Novel H3PW12O40/TiO2-g-C3N4 type-II heterojunction photocatalyst with enhanced visible-light photocatalytic properties

Abstract

A type-II heterojunction photocatalyst H3PW12O40/TiO2-g-C3N4 is obtained by ultrasonic method. The structure, morphology and optical property of the composites are studied by a series of characterizations. 20 wt.% H3PW12O40/TiO2-g-C3N4, the optimum composite, has superior photocatalytic efficiency for degrading rhodamine B (RhB) and p-nitrophenol (PNP) under visible light irradiation. The photocatalytic performance improvement of H3PW12O40/TiO2-g-C3N4 ternary composite material is ascribed to enhanced adsorption capacity of organic contaminants and efficient separation of photoinduced carriers. Furthermore, we can conclude that h+, O2−, and OH are the major active substances in the photocatalytic degradation process, which further provides the evidence for superior photocatalytic activity of H3PW12O40/TiO2-g-C3N4 composite material compared to bare g-C3N4. The H3PW12O40/TiO2-g-C3N4 composite displays excellent stability and recyclability, which can be reused for four times with only slight inactivation. Overall, this work puts forward a new direction for the fabrication g-C3N4-based visible-light-driven photocatalytic composite materials.