CQDs/g-C₃N₄的制备及其光催化降解四环素性能

Graphite phase carbon nitride (g-C₃N₄) was synthesized by calcination of melamine, carbon quantum dots (CQDs) were prepared from citric acid and carbamide. Then the CQDs/g-C₃N₄ composite photocatalytic materials were prepared by hydrothermal method. The morphology and structure of these materials were characterized by FESEM, FETEM, XRD, XPS and UV-VIS. Then, the performance and mechanism of tetracycline hydrochloride degradation by CQDs/g-C₃N₄ in visible light were studied. The results showed that CQDs loading enhanced the visible light absorption and photocatalytic activity of the materials. Furthermore, the degradation rate of the tetracycline hydrochloride in aqueous solution by CQDs/g-C₃N₄ reached 99% after 110 min visible light irradiation at CQDs/g-C₃N₄ dosage of 0.3 g and pH=7. In addition, CQDs/g-C₃N₄ composite material had good stability and recycling ability. The photocatalytic reaction of CQDs/g-C₃N₄ composite material was dominated by ·OH and H⁺, and the introduction of CQDs helped the migration and separation of the carriers, thereby improving the efficiency of the photocatalytic degradation of tetracycline hydrochloride.