Cobalt oxide composite g-C3N4 for visible light-activated PMS degradation of PAHs: The combined effects of free radicals and non-free radicals

Polycyclic aromatic hydrocarbons(PAHs), as a kind of persistent organic pollutant, pose serious threat to humans and organisms’ health. In this work, cobalt oxide/g-C₃N₄ composites with low cobalt content (≤0.5 wt%) were prepared via a high-temperature solid-phase method for visible-light-driven catalytic activation of peroxymonosulfate (PMS), as an efficient system, to degrade PAHs in water. It is noteworthy that this work systematically studied the properties of the prepared materials and the mechanism of active species generation for pollutant degradation. The material forms a p-n heterojunction structure and exhibits visible light absorption. Under conditions where both the catalyst and PMS concentrations are 100 mg/L, near-complete degradation of 0.2 mg/L phenanthrene(PHE) can be achieved within 35 min. Mechanistic studies revealed that the mainly combined contribution of active species are 1 O 2 and O •— 2 , indicating that the degradation process involves both radical and non-radical pathways. After 5 cycles, the material retained 80% degradation efficiency while maintaining structural stability and minimal cobalt leaching, providing a feasible approach for developing stable and efficient heterogeneous photocatalysis-PMS systems. Download: Download high-res image (200KB) Download: Download full-size image