Engineering a High-Performance Co/MPC Catalyst via Microwave- Assisted Pyrolysis for Rapid Atrazine Elimination through PMS Activation

This study presents a high-performance cobalt catalyst supported on microwave-pyrolyzed biochar (Co/MPC) for efficient peroxymonosulfate (PMS) activation to degrade atrazine (ATZ). The microwave-assisted pyrolysis (MWP) technique yielded biochar (MPC) with superior textural properties—specifically, a significantly higher specific surface area (214.18 m²/g) and pore volume (0.46 cm³/g)—compared to conventionally pyrolyzed biochar (BC). This enhanced porous structure facilitated the uniform dispersion of ~ 5 nm cobalt nanoparticles, resulting in the highly active Co/MPC catalyst. The Co/MPC + PMS system achieved over 99% ATZ degradation within just 5 minutes, outperforming its conventionally prepared counterpart (Co/BC). The catalyst demonstrated robust performance across a range of PMS dosages and pollutant concentrations, and exhibited strong tolerance to common coexisting anions. Radical quenching experiments and electron paramagnetic resonance (EPR) analysis identified hydroxyl radicals (•OH) and sulfate radicals (SO₄•⁻) as the dominant reactive species responsible for the rapid degradation. This work highlights the significant advantage of microwave-assisted synthesis in creating advanced carbon-metal catalysts and offers a highly efficient, stable, and practical solution for the remediation of persistent organic pollutants like ATZ without requiring additional energy input.