Unleashing the Power of Cobalt Pyroborate: Superior Performance in Sulfate Radical Advanced Oxidation Processes

Abstract

This study presents a structurally robust, cobalt pyroborate (Co2B2O5) as a heterogeneous for advanced oxidation process (AOP). The Co2B2O5 nanoparticles were systematically characterized and employed to activate peroxymonosulfate (PMS) effectively in the degradation of various organic recalcitrant. When compared to conventional heterogeneous CoO and Co3O4 catalyst in sulfate radical-advanced oxidation process (SR-AOP), the Co2B2O5catalyst exhibited seven-fold and 2.7-fold increases in degradation rate, respectively. The Co2B2O5/PMS system was optimized to enable degradation of a diverse array of persistent organic pollutants, including tetracycline, 4-nitrophenol and sulfamethoxazole, with respective first-order rate constants of 0.136 min-1 and 0.104 min-1, and 0.092 min-1, respectively Mechanistic insights, supported by selective trapping experiments and electron paramagnetic resonance (EPR) analyses revealed surface-bound sulfate radicals serve as the primary reactive oxygen species (ROS) under dark conditions. Singlet oxygen species also contributed to the degradation process via a non-radical pathway. Remarkably, the catalyst maintained its effectiveness in the presence of natural organic matter, highlighting its potential practical applicability for wastewater treatment. This study presents single-component cobalt pyroborate catalyst with a high catalytic activity under varying conditions, thus providing unprecedented benefits for industrial wastewater treatment applications.