A novel modified Fe–Mn binary oxide graphite felt (FMBO-GF) cathode in a neutral electro-Fenton system for ciprofloxacin degradation

Highlights: • A novel modified graphite felt of FMBO-GF has been prepared to remove ciprofloxacin. • FMBO/AC loaded amount, initial pH and applied current have been optimized. • FMBO-GF cathode can remove CIP in neutral environment in EF system. • Ciprofloxacin/TOC removal efficiency reached 92.89% and 93.77%, respectively. • More active sites, larger surface area and volume pore after cathode modification. A graphite felt (GF) cathode was firstly modified by Fe–Mn binary oxide (FMBO), active carbon (AC), carbon black (CB), and polytetrafluoroethylene (PTFE), which exhibits satisfactory ciprofloxacin (CIP) removal efficiency at neutral pH value in electro-Fenton (EF) system. Morphological data showed that modified cathodes have larger surface area and volume pore as well as more active sites. And electrochemical properties have proved stronger current response after modification. In compassion to the unmodified GF, the FMBO/AC/CB modified GF (FMBO-GF) has wider pH range and higher CIP removal efficiency due to its unique nanoparticles structure. The CIP removal efficiency achieved 95.40% in 30 min, and the removal efficiency of total organic carbon (TOC) achieved 93.77% in 2 h when conditions were optimal (25 mg/L initial CIP concentration, 2 mA/cm² current density, FMBO/AC: CB: PTFE of 1:1:5, and 7 initial pH value) in this study. The results of great degradation and mineralization of CIP in this study indicate that the FMBO-GF cathode has huge potential on antibiotics removals in neutral environment.