Photocatalytic performance of BiVO4/RGO composite for degradation of Orange II under visible light

A simple hydrothermal method was employed to synthesize BiVO 4 supported on reduced graphene oxide (BiVO 4 /RGO) composite photocatalyst to enhance photocatalytic activity of BiVO 4 for degradation of dye wastewater under visible light. The prepared photocatalysts were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-Vis DRS and photocurrent measurements. The photocatalytic performances of the BiVO 4 /RGO composite were evaluated by degradation of Orange II (AO7) under visible light irradiation (λ > 420 nm). A series of experiments were carried out to evaluate the effects of various factors on removal efficiency of AO7. The results show that the BiVO 4 /RGO composite exhibited much higher photocatalytic activity than pure BiVO 4 . The highest removal efficiency of AO7 was obtained, and reach 100% after 150 min when the doping content, pH value, catalyst dosage was GB30 (30 mg of GO corresponds to 1 mmol of BiVO 4 ), pH = 9 and 200 mg, respectively. The free radical trapping experiments show that • O 2 - played the most important role in the degradation of AO7. The enhanced catalytic activity of the BiVO 4 /RGO composite can be attributed to the RGO. As an electron acceptor and transporter, RGO can effectively promote charge transfer in composite and inhibit the recombination of photo-induced electron-hole pairs.