Cobalt MOF-derived Co/CoO/C composites for efficient peroxymonosulfate activation and oxytetracycline degradation

Abstract

A new cobalt MOF (JLNU-15, JLNU = Jilin Normal University) was synthesized and used as a precursor to produce carbon material Co/CoO/C-800 by pyrolysis at 800 °C. The Co/CoO/C-800 was characterized by SEM, TEM and XPS. This study employed a Co/CoO/C-800 composite material as a catalytic agent to initiate PMS for OTC removal. Under optimized conditions with 0.12 g L⁻¹ of the catalyst and 0.24 g L⁻¹ of PMS, over 97% of OTC was effectively decomposed from an aqueous solution containing 25 mg L⁻¹ of the initial antibiotic concentration. Degradation efficiency was assessed under varying conditions of PMS concentration, catalyst amount, solution acidity and alkalinity, and background ions. The quenching experiments demonstrated that the degradation process proceeded through dual mechanisms: radical-based reactions (SO₄˙⁻ and OH˙) combined with non-radical pathways (¹O₂). The cyclic experiments showed that the catalytic effect of Co/CoO/C-800 was still about 90% after 4 times of use. This study provides a novel cobalt/porous-carbon material by using Co-MOF as precursor.