Direct electron transfer double-defect core–shell LaVCuOδ@CeOx nanoreactors boosting hydrogen peroxide activation for enhanced quinoline removal

Abstract

Double oxygen vacancies (VO) tuned core–shell LaVCuOδ@CeOx (VO-LCO@CeOx) nanoreactors with direct electron transfer (DET) structure was synthesized as an effective heterogeneous Fenton-like catalyst for the quinoline removal. The DET structure was constructed by electron-rich ≡Cu center of VO-LCO core and electron-capture center of CeOx shell for electrons supplying and consuming. This structure elevated total VO levels of catalyst through the removal of oxygen atoms in CeO2 from attice to interface sites. Meanwhile, the ≡Ce(III) acted as reactive sites for the adsorption of hydrogen peroxide (H2O2) to form surface peroxide species, and then the electron-rich ≡Cu center was further provided electrons to surface peroxide species by DET to produce hydroxyl radical. Moreover, the newly formed surface VO would also be further promote hydroxyl radical production through self-activation of H2O2. This catalyst displayed excellent catalytic activity and stability. The density functional theory (DFT) results further pointed out that this structure had excellent adsorption energy, and generable electron transfer from VO-LCO to CeOx. This work provided a novel approach for the development of heterogeneous Fenton-like catalysts to degrade quinoline wastewater.