Microstructure regulation and performance optimization of porous ceramic supported NiS/CdS composite

Abstract

Porous Al₂O₃ ceramic-supported NiS/CdS composite was prepared by hydrothermal method with NiO as the template. The NiO template was fabricated with dip-calcinating technique. The effects of calcination temperature, Ni(NO₃)₂ concentration, hydrothermal temperature and reaction time on the microstructure, visible-light photocatalytic activity, and reusable property of supported NiS/CdS composite were investigated. The photocatalytic mechanism of NiS/CdS composite was studied. The results show that, the NiO template calcined at 300 °C with 1 mol L⁻¹ Ni(NO₃)₂ concentration is beneficial to providing more active sites and promoting the formation of NiS phase. The nano NiS/CdS composites distribute on the surface or in the lamellar pores of porous ceramic carrier. The supported NiS/CdS composite prepared at 180 °C soaking for 12 h achieves 99.3 % methyl orange solution degradation rate. The degradation rate of supported composite decreases from 99.3 % to 66.39 % after repeating four times. The formation of heterojunction between NiS and CdS is conducive to improving the bonding strength, loading amount, photocatalytic activity and reusability of the supported composite. The microstructure can be regulated and the performance can be improved through optimizing the process parameter.