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

In this study, the NiCo4-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 cipro-floxacin (CIP) degradation. The OV-rich NiCo4-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 %. SO4 center dot- , (OH)-O-center dot, O-2(center dot-) and O-1(2) were involved in the degradation of CIP, with O-2(center dot-) contributing the most, followed by SO4 center dot-, (OH)-O-center dot and O-1(2). Ethanol, as solvent, could modulate the intrinsic electron properties and produce abundant OVs on the surface of NiCo4-LDH, which enhanced the generation of O-2(center dot-) . This study shed new light on the skillful design and application of heterogeneous catalysts for environmental remediation.

Automated summary

In this study, NiCo4-LDH with abundant surface oxygen vacancies (SOVs) was synthesized and used as a heterogeneous catalyst for ciprofloxacin (CIP) degradation via the activation of peroxymonosulfate (PMS). The NiCo4-LDH/PMS system with oxygen vacancies showed excellent CIP removal efficiency and rapid kinetics, with 95.0% of CIP degraded within 10 minutes and a COD removal rate of 71.2%. Various reactive species, including SO4•-, (OH)•, O2•-, and O1(2), were involved in the degradation process, with O2•- contributing the most.