Cobalt-Silicon Coordination-Induced Nonradical Activation of Peroxymonosulfate for Enhancing the Degradation of Organic Pollutants in Real Wastewater

Nonradical-driven degradation pathways have emerged as a promising solution for the removal of emerging organic pollutants in complex water matrices. How to construct nonradical systems remains a challenge. In this study, a novel silicon carbide (SiC)-supported cobalt single-atom catalyst (Co/SiC) is developed to induce nonradicals activation of peroxymonosulfate toward the degradation of sulfamethoxazole (SMX). The normalized degradation rate of SMX reaches 16.425 L·min⁻¹·g⁻¹·mm⁻¹, significantly outperforming most reported single-atom catalysts. Surface-bound reactive species dominate the SMX degradation process, followed by high-valent cobalt oxo. Experimental and characterization results demonstrate that the unique Co-Si coordination structure facilitated electron transfer, and lowered the energy barrier for the formation of surface-bound reactive species, thereby exhibiting superior resistance to inorganic ions. In a seven-day continuous column experiment, SMX, atrazine, and bisphenol A are completely removed from actual secondary effluent, confirming the stability and effectiveness of the catalyst in real wastewater systems. Moreover, the acute toxicity of treated secondary effluent almost disappears. These results highlight the potential of Co-Si coordination in driving electron transfer for the generation of nonradicals, offering a promising approach to addressing the challenges of the removal of emerging organic pollutants from the complex wastewater.