Highly efficient visible light induced photoelectrochemical anticorrosion for 304 SS by Ni-doped TiO2

Ni-doped TiO2, which was fabricated via sol-gel method in the present work, possesses the best photoelectrochemical anticorrosion property for 304 stainless steel under visible light illumination when the Ni doping amount is 0.5% (Ti0.995Ni0.005O2). The Ni-doping leads to the extension of the photoresponse of TiO2 from ultraviolet to visible light. Ni is substitutionally doped in TiO2 matrix by substituting the Ti4+ lattice sites and the oxygen vacancy forms for Ti0.995Ni0.005O2. The oxygen vacancy promotes the transfer of photoinduced electrons, resulting in the increase of the photo-to-current conversion efficiency of TiO2 under visible light. Finally, the oxygen vacancy and Ni-doping efficiently enhance the photoelectrochemical anticorrosion property of TiO2 under visible light illumination.