The residual ciprofloxacin (CIP) in water seriously menaces the ecological safety and public health. Here, a Fe-free photo-electro-Fenton-like (PEF) system was designed for efficient degradation of CIP in water. A Z-scheme MnOx/g-C3N4 (MCN) nanocomposite with low-cost, large specific surface area and abundant active sites was successfully synthesized as a photoelectric catalyst. The XPS analysis indicated the presence of Mn2+, Mn3+ and Mn4+ in the MCN (1:6) composite, and the conversion among polyvalent manganese made the decomposition of H2O2 more efficient. Therefore, the manganese ions replaced the Fe element in traditional Fenton system. With the MCN (1:6), the PEF system could also produce O2-, OH and h+ under the visible light irradiation. The synergetic excitation of multiple active species promoted the rapid decomposition of CIP. Besides, the polyvalent property of manganese oxide resulted in the presence of oxygen vacancies which could improve the electrocatalytic reactivity of the catalyst. Finally, the degradation efficiency of CIP was 96.23% in 120 min and the mineralization efficiency was 80.02% in 240 min.
Keywords: Ciprofloxacin; MnO(x)/g-C(3)N(4); Photo-electro-Fenton-like; Polyvalent manganese; Z-scheme heterojunction.
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