierarchical architectures of ZnS–In2S3 solid solution onto TiO2 nanofibers with high visible-light photocatalytic activity

Abstract

A unique hierarchical architecture of ZnS–In2S3 solid solution nanostructures onto TiO2 nanofibers (TiO2@ZnS–In2S3) has been successfully fabricated by simple hydrothermal method. The ZnS–In2S3 solid solution nanostructures exhibit a diversity of morphologies: nanosheet, nanorod and nanoparticle. The porous TiO2 nanofiber templates effectively inhibit the aggregation growth of ZnS–In2S3 solid solution. The formation of ZnS–In2S3 solid solution is proved by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) and the intimate contact between TiO2 nanofibers and ZnS–In2S3 solid solution favors fast transfer of photogenerated electrons. The trinary TiO2@ZnS–In2S3 heterostructures exhibit high adsorption capacity and visible light photocatalytic activity for the degradation of rhodamine B dye (RhB), remarkably superior to pure TiO2 nanofibers or binary structures (ZnS/TiO2 nanofibers, In2S3/TiO2 nanofibers and ZnS–In2S3 solid solution). Under visible light irradiation the RhB photocatalytic degradation rate over TiO2@ZnS–In2S3 heterostructures is about 16.7, 12.5, 6.3, 5.9, and 2.2times that over pure TiO2 nanofibers, ZnS nanoparticles, In2S3/TiO2 nanofibers, ZnS/TiO2 nanofibers, and ZnS-In2S3 solid solution, respectively. Furthermore, the TiO2@ZnS–In2S3 heterostructures show highly stable recycling performance.