Amorphous nanostructured TiO₂-SiO₂ composite coatings with visible light photocatalytic activity

In this study, amorphous nanostructured TiO₂-SiO₂ composite coatings were synthesized using a glycerol-templated sol-gel method to enhance visible light photocatalytic performance. The coatings were applied to soda-lime glass substrates via dip-coating and annealed at 300°C and 500°C. Structural and optical properties were characterized using X-ray diffraction, scanning electron microscopy, and ultraviolet–visible–near-infrared spectroscopy. The results indicated that the coatings maintained their amorphous structure post-annealing. Photocatalytic efficiency was evaluated through methylene blue degradation under artificial daylight, revealing significantly enhanced photocatalytic activity compared to the reference sample. Wettability tests confirmed that ultraviolet irradiation improved the hydrophilic properties of the coatings. These results suggest that amorphous TiO₂-SiO₂ composite coatings hold great potential for photocatalytic applications under visible light and can be optimized for environmentally sustainable technologies.