Construction of g-C3N4/Bi4O5I2 heterojunction via the solvothermal method for the purification of eutrophic water

Abstract Heterojunction photocatalysts of g-C3N4/Bi4O5I2 were designed through the solvothermal method. A series of characterizations were used to analyze the structure, morphology, and optical and electronic characteristics of g-C3N4/Bi4O5I2 composite. Bi4O5I2 was successfully dispersed on the surface of g-C3N4. The 3 wt%-g-C3N4/Bi4O5I2 catalyst had the highest photocatalytic activity in eutrophic water. The degradation efficiency of chemical oxygen demand (CODMn), total nitrogen (TN), and chlorophyll a (Chl-a) was as high as 90.1%, 60.2%, and 66.1%, respectively. Based on the band structure analysis, the purification can be attributed to the transfer and separation of holes (h+) and electrons (e−) between g-C3N4 and Bi4O5I2.