Preparation and performance of self-cleaning synergistic visible light catalytic coatings based on N-CQDs/Bi2WO6 for NO degradation

Due to the intensification of nitric oxide (NO) emissions caused by industrial development, visible light responsive photocatalysts have been selected and applied in building coatings as a new strategy. In this study, N-doped carbon quantum dots (N-CQDs)-Bi₂WO₆ (NBW) was prepared using an ethylene glycol-assisted solvothermal method. Various techniques, including XRD, FT-IR, SEM, were employed to analyze and characterize NBW. The photocatalytic performance and stability of NBW were evaluated, and the results showed that 52% of NO (Initial concentration: 600 ppb) were oxidized under visible light. NBW was dispersed in an ethyl acetate/polytetrafluoroethylene (PTFE)/polyvinylidene fluoride (PVDF) suspension and modified by 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PFDTES), to form an easy-to-spray coating referred to as CPFB. Due to the photocatalytic ability of NBW, CPFB oxidized 74% of NO under visible light and reduced the coloring of coating surfaces contaminated with methyl red. The superhydrophobicity of CPFB coating provided the foundation for its self-cleaning ability. In addition, CPFB exhibited hydrophobicity and photocatalytic performance even after tests such as photooxidation, water impact, and wear. Finally, the photocatalytic mechanism of CPFB self-cleaning coating was explored. The significance of CPFB lied in its ability to effectively combine self-cleaning, visible light-responsive photocatalysis, and durability in a single coating. This innovative approach may inspire the development of similar coatings for various applications.