Fe doped TiO 2 photocatalyst for the removal of As(III) under visible radiation and its potential application on the treatment of As-contaminated groundwater

Abstract The Fe doped TiO2 catalyst was evaluated under visible radiation for As(III) removal. The TiO2–Fe was synthesized by sol–gel technique at 0.0, 1.0, 2.5, 5.0 and 10.0 wt% iron doping concentrations. The semiconductors were characterized by X-ray diffraction, diffuse reflectance UV–vis, Raman spectroscopy, nitrogen physisorption, SEM–EDS and potentiometric titration for point of zero charge determination. The photocatalytic oxidation of As(III) was assessed in aqueous suspension contained 5 mg L−1 As(III) at pH 7 with 0.25 g L−1 catalyst loading. The incorporation of iron ions in TiO2 lattice extended the absorption to visible light region and create surface oxygen vacancies which favor photocatalytic oxidation reaction of As(III) using a small doping amount of Fe (1.0 wt%) in TiO2 powder. Additionally, TiO2–Fe 1.0 showed the highest adsorption capacity for As(V) removal compared to sol–gel TiO2 and P25 indicating that this catalyst is a promising material for As contaminated groundwater treatment.