A novel hydrothermal induced BiVO4/g-C3N4 heterojunctions visible-light photocatalyst for effective elimination of aqueous organic pollutants

Abstract

In this report, a novel BiVO4/g-C3N4 heterojunction photocatalysts were developed through facile and one step hydrothermal route. Various characterization techniques such as X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM), Raman, UV–Visible diffuse reflectance (UV-DRS), Photoluminescence and Brunauer-Emmett-Teller (BET) analysis have been carried out to know the structural, optical and textural behavior of the pure BiVO4 and various BiVO4/g-C3N4 hybrid catalysts. The basic characterization results suggest that interaction between BiVO4 and g-C3N4 was confirmed and a heterojunction was formed on the surface of g-C3N4/BiVO4 composite, which enhanced the separation and transfer of photogenerated electron-hole pairs. Visible light induced photocatalytic degradation test was carried out for all the synthesized catalysts towards rhodamine B (RhB) and 4-chlorophenol (4-CP) dyes. Among the various composite catalysts, the 3:1 mass ratio of BiVO4/g-C3N4 (BVG3) catalyst achieves the optimum photocatalytic activity for the degradation of 4-CP, and reached 95.%, which is 3.7 times better than bare BiVO4 (25%). The hybrid catalyst has also delivered a high apparent constant (0.0821 min−1) and huge stability (loss only 2.25%). The improved photocatalytic mechanism was also discussed.