Selective oxidation of emerging contaminants by high-valent cobalt(IV)-Oxo species: Constructing high-spin Co(III) sites in Fenton-like system

In this study, a novel strategy for selectively generating Co(IV)=O species during peroxymonosulfate (PMS) activation was proposed, utilizing an optimized Co 4 Cu 1 -layered double hydroxide (LDH) material with low-coordination and high-spin-state Co sites. The incorporation of Cu(II), influenced by the Jahn-Teller effect, altered the geometry and coordination at Co(III) sites, optimizing the filling of Co 3d orbitals. The Co 4 Cu 1 -LDH/PMS system demonstrated exceptional catalytic activity for degrading emerging contaminants (ECs) across various water matrices, with a high concentration of Co(IV)=O generation. Continuous flow experiments showed an average 97.51 % degradation over 10 hours, indicating significant practical potential. Mechanistically, enhanced performance was attributed to a single electron transfer process and optimized orbital configurations for oxygen ligands at Co(III) sites. This study offers both theoretical insights and practical guidance for developing efficient catalysts targeting Co(IV)=O species in Fenton-like systems.