Bimetallic MOFs-derived CuS/FeMn-C composite materials efficiently activate persulfate for catalytic degradation of ciprofloxacin

Background

Ciprofloxacin (CIP), a common fluoroquinolone, is often found in wastewater, endangering the environment and human health. Given the limited efficacy of traditional physical/biological methods in degrading ciprofloxacin, it is imperative to devise economically viable new materials and methods for its degradation.

Methods

Magnetic CuS/FeMn-C composites were synthesized using solvothermal and pyrolytic methods to activate peroxymonosulfate (PMS) for CIP degradation, and its properties were investigated through a series of characterizations. The effects of factors such as catalyst concentration, PMS concentration, initial CIP concentration, initial pH value and coexisting inorganic anions on catalytic degradation were studied, and the degradation mechanism was explored.

Significant findings

The results indicated that, under optimal circumstances, 95.43 % CIP degradation was achieved within 20 min, with a reaction rate constant of 0.1053 min⁻¹. Radical quenching and electron paramagnetic resonance (EPR) results showed that $S{O_4}^{•-}$ and ¹O₂ were key species in CIP degradation. The enhancement of catalytic activity is attributed to the synergistic effects of metal ions. Redox cycles between Fe³⁺/Fe²⁺, Mn³⁺/Mn²⁺ and Cu⁺/Cu²⁺ took place at the CuS/FeMn-C interface. Additionally, the magnetic CuS/FeMn-C composite material has exceptional stability and recyclability, positioning it as a potential option for the remediation of refractory contaminants in applications in the environment.