Development of highly transparent, superhydrophilic Sr and Ce Co-doped TiO₂ thin films with self-cleaning properties for potential application in solar panel surfaces

One of the most effective strategies for mitigating the long-term yield losses associated with solar panel dusting is applying self-cleaning transparent thin films to their outer surfaces. In this study, highly transparent superhydrophilic TiO₂ coatings doped with Sr and Ce were synthesized via sol-gel/dip coating technique to enhance their photocatalytic properties. Characterization of the thin films was conducted utilizing grazing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle (CA) measurement methodologies. Optical property analysis was performed via UV–Vis spectrophotometry. The anatase phase was the only crystalline phase present in the samples, according to the GIXRD pattern. SEM and AFM images revealed uniform particle distribution across the glass substrate, with TiO₂ and Sr,Ce-TiO₂ film particle sizes and surface roughness falling within the ranges of 20–30 nm and 40–50 nm, and 1.71 nm and 1.95 nm, respectively. Contact angle measurements demonstrated superhydrophilic properties with CA values below 5°. The photocatalytic activity was assessed through methylene blue degradation studies. The results indicated that co-doping TiO₂ with Sr and Ce enhanced the degradation efficiency from 42.2% to 66.2% and 18.3%–41.5% under UV and Vis lights, respectively. MB decomposition followed pseudo-first-order kinetics.