Enhanced photocatalytic degradation of antibiotic sulfamethoxazole by nanoparticles of ZnO in the presence of different surfactant types
摘要
Antibiotics are stable molecules and refractory to several degradation methods; therefore, they present an environmental problem after use. They persist in the aquatic environment, causing a risk to human health. Photocatalysis is a process widely used to degrade even the most refractory organic compounds. This work presents the photodegradation of sulfamethoxazole (SMX) in the presence of ZnO as a semiconductor. ZnO nanoparticles were prepared via an adapted sol–gel method utilizing ZnCl2 as a precursor and various surfactants, including cationic surfactants cetyltrimethylammonium bromide (CTAB) and Octadecyl trimethylammonium chloride (OTAC), the nonionic surfactant triblock copolymer Pluronic F127, and the zwitterionic surfactant sulfobetaine (C4H8O2S). Different characterization techniques were employed to analyze morphological, optical, and structural properties. Photoluminescence (PL), Scanning Electron Microscopy (SEM), UV–visible spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and Raman spectroscopy validate the significance of incorporating various surfactants on ZnO nanoparticles and their photocatalytic efficacy. Indeed, the effect of surfactant types, and mass catalysts on the process performance was investigated. It was observed that ZnO prepared with Sulfobetaine (ZS) exhibits a higher photocatalytic degradation of SMX (94%) after 160 min in the presence of 150 mg of powder of ZnO and [SMX] = 5 mg/l. The pseudo-first-order kinetics rate constants for the photodegradation of SMX were established to be 0.0098 min−1, 0.0078 min−1, 0.010 min−1, and 0.014 min−1 for ZnO prepared respectively by F127, CTAB OTAC and Sulfobetaine.