Efficient removal of the antibiotic Cefixime on Mg0.3Zn0.7O under solar light: kinetic and mechanism studies

• Published in: Environmental science and pollution research international 2022-10, Vol.29 (50), p.75512-75524
• Main Authors: Brahimi, Billal, Mekatel, Elhadj, Kenfoud, Hamza, Berrabah, Salah Eddine, Trari, Mohamed
• Format: Article
• Language: English
• Subjects: Antibiotics; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Catalysts; Cefixime; Contaminants; Crystallites; Crystals; Earth and Environmental Science; Ecotoxicology; Electrochemical analysis; Electrochemistry; Electron microscopes; Environment; Environmental Chemistry; Environmental Health; Environmental science; Forbidden bands; Mineralization; N-type semiconductors; Optical properties; Oxidation; pH effects; Photocatalysis; Photocatalysts; Photodegradation; Physicochemical properties; Research Article; Scanning electron microscopy; Scavenging; Silver chloride; Waste Water Technology; Water Management; Water Pollution Control; X ray analysis; X ray photoelectron spectroscopy; X-ray diffraction
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-022-20626-y

The heterogeneous photocatalysis is known to provide significant degradation and mineralization of emerging contaminants including antibiotics. For this, nanosized Mg 0.3 Zn 0.7 O (MZO) was prepared by nitrate route to be used as photocatalyst. The single-phase was confirmed by X-ray diffraction with a crystallite size of 33 nm. The morphology was visualized by scanning electron microscope/energy-dispersive X-ray analysis. The physicochemical properties were studied by the FTIR, XPS, and optical analyses. The diffuse reflectance gives a direct forbidden band of 3.26 eV. The electrochemical characterization showed an n -type semiconductor with a flat band of − 0.56 V Ag/AgCl . The photodegradation of Cefixime (CFX) was carried out under solar light; the operating parameters such as the catalyst dose, solution pH, and initial CFX concentration ( C o ) were optimized. The best performance occurs at neutral pH ~ 6 within 4 h with an abatement of 94% for an initial CFX concentration of 5 mg/L and MZO dose of 0.75 g/L. The photodegradation follows a first-order kinetic with an apparent rate constant of 0.012 min -1 . The effects of scavenging agents indicated the dominant role of hydroxyl • OH followed by the holes (h + ). The results showed the potentiality of MZO as an environmentally friendly photocatalyst for CFX photodegradation.