Synthesis of g-C3N4/Ag3VO4 composites with enhanced photocatalytic activity under visible light irradiation

• The g-C3N4/Ag3VO4 composites exhibited higher photocatalytic activity than the individual Ag3VO4.
• The stability of 5 wt% g-C3N4/Ag3VO4 was higher than that of the pure Ag3VO4 after cycling experiments.
• The holes were the main active oxidizing species which leaded to the high photo-oxidation efficiency.

The g-C3N4/Ag3VO4 hybrid photocatalysts were developed to study the photocatalytic activity under visible light irradiation. The samples were characterized by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS). The photocatalytic activity of g-C3N4/Ag3VO4 composites for the photodegradation of methylene blue (MB) and rhodamine B (RhB) under visible light irradiation was much higher than that of the pure g-C3N4 and Ag3VO4. The kinetics of the g-C3N4/Ag3VO4 composites were proposed to investigate the intervened effects of g-C3N4 to Ag3VO4 on the promotion of photocatalytic property. The photocurrents were measured to study the photoinduced charge-transfer properties of the g-C3N4/Ag3VO4 composites. The possible photocatalytic mechanism of the composites was proposed by implementing a series of radical trapping experiments to guide the further improvement of their photocatalytic activity. It is suggested that the outstanding photocatalytic activity of g-C3N4/Ag3VO4 composites was ascribed to the separation of the photoinduced electron–hole pairs with the integration of g-C3N4 and Ag3VO4 from analyses above.