Preparation, characterization of Bi 3 O 4 Cl/g-C 3 N 4 composite and its photocatalytic activity in dye degradation

This paper presents a novel composite photocatalyst Bi3O4Cl/g-C3N4 composite which was synthesized by a simple mixing and calcination method. The synthesized composite was applied in photocatalytic degradation of rhodamine B solution under visible light irradiation. Results indicated that the Bi3O4Cl/g-C3N4 showed higher activity than pure g-C3N4 or Bi3O4Cl. The optimal sample presents a degradation rate of 0.019 min−1, which is 1.9 and 3.8 times of Bi3O4Cl and g-C3N4, respectively. Various techniques including thermogravimetric analysis (TG), N2 adsorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence spectroscopy (PL) were applied to investigate the characters of the composite and reveal the origin of the high photocatalytic activity. It is found that the coupling of Bi3O4Cl on g-C3N4 slightly increased the BET surface area of the photocatalyst. However, the main reason for the enhanced photoactivity could be ascribed to the synergetic effect between Bi3O4Cl and g-C3N4 in separating electron and hole pairs.