关键词: B掺杂C₃N₅复合材料, 自清洁涂层, 光催化, NO去除

Abstract:

In order to solve the problem of NO accumulation in automobile exhaust gas caused by poor air circulation in the tunnel，resulting in environmental pollution，B-doping nitrogen-rich carbon nitride（B/C₃N₅） composites were prepared by evaporation solvent in-situ thermal polymerization firstly.After B doping，B—N bonds were formed by replacing C atoms instead of replacing N atoms to form B—C bonds.After B doping，the efficient separation of photogenerated carriers was achieved，and the fluorescence lifetime of photogenerated carriers was extended，showing good visible light NO removal activity.The NO removal rate reached 97.36% within 2 h of visible light irradiation.A self-cleaning emulsion was synthesized by using epoxy resin E-44 as a film-forming matrix，B/C₃N₅ composite material as an active center，and low surface energy organic fluorosilicone as a functional monomer.The emulsion was sprayed onto the surface of concrete by spraying method to form a B/CN self-cleaning coating.The coating showed good superhydrophobic and oleophobic properties，and the static water contact angle of the 1.3% B/CN coating reached 160.2°.After 7 d of UV irradiation，the static water contact angle of the coating was still higher than 150° after 30 times of sandpaper abrasion and 15 times of water-oil impact，and the coating showed good durability.The self-cleaning coating showed excellent visible light NO removal activity.After 2 h of visible light irradiation，the 1.3% B/CN coating almost completely removed NO，and the removal rate reached 99.98%.After 5 cycles of use，the NO removal activity was still higher than 96.00%，which was suitable for the degradation of harmful NO gas from automobile exhaust on the inner wall of tunnel concrete.

Key words: B-doped C₃N₅ composites, self-cleaning coating, photocatalysis, NO removal