Efficient Activation of PMS by EDTA-CeCoO3 Composite: Effect of Ce/Co Doping Ratio, Structural Property and Degradation Mechanism

Abstract

The perovskite CeCoO₃ composites were synthesized through the sol–gel method with two complexing agents (citric acid and EDTA) with different Ce/Co molar rations and further applied for peroxymonosulfate (PMS) activation. The physicochemical properties and morphology of CeCoO₃ were characterized using BET, XRD, FT-IR, SEM, TEM, and XPS techniques. When the CeCoO₃ prepared with EDTA as the complexing agent at 600°C and Ce/Co ratio of 1:1, the EDTA-CeCoO₃ exhibited superior physicochemical properties, including a high specific surface area (7.69 m²/g) and pore volume, abundant oxygen vacancies, and optimal exposure of active sites, which is most conducive to activating PMS. The effects of catalyst dosage, PMS dosage, initial pH, natural organic matter, and common anions on CeCoO₃/PMS system for bisphenol A (BPA) degradation were systematically evaluated. The results revealed that CeCoO₃ prepared with EDTA at 600°C Demonstrated excellent catalytic activity for PMS Degradation of BPA, achieving over 97% Degradation efficiency of BPA within 15 min, with a pseudo-first-order reaction rate constant (k) of 0.2909 min⁻¹. Furthermore, CeCoO₃ showed outstanding stability in multiple cyclic experiments. Furthermore, radical quenching experiments confirmed that SO₄^•−, ^•OH, and O₂^•− were the dominant active radicals in the CeCoO₃/PMS system for BPA degradation, and a plausible reaction mechanism was proposed. This study provides new insights into the development of PMS activating catalysts, specifically low-cobalt-content yet highly efficient cobalt-based catalysts.