The degradation of tetracycline by modified BiOCl nanosheets with carbon dots from the chlorella

In this study, chlorella was first used as the carbon source of Carbon dots (CDs) and further modified the BiOCl. Then, a novel photocatalyst Carbon dots/BiOCl (CBOC) was successfully synthesized. The morphology, crystal structure, chemical states and optical properties of the material were characterized by different techniques. Meanwhile, the energy band structure and density of states of CBOC2 composite were calculated based on density functional theory. In order to investigate the photocatalytic performance of the materials, the photodegradation of tetracycline was carried out under the simulated sunlight. The conditions of different materials, materials dosage and sample concentration were compared. About 99.5% tetracycline (10 mg/L) can be photodegraded by 15 mg CBOC2 in 75 min illumination with 52.2% mineralization rate. The material can be reused with high stability. The ·O2− is the main reactive species. The possible degradation pathways and mechanism of photocatalysis was discussed in detail. The CDs originated from chlorella has the large contribution in the photocatalysis. The work creates a new road of the application of chlorella in photocatalysis.