CuO-multimetal ferrites for synergically boosting peroxydisulfate activation and decontamination by adsorption and oxidation mechanisms

Abstract

The quest for effective nano-multimetal catalysts for environmental remediation and treatment strategies has been a significant topic of interest among scientists. This study focused on boosting CuO catalytic activity by its coupling with multi-metal-spinel ferrite (MMF, Cu_0.5Mg_0.5Fe₂O₄), as a novel recoverable catalyst to degrade ciprofloxacin (CIP) antibiotic under a peroxydisulfate (PDS) activation system. The characterization tests revealed the successful fabrication of the MMF/CuO (MMFC) composite with high purity and excellent crystallinity. The prepared catalyst shows a synergistic effect of adsorption and reactive species-dominated catalytic degradation in the PDS activation system. The MMFC/PDS hybrid system attained a superior performance toward complete CIP (10 mg L⁻¹) degradation (pH: 7.0, MMFC: 0.1 g L⁻¹, and PDS: 2.0 mM) within 20 min reaction with a significant reaction rate constant of 0.355 min⁻¹. The comparative tests confirm a remarkable synergistic effect between MMFC components and PDS to degrade CIP. The crucial contribution of radical and non-radical species to degrade CIP in the MMFC/PDS process was verified by scavenging tests. The MMFC elucidates remarkable reusability and stability during the recycling tests with minimum leaching of metal ions and without changes in structural properties. The MMFC/PDS performance for purifying actual samples was remarkable, implying the high practical applicability of the process. Moreover, the produced intermediates were identified for the design of a plausible degradation pathway of CIP. Overall, this work not only significantly reduces the required chemicals (catalyst and oxidant) but also offers an effective strategy for boosting catalytic activity and the potential environmental applicability of CuO toward efficient degradation of refractory pollutants over PDS-based AOPs.