CO2 induced template approach to fabricate the porous C/CdS visible photocatalyst with superior activity and stability

Abstract

Porous C/CdS photocatalyst was fabricated facilely through novel CO2 mediated ethanol solvent without using any additional porous template. The unique features of CO2 mediated medium such as low viscosity, low surface tension and high diffusivity were beneficial to the uniform carbon coating on CdS surface. For the photocatalytic degradation of pollutants of RhB dye, phenol and dimethyl phthalate, the porous C/CdS catalyst prepared in the presence of CO2 (denoted as C/CdS-CO2) exhibited more excellent catalytic performance and stability under visible light than pure CdS and the reference C/CdS-E synthesized in ethanol without CO2 presence. The remarkable enhancements of photocatalytic activity and stability were ascribed to the multifunctional roles of the porous carbon coated CdS composites. Due to the uniform porous C coating layer, the adsorption capability to organic pollutants was enriched, the absorption to visible light was enhanced, the separation efficiency of photoinduced charges was accelerated, the photocorrosion of CdS and the toxicity leaching of Cd2+ were inhibited, which integrally contributed to the enhanced catalytic activity and stability of the C/CdS-CO2 composites. Besides, a possible photodegradation process for the pollutants over porous C/CdS-CO2 composites was tentatively proposed based on the experimental results.