Abstract: Photocatalytic coating technology shows important application prospects in the field of NO treatment in tunnels due to its high efficiency environmental purification ability. A Bi₂O₂CO₃@C₃N₄ junction composite photocatalyst was prepared. Under simulated visible-light irradiation, the photocatalytic degradation efficiency of NO reached 35%, which was approximately 3 times higher than pure-phase Bi₂O₂CO₃. Exploring the mechanism of improving catalytic performance through PL, UV-Vis, electrochemical and other tests. Using epoxy resin (EP) as the film-forming matrix, a low-surface-energy modifier was introduced and a rough micro-nano structure was constructed. The coating was prepared by a one-step spraying method. The microstructure, chemical composition, and thermal stability of the coating were characterized by various testing techniques.The coating achieves a NO degradation efficiency of up to 33% under visible light. Surface dust removal tests demonstrate its excellent self-cleaning performance. After sandpaper abrasion, UV aging resistance, and acid-base-salt corrosion (12 h, 24 h, and 48 h), the coating maintains a contact angle with water and olive oil greater than 145°, indicating superior hydrophobicity, oleophobicity, and durability, making it suitable for NO catalytic degradation in tunnel environments.