Effects of Ce doping on the Fenton-like reactivity of Cu-based catalyst to the fluconazole

Abstract

In order to fully exploit the potential of Cu-based Fenton systems, Ce was utilized to modify the Cu-based catalysts through one-pot synthesis. A typical antifungal drug, fluconazole (FLC), was selected as the target pollutant to evaluate the reactivity of as-synthetic Cu-Ce bimetallic catalysts. Evaluation test results indicated Ce5%CuOy bimetallic materials exhibit the most excellent catalytic activity. Compared to copper monometallic catalyst, its fluconazole degradation efficiency and TOC removal rate are increased by 20% and 15%, respectively. Ce5%CuOy also possess wide pH applicability (3.0–9.0) and maintain high activity after 4 runs. Radical quenching experiments and fluorescent probes tests showed that hydroxyl radicals (OH) played a dominant role in the degradation of FLC. The various characterization illustrated that Ce doping (2.5–5 at%) significantly improved the properties related to catalytic activity, such as morphology Cu(I) ratio, specific surface area, interface electron transfer rate and unpaired electron content. In particular, the increase in the unpaired electron content and Cu(I) ratio endow more electron-rich centers and active sites on the composite surface, which facilitates the H2O2 to receive electrons and decompose into OH. Finally, the degradation intermediates during fluconazole oxidation were identified by LC/MC.