Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles for bisphenol A degradation

Abstract

Herein, Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method. The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bisphenol A removal. Based on the results of X-ray diffraction, scanning electron microscopy, and energy dispersion spectroscopy, Cu–Al bimetallic oxide was determined as CuO-Al₂O₃, and mesoporous silica spheres were found around the these particles. At 30 min, a bisphenol A degradation level of 90% was achieved, and it remained at over 60% after five consecutive cycles, indicating the catalyst’s superior capacity and stability. In terms of removal performance, the radical pathway (including {\text{SO}}_{\text{4}}^{\text{•‒}}, OH •, and {\text{O}}_{\text{2}}^{\text{•‒}}) and singlet oxygen ({}^{\text{1}}{\text{O}}_{\text{2}}) played minor roles, while electron migration between bisphenol A, potassium peroxydisulfate, and the catalyst played a dominant role. The introduction of Al₂O₃ promoted the formation of surface oxygen vacancies, which improved ligand complex formation between potassium peroxydisulfate and the catalyst, thereby facilitating electron migration. Furthermore, mesoporous silica spheres augment not only enhanced bisphenol A adsorption but also alleviated Cu leaching. Overall, this work is expected to provide significant support for the rational development of catalysts with high catalytic activity for persulfate activation via surface electron migration.

Graphical abstract

Keywords

Cu–Al bimetallic oxides / mesoporous silica spheres / peroxydisulfate / bisphenol A

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Higher Education Press