Design and preparation of TiO₂-based environmentally stable photocatalytic self-cleaning coatings

Combining photocatalytic activity with superhydrophobicity, on the one hand, the surface superhydrophobicity can be utilized to carry away pollutants through water droplets, and on the other hand, photocatalysis can degrade organic pollutants and maintain the superhydrophobicity of the materials. A robust and wear-resistant PMHS/TBT-Quartz Sand-TiO₂ photocatalytic self-cleaning film-forming coating was prepared by constructing a micro- and nano-scrubber structure with Quartz Sand made from cave slag in synergy with TiO₂, and using poly(methylhydrosiloxane) (PMHS) and tetrabutyl titanate (TBT) as the low-surface-energy substances. The results show that the contact angle of the coating is 154.4°, and the rolling angle is less than 10°. TiO₂ is effectively loaded onto the surface of quartz sand, and an excellent micro and nano rough structure is constructed. The coating has excellent photocatalytic activity, which can degrade small organic molecules on the surface to remove nitrogen oxides in the air. In addition, the coating remains environmentally stable after continuous friction damage, long-term UV exposure, freeze-thaw cycles and other forms of damage.