Mesoporous carbon nanospheres encapsulated CoFe2O4 to enhance peroxymonosulfate activation for achieving efficient sulfamethoxazole degradation

Abstract

To effectively improve the electron transfer ability mediated by carbon nanomaterials and enhance their activation ability towards peroxymonosulfate (PMS), a novel bimetallic/carbon matrix composite (Mesoporous carbon nanospheres encapsulated CoFe₂O₄, CoFe₂O₄@MCHS) was prepared for the activation of PMS to degrade sulfamethoxazole (SMX). The system removed 98.55 % of SMX in 30 min using a lower concentration of catalyst (0.05 g/L) and oxidant (1 mM). The superior catalytic performance of CoFe₂O₄@MCHS was due to the high specific surface area and pore structure, which offered numerous active sites, while the distinctive yolk-shell architecture safeguarded the active center and enhanced catalyst stability. Surface-bound radicals and electron transfer played a dominant role in the SMX degrading process, while the CoFe₂O₄@MCHS/PMS system exhibited enhanced oxidation of electron-rich organic compounds. Moreover, CoFe₂O₄@MCHS/PMS exhibited tolerance to a broad spectrum of initial pH levels and demonstrated significant resistance to prevalent anions and humic acid in water, sustaining an effective degradation across various aqueous environments. Four possible degradation pathways of SMX were proposed. In summary, the CoFe₂O₄@MCHS/PMS system was both extremely effective and environmentally friendly, offering a novel approach to treat antibiotic wastewater.