Activation of peroxymonosulfate by Cu⁰/CuFeO₂ composite for tetracycline hydrochloride degradation with free radical...

The widespread use of tetracycline has made the efficient and environmentally friendly treatment of tetracycline-contaminated wastewater a pressing issue in environmental management. This study synthesized high-purity and uniformly mixed Cu⁰/CuFeO₂ composite materials using a one-step hydrothermal method, aiming to enhance the catalytic activation of peroxymonosulfate (PMS) through the synergistic effect of zero-valent metal and bimetallic compounds. The Cu⁰/CuFeO₂ composite demonstrated exceptional PMS activation performance, achieving 84% tetracycline hydrochloride (TCH) degradation within 1 min and 91% degradation within 20 min. The degradation process involved the synergistic action of •OH, SO₄ ^•-, ¹O₂, and electron transfer. The degradation intermediates of TCH were identified using high-performance liquid chromatography-mass spectrometry (HPLC-MS), and four potential degradation pathways were proposed. Furthermore, Cu⁰/CuFeO₂ exhibited robust degradation performance across a wide pH range and maintained high efficiency in complex aqueous environments. Even after five cycles, the composite retained 78% of its degradation efficiency, demonstrating excellent stability and reproducibility in the degradation of TCH using the Cu⁰/CuFeO₂/PMS system. PRACTITIONER POINTS: A high-purity and uniformly mixed Cu⁰/CuFeO₂ composite was synthesized. Robust catalytic activity and stability was observed for the synthesized catalyst. Synergistic contributions from •OH, SO₄ ^•-, ¹O₂, and e^- resulted in TCH degradation. Four potential TCH degradation pathways were derived.