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• A self-cleaning photocatalytic WO 3 -TiO 2 nanorod/PDMS coating. • The mutual benefit effect of self-cleaning and photocatalysis. • Visible-response photocatalytic NO degradation and self-cleaning performance. • The durable superhydrophobicity for external building wall. 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 WO 3 -TiO 2 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. [ABSTRACT FROM AUTHOR]

• A nitric oxide removal coating was constructed by loading doped TiO 2 /AC photocatalyst on waterborne acrylic coating. • Under visible light irradiation, the NO degradation efficiency of doped TiO 2 /AC coating was 45.8 % in 2 h, and only decreased by 5.8 % after 5 cycles. • UV stability of doped TiO 2 /AC coating was investigated, and the mechanism of improving UV stability was proposed. • After 42 d UV aging and single water flushing, the NO removal efficiency of doped TiO 2 /AC coating still reached 36.7 % and exhibited excellent UV stability. Based on the porous structure of activated carbon (AC) and the photo-oxidation behavior of TiO2, a visible-light-responsive photocatalytic coating with UV stability was constructed by loading Fe/N/Co-TiO2@AC (DTC) on waterborne acrylic coating. The DTC with adsorption and degradation synergistic effect was prepared by a simple mechanochemistry method and characterized by UV–vis, SEM, XRD, and BET. The nitric oxide (NO) removal efficiency of DTC was 51.6 % under visible light in 2 h. Besides, under the same conditions, the NO removal efficiency of the DTC coating still reached 45.8 %. Further, to investigate the UV stability of DTC coating, different coatings were prepared with the same dosage of DTC, TiO 2 @AC (TC), and TiO 2. The UV stability of the coatings was tested with a color difference, degree of chalking, adhesion strength, hardness, and impact resistance as evaluation indicators. The results showed that the DTC coating exhibited the best UV stability. The photooxidation of organic binder on the coating surface before and after aging was micro-characterized by SEM and FT-IR, and the UV stability improvement mechanism was revealed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A self-cleaning synergistic photocatalytic superamphiphobic coating. • The inhibition of NO 2 production during the NO photocatalytic degradation process. • Synergistic effect of self-cleaning and photocatalysis of photocatalytic coating. • A green NO photocatalytic degradation mechanism of photocatalytic coating. Multitudinous deleterious NO 2 will be produced in the process of NO photocatalytic degradation, which may cause serious secondary pollution. In this study, a self-cleaning synergistic photocatalytic coating was constructed by the simple spray method. The coating has excellent superamphiphobicity and NO degradation performance. In addition, the production of NO 2 in the process of NO degradation by photocatalytic superamphiphobic coating was inhibited, which indicated the greener photocatalytic process exhibited by this photocatalytic coating. Also, to clarify the inhibition of the coating on NO 2 , the NO degradation mechanism of the coating and photocatalyst was investigated by in situ IR, trapping test and EPR spectra, and the possible pathway of NO degradation was summarized. Combining the result of DFT calculation and degradation product analysis, the inhibition of NO 2 and"green" degradation mechanism of the self-cleaning synergistic photocatalytic coating was explored and proposed, which may provide some theoretical support for the "green" application of photocatalysis. [ABSTRACT FROM AUTHOR]

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. [Display omitted] • A WO 3 -TiO 2 nanorods/SiO 2 photocatalytic superamphiphobic coating. • The reasonable robustness and excellent superamphiphobicity. • The prominent degradation performance in high relative humidity environment. • A mechanism of improving the NO degradation efficiency. [ABSTRACT FROM AUTHOR]