Efficient degradation of ciprofloxacin by activated peroxymonosulfate using OV-rich NiCo4-LDH: Insights into radical production pathway and catalytic mechanism

In this study, the NiCo 4 -LDH with abundant surface oxygen vacancies (SOVs) was synthesized by a simple solvent thermal method, and was used to activate peroxymonosulfate (PMS) through heterogenous catalysis for ciprofloxacin (CIP) degradation. The OV-rich NiCo 4 -LDH/PMS system exhibited excellent CIP removal efficiency and rapid kinetics, as 95.0 % of the CIP was degraded within 10 min and the COD removal rate was 71.2 %. SO 4 •− , • OH, O 2 •− and 1 O 2 were involved in the degradation of CIP, with O 2 •− contributing the most, followed by SO 4 •− , • OH and 1 O 2 . Ethanol, as solvent, could modulate the intrinsic electron properties and produce abundant OVs on the surface of NiCo 4 -LDH, which enhanced the generation of O 2 •− . This study shed new light on the skillful design and application of heterogeneous catalysts for environmental remediation.