Joule heating-assisted tailoring Co-MOC derived chainmail catalyst to regulate peroxymonosulfate activation for tetracycline destruction: Singlet oxygen integrated direct electron transfer pathways

Abstract

Rational design of stable and high-efficiency non-precious catalysts to activate peroxymonosulfate (PMS) is crucially important for recalcitrant pollutant elimination. In this study, we present a microwave-assisted combustion heat method to fabricate stable Co-MOC-800 as a highly efficient peroxymonosulfate (PMS) activator for tetracycline hydrochloride (TCH) degradation. Joule heating from short-time microwave irradiation enables the expeditious fabrication of Co-based metal–organic-complex (Co-MOC) precursor, which is carbonized to form the representative Co-MOC-800 chainmail catalyst with a maximum degradation rate of 97% in 10 min. This catalyst still possesses an excellent stability with highly remained activity of the initial cycle after five consecutive runs. The N-doped amorphous carbon encapsulated Co nanoparticles integrated Co-Nx sites play an essential role in activating PMS for TCH degradation through non-radial dominant pathways including singlet oxygen and direct electron transfer. Attributing to the non-radical pathways, the Co-MOC-800-catalyzed PMS activation exhibits relatively high anti-interference ability under different solution pH, inorganic anions and humic acid. Three reaction pathways for TCH degradation are proposed by recording the degradation intermediates, and the toxicity of the detected intermediates was evaluated. The present work provides a vivid example for simply fabricating efficient Co-based catalysts for recalcitrant pollutant elimination via activating PMS.