Oxygen-Vacancy-Engineered Co-Doped CeO 2 Nanosheets for Dual-Pathway Activation of Peroxymonosulfate

Developing catalysts with superior electron transfer capabilities has emerged as a key challenge in the activation of peroxymonosulfate (PMS). Herein, the morphology and electronic structure of CeO2 catalysts were modulated through Co doping, thereby generating a higher concentration of oxygen vacancies (Ovs) and providing additional active sites for PMS activation. At a Co doping level of 25%, the two-dimensional (2D) nanosheet-structured CeO2 achieved 93.6% degradation of Tetracycline hydrochloride (TC) within 60 min, with a rate constant (k) of 0.042 min–1. Quenching experiments and electron spin resonance (ESR) analyses elucidated the involvement of both radical and nonradical pathways in the TC degradation process. Density functional theory (DFT) calculations demonstrated that Co-doped CeO2 with Ovs not only reduced the energy barrier for PMS activation but also enhanced the generation of reactive radicals. This study offers novel insights and technical support for the treatment of wastewater contaminated with recalcitrant organic pollutants.