Carbon-framework-encapsulated CoMn2O4 spinel derived from electrospun nanofiber coupling via the photothermal approach reinforces PMS activation to eliminate 2,4-dichlorophenol

Abstract

Although metal–carbon combinations have been demonstrated to promote efficiency in the advanced oxidation process (AOP), multidimensional coupling by exploiting metal–carbon interactions, dual-metal redox cycles, and photothermal synergetic catalysis remains rare in AOP. Here, we report carbon framework hybridized plasmonic CoMn₂O₄ spinel composite catalysts derived from electrospun nanofibers by tuning thermal processing. The multiple active species of Co(II/III) and Mn(II/III/IV) were coupled into the spinel structure of the CoMn₂O₄ nanoparticles, affording fast electron transfer and abundant redox pairs of active species. The constructed abundant M–O–C interactions and more active Co(II) and Mn(III) species in the optimal CMO-C-600 are responsible for the promotive activation of PMS to generate the more singlet oxygen (¹O₂) and sulfate radical (SO₄˙⁻). Thereby, the resulting optimal catalysts showed excellent catalytic efficiency for 2,4-dichlorophenol degradation, and the reaction rate constant (0.881 min⁻¹) was ∼4 times higher than that (0.218 min⁻¹) of CoMn₂O₄ alone. In addition, we further revealed the appreciable photothermal effect of plasmonic CoMn₂O₄ spinel coupling with carbon composites irradiated by sunlight, which accelerates the highly concentrated 2,4-dichlorophenol (50 ppm) degradation within 7 min under the generated localized surface heating function.