Improvement mechanism of NO photocatalytic degradation performance of self-cleaning synergistic photocatalytic coating under high humidity
Guanyu Liu, Huiyun Xia, Wenshuo Zhang, Lifang Song, Qiwei Chen, Yanhui Niu
Abstract
Photocatalytic coating has been widely studied as a promising material to remove air pollutants. However, the effectiveness and long-term effect of photocatalysis in high relative humidity environment is still the main challenge in this field. In this study, a fluorinated WO 3 -TiO 2 nanorods/SiO 2 epoxy photocatalytic superamphiphobic coating (FTSE coating) was prepared using a simple spraying method. The micromorphology and chemical composition of FTSE coating was characterized by SEM , EDS, FT-IR, XPS and TGA techniques. The advanced contact angle and hysteresis angle test show that the FTSE coating had excellent superamphiphobicity. The mechanical abrasions , corrosion resistance and UV aging tests show that the FTSE coating exhibited reasonable durability. Besides, the NO degradation efficiency of hydrophilic and superamphiphobic coatings with contact angles of 20.19°, 87.74°, 162.93° and 164.47° was tested in different humidity environment. The results showed that the superamphiphobic coating exhibited more superior photocatalytic degradation efficiency (84.02%) than the hydrophilic coating (51.38%) at a high relative humidity (RH=98%). Finally, FTSE coating exhibited prominent photocatalytic stability and the synergistic effect of photocatalysis and self-cleaning. After 30 d outdoor weathering test, the NO degradation efficiency decreased by 13.07% and recovered to the original level after flushing. The improvement mechanism of NO degradation performance was proposed based on the characteristics of superamphiphobic surface.