Preparation of graphene/WO 3 /TiO 2 composite and its photocathodic protection performance for 304 stainless steel

Abstract Graphene/WO 3 /TiO 2 composite (RGO/WO 3 /TiO 2 ) was successfully fabricated via a two-step hydrothermal method. The structure, morphology and optical property of the as-prepared composite were characterized by X-ray powder diffraction, fourier transform infrared spectra, Raman spectra, transmission electron microscope, scanning electron microscope and ultraviolet-visible diffuse reflectance spectra, respectively. Results showed that the composite was incorporated by graphene nanosheets, WO 3 nanorods and TiO 2 nanoparticles. It exhibited favorable absorption ability in both UV and visible light region. The photocathodic protection performance for 304 stainless steel (304SS) was proven by photocurrent density, open circuit potential, Tafel polarization curves and electrochemical impedance spectroscopy. It was found that the composite could provide an efficient protection for 304SS under visible light irradiation and even in the dark compared to the pure TiO 2 . The electrode potentials negatively shifted to −760 mV under visible light. The possible photocathodic protection mechanism of the composite was also proposed.