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

Abstract

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.