Degradation of tetracycline drug in aquatic environment by visible light active CuS/CdS photocatalyst

Photocatalysis is the best approach to degrade tetracycline antibiotic (TC) under sunlight. Hydrothermal approach was used to synthesize a potential CuS/CdS photocatalyst. The prepared catalysts were used to treat the TC in aquatic environment under visible light illumination. X-ray diffraction pattern confirmed that the CuS and CdS are in hexagonal structure, the corresponding planes are presented in the prepared CuS/CdS nanocomposite. High resolution scanning electron microscope images disclosed that the mixed morphologies of nanoplates and nanorods obtained in CuS/CdS nanocomposite. The synthesized CuS/CdS photocatalyst has absorption in visible region. The bandgap of CuS/CdS as calculated to be 2.30 eV. The CuS/CdS nanocomposite which exhibits high photocatalytic performance with degradation efficiency of 90% in 50 min, which was 2.3 and 1.4 times higher than that of CuS and CdS respectively. A series of radicals trapping experiment revealed that h+ and •O2- are the dominant active species during the degradation process. Additionally, a possible photocatalytic mechanism of the prepared CuS/CdS was also provided. The prepared CuS/CdS photocatalyst exhibits excellent photocatalytic stability even after four cycles, it reveals that the material has good chemical property. This result indicates that the synthesized CuS/CdS photocatalyst was favourable for the degradation of TC antibiotics in aquatic environments.