Assessment of High Transparency Nanocrystalline TiO₂ Thin Films and Their Photocatalytic Removal of Pollutant Dye

In this investigation, uniform, high transparency, high purity titanium dioxide thin films composed of densely packed nanometer sized grains have been successfully deposited on a borosilicate glass substrate. The crystalline phase of the TiO₂ thin films have been determined using X-ray diffraction (XRD) and Raman spectroscopy. The transmission and absorption spectra were characterized by UV-Vis spectroscopy. Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM) were also applied for morphology characterization of the thin film surface. The surface area was determined by Brunauer-Emmette and Teller analysis (BET). Under UV illumination, the film with the highest surface area, and most uniform distribution of grains and pore size, showed the highest removal efficiency for a common textile dye, Reactive Yellow 17. The apparent rate constant (k) was 1.57×10⁻² min⁻¹ and the half life (t _1/2) was 44.14 min⁻¹. The key advantage of thin film catalysts in water treatment is that they can be recycled many times without requiring special treatment.