g-C₃N₄/TiO₂ hybrid film on the metal surface, a cheap and efficient sunlight active photoelectrochemical anticorrosion coating

A solar light active photoelectrochemical anticorrosion paint was prepared by dispersing g-C₃N₄ nanomaterial in 0.05 M TiO(Acac)₂ solution. The paint can form uniform film on the metal surface after paralysis, which can provide effective cathodic protection for 304 SS under visible light irradiation. UV–Vis, Powder XRD, IR and EDS characterization identified that the film was composed by g-C₃N₄ and amorphous TiO₂; After coating the g-C₃N₄/TiO₂ film, which has a thickness around 12 um as shown by SEM, a photo-potential up to 0.20 V was observed for the metal specimen under visible light illumination (30mW/cm²) in 3% NaCl solution. The photo-potential can be accumulated with the irradiation time and held for many hours after removing the light illumination. Effective full-day cathodic protection for 304 SS can be provided by this g-C₃N₄/TiO₂ coating.