Fe doped TiO2 photocatalyst for the removal of As(III) under visible radiation and its potential application on the treatment of As-contaminated groundwater

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. (C) 2015 Elsevier Ltd. All rights reserved.