Synthesis of CPVC-modified SnS2/TiO2 composite with improved visible light-driven photocatalysis

Abstract

Synthesis of heterojunctions is very effective in increasing the photocatalytic activity of photocatalysts. Considering conjugated polyvinyl chloride derivative (CPVC) is capable of constituting heterojunctions with both SnS2 and TiO2, this study used CPVC to modify SnS2/TiO2 composite to develop a new high-efficiency visible light-driven ternary photocatalyst (CPVC/SnS2/TiO2). CPVC/SnS2/TiO2 was synthesized by a convenient and practical method, and its composition and structure were characterized using many means. The photocatalytic tests manifested that CPVC/SnS2/TiO2 not only had higher activity than TiO2/SnS2 and SnS2 in photocatalytic reduction of aqueous Cr(VI), but also was efficient in photocatalytic degradation of methylene blue under visible light irradiation. Besides, the effect of the dosage of CPVC/SnS2/TiO2 on its photocatalytic reduction of Cr(VI) was investigated. Also, the photocatalytic improvement mechanism of CPVC/SnS2/TiO2 was put forward, based on the results of the electrochemical impedance, transient photocurrent response and energy band structure measurements.