The thin layered graphitic carbon nitride (g-C3N4) was prepared by the thermal polymerization process with urea as the precursor. The layered heterostructure of graphitic carbon nitride-bismuth oxyiodide (g-C3N4/BiOI) was constructed by the in-situ synthetization of bismuth oxyiodide (BiOI) on the surface of the thin layered g-C3N4. The morphology, specific surface area, crystal structure, molecular structure, light absorption properties, and surface properties were characterized by TEM, BET, XRD, FT-IR, UV-Vis DRS, and XPS, respectively. The disinfection performance of the synthesized catalysts under visible light irradiation was investigated. The antibacterial mechanism of g-C3N4/BiOI in the photocatalytic process was further revealed by the capture of sacrificial agents. The results indicate that the prepared sample has a layered heterojunction structure with a specific surface area of 63 m2·g-1 and its light absorption side can obtain 600 nm. The results of the photocatalytic activity test indicate that g-C3N4/BiOI can kill bacteria within 4 h, which is significantly higher than that of g-C3N4 and BiOI. The main active species of g-C3N4/BiOI in the photocatalytic process can be attributed to the photogenerated holes.
Keywords: antibacterial; bismuth iodide; carbon nitride; heterostructures; photocatalysis.