Phtotocatalytic Degradation of Methyelene Blue by Cu Doped TiO2 Thin Films under Visible Light Irradiation

Pure TiO2 and Copper doped TiO2 thin films of various concentrations (0.02–0.05 mol %) have been successfully deposited onto glass substrate by sol-gel dip coating technique and annealed at 400ºC for 3 hours. The XRD results showed the presence of anatase phase for all the films and the crystallite size decreases with increasing doping concentrations. The morphological observations and compositional analysis were recorded with SEM and EDX. The UV-Visible study showed that the optical band gap energy decreases with increasing Cu content. It was also found that copper doping shifted the absorption edge of TiO2 toward a visible regime depicting the possible modification in the electronic band structure. The photocatalytic activity was evaluated by monitoring the degradation of methyelene blue under visible light illumination. It was found that the percentage of degradation was higher in 0.05mol% Cu-TiO2 when compared with other films. The efficiency of the Cu-TiO2 thin film was preserved even after the extended usage of the films which sustains the reusability nature of Cu-TiO2 films.