Regulating Radical–Nonradical Pathways via Phosphorus-Engineered Cobalt Nanocatalysts for Fenton-Like Oxidation

The simultaneous presence of radical and nonradical reaction pathways in advanced oxidation processes complicates the precise control over efficiency and selectivity, which are important for addressing various degradation needs. Here, the phosphated cobalt-based nanocomposites (CoP@NC) were synthesized for activating peroxymonosulfate (PMS) to switch between radical and nonradical pathways through the formed P defects in a Fenton-like system. The phosphorization on CoNC was confirmed to effectively enhance the electronic transfer efficiency and lower the reaction activation barrier, further boosting the PMS activation efficiency. Meanwhile, the abundance of defective electrons increased the amounts of singlet oxygen on the catalyst surface, boosting organic pollutant decomposition with a normalized k-value of up to 1515 min-1 M-1, significantly higher than previously reported studies. The system showed exceptional pollutant degradation, especially for electron-rich contaminants like methyl orange and tetracycline, along with high PMS utilization, minimal interference from complex water matrices, and broad adaptability to varying pH and water quality conditions. Life cycle assessment and long-term operational stability at the system level demonstrate the promising potential for industrial-scale wastewater treatment. This study provides important insights for guiding the design of Fenton-like catalysts, aiming toward sustainable and low-carbon-water purification solutions.