Synthesis, optical and photocatalysis property of corn-like ZnO/ZnS heterojunction with a certain lattice defects.

Abstract

In order to greatly improve the photocatalytic properties, corn-like ZnO/ZnS heterojunctions with a particle size of about 60-71nm have been synthesized by the solvothermal method and the subsequent sulfuration process. A declining trend is found for the specific surface area with increasing sulfuration time. The corn-like ZnO/ZnS heterojunctions exhibit good photocatalytic properties. With increasing sulfuration time, the degradation rate increases first and then decreases. The best degradation rate is observed for the heterojunction sulfurated for 90min. The strong broad luminescence band is extremely beneficial to the absorption of visible light by multiphoton process. In addition, the energy transfer from ZnS to ZnO contributes to charge separation, forming a type-II heterojunction mechanism. After one cycle of photocatalytic process, except that corns become more broken, variation of particle size and shape is very small. The degradation speed of RhB after a second cycle of photocatalytic process is slower than the first one except when using the sample sulfurated for 360min.