Fe-Cu Co-Doping Enhanced Peroxymonosulfate Activation for the Degradation of Dimethyl Carbonate in Lithium-Ion Battery Recycling Wastewater

The lithium battery recycling industry is developing rapidly, and the rapid oxidation and degradation of dimethyl carbonate (DMC) in the wastewater generated by this industry is of crucial importance. In this study, Fe and Cu dopants were controlled and the C-SiO2framework with porous structures was constructed to synthesize FeCuC-SiO2and C-SiO2catalysts. The former could achieve 91.65% of DMC degradation within 60 min through peroxymonosulfate (PMS) activation, and the degradation rate was increased to 4.44 times compared to C-SiO2without Fe and Cu doping. And under optimized conditions, a DMC degradation rate of 90.57% can be achieved within 10 min by FeCuC-SiO2. The catalyst has good stability and the catalytic activity can be maintained during reuse process for five times with over 70% of DMC degradation rate, 58.9% of mineralization rate, and a relatively low amount of metal leaching. Moreover, the degradation rate can still remain above 70% with the existence of impurity anions, demonstrating a strong salt resistance. Hydroxyl radicals (OH•), sulfate radicals (SO4•−), and1O2were found to dominant the reaction in the FeCuC-SiO2-PMS system, which were involved in both free radical and non-free radical pathways and led to excellent catalytic oxidation performance and environmental adaptability. In general, a novel design for a Fenton-like catalyst was presented, providing a theoretical basis for the improvement of oxidation efficiency and the regulation of reaction pathways in Fenton-like reactions.