Fabrication of self-cleaning photocatalytic durable building coating based on WO3-TNs/PDMS and NO degradation performance

Practical significance in terms of the long-term effective application of photocatalytic coatings is greatly challenged by its easy pollution and poor self-cleaning performance. In this paper, a self-cleaning photocatalytic WO3-TiO2 nanorod (MWT) /PDMS building coating (MWT coating) was prepared by spraying methods. The surface hierarchical structure fabricated by MWT and PDMS was a crux to construct a superhydrophobic surface, which endowed MWT coating with self-cleaning performance. Besides, the MWT coating exhibited prominent durability and antifouling property after 450 d practical application of the external wall. The excellent self-cleaning property of the coating was confirmed by the removal and resistance to the adhesion of powder particles. Meanwhile, the photocatalytic properties of MWT endowed MWT coating with the ability to degrade organic pollutants on the surface. The color difference of the coating polluted by methyl red was only 1.18 and 4.77 after 24 h UV and visible irradiation, respectively. This mutual benefit effect of self-cleaning and photocatalysis was also reflected in the degradation of NO. In the first five cycles, the degradation efficiency of NO decreased by 4.74% gradually under visible light due to the adhesion of oxidation products, and most of the MWT on the coating surface was regenerated after flushing, the PCD efficiency increased by 3.71%. Furthermore, after 30 days of outdoor weathering test, the PCD efficiency of MWT coating decreased by 11.74% and 12.05% under UV and visible light, respectively, which lays a foundation for the long-term effectiveness of the MWT coating in the process of use.