A robust superhydrophobic coating based on I- doped Bi2O2CO3 for tunnel applications: Synergistic self-cleaning and NO removal

In response to the problem of nitrogen oxide pollution in tunnel environments, this study successfully prepared I - doped Bi 2 O 2 CO 3 photocatalyst I-BOC through solid-phase grinding method. The introduction of I - leads to a notable reduction in the bandgap of BOC, while also enhancing the specific surface area and pore volume, thereby facilitating the effective separation of photogenerated carriers. When exposed to visible light, I-BOC demonstrates a peak degradation efficiency of 58% for NO, and experiments involving free radical capture indicate that ·O 2 – is the primary active species, and explore the impact of the tunnel environment on the degradation efficiency of the catalyst. Additionally, epoxy resin served as the substrate for film formation, and 1H, 1H, 2H, 2H-perfluorodecyltrimethoxysilane (PFDTES) was incorporated as a low surface energy additive. A superhydrophobic photocatalytic self-cleaning coating (FBIE) characterized by a micro-nano rough structure was created using a one-step spraying technique. This coating showcases outstanding superhydrophobic properties and water contact angle exceeding 150°, along with excellent mechanical durability and chemical stability, achieving a visible light degradation efficiency of up to 65% for NO, and outstanding physical and chemical self-cleaning ability. By exploring the catalytic effects of I-BOC and FBIE coatings under different humidity conditions, the synergistic mechanism of coating photocatalysis and self-cleaning is revealed, providing broad application prospects for coatings in tunnel air purification.