Preparation of Co doped TiO2 nano thin films by Sol Gel technique and photocatalytic studies of prepared films in tannery effluent

Abstract Simple dip and drive deposition unit for the preparation of thin films was designed and fabricated indigenously. TiO 2 nano thin films were prepared using the fabricated unit with different amount of dopants (5%, 10% and 15% of Co). The films were annealed at 550 °C using muffle furnace for one hour and allowed to cool till room temperature. The structural and composition of the thin films were analyzed using XRD and EDAX measurements. The X-ray diffraction peaks revealed that the films exhibit anatase crystalline structure. The composition of the film is confirmed as TiO 2 with trace of Co from the percentage of constituents in EADX results. The optical properties of the films were studied by using spectrophotometer with wavelength range of 190 nm to 2500 nm. The nature of the band gap is direct and it is nearly 3.4 eV. The surface morphology of the films was studied using AFM, SEM and TEM analysis. The films are identified that they are made out of nano particles of size below 25 nm. The films are found to be defect free and they are excellent films for photocatalytic studies. The films (without and with Co doped) were dipped in tannery effluent with different time intervals (1–3 h). The concentration of carbonate, chloride and sulphate present in the remaining effluent were analyzed by conventional methods. It is found that as percentage of dopant increases, the catalytic activity increases.