Catalytic performance of CuO/g-C₃N₄ composites for carbamazepine degradation

In this study, CuO/g-C₃N₄ composites were prepared by a calcination method, and were characterized by Scanning Electron Microscope (SEM)-Energy Dispersive Spectrometer (EDS), Fourier Transform Infrared spectroscopy (FT-IR), X-Ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) to analyze the surface morphology, crystal structure and valence state of CuO/g-C₃N₄, respectively. Carbamazepine was selected as the target pollutant to explore the catalytic performance of CuO/g-C₃N₄ composites in Fenton-like systems. The results show that when the initial concentration of CBZ is 20 mg/L, Cu composite amount is 7%, CuO/g-C₃N₄ dosage is 2 g/L and H₂O₂ dosage is 147 mmol/L, the removal rate of CBZ is the highest, which is about 96.59%. The Fenton-like reaction is not limited by solution pH, and the catalyst presents good stability. After five cycles, the removal rate of CBZ is still as high as 94.23%. ∙OH and ¹O₂ are the main active species detected in the catalytic process. The electron exchanges between CuO/g-C₃N₄ and H₂O₂ lead to the continuous occurrence of Cu (II)/Cu (I) redox process, which in turn decompose H₂O₂ to produce a large number of active groups to attack CBZ molecules and promote their degradation.