Highly photostable Zn-doped TiO2 thin film nanostructures for enhanced dye degradation deposited by sputtering method

Zn-doped TiO2 thin films were deposited on glass substrates using the RF sputtering method with various Zn-dopant concentrations at a substrate temperature of 300 °C. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), UV-Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) were used to analyze the crystal structure, surface morphology, transmittance, elemental composition, oxidation states, and degradation of the prepared thin films. The anatase phase of TiO2 was observed in the coated thin films. A maximum transmittance of ~77% and the lowest band gap of ~3.12 eV was achieved. The roughness of films increased with the Zn concentration, and a roughness of ~15.23 nm was observed. Photocatalytic degradation activity was tested using phenol red dye, and a maximum dye degradation of ~58% was achieved. In addition, no structural or surface chemical changes were seen in the thin film used for the photocatalytic activity, even after five cycles, which indicates that the films exhibit high photostability.