Fish scale residues-derived magnetic porous carbon with multiple catalytic platforms for efficient Fenton-like oxidation

Peroxymonosulfate (PMS)-based Fenton-like oxidation has gained attention as a promising technology for wastewater remediation. However, its widespread application is constrained by the lack of high-performance and durable activators. In this study, a magnetic graphite-like porous carbon (MGPC) derived from fish scale residues was synthesized and demonstrated exceptional PMS activation performance, effectively degrading various persistent contaminants with minimal iron leaching (<0.8 mg L⁻ 1 ). Notably, MGPC achieved high degradation rates for sulfamethoxazole (0.13 min⁻ 1  g⁻ 1  L), methylene blue (0.65 min⁻ 1  g⁻ 1  L), tetracycline (0.19 min⁻ 1  g⁻ 1  L), and rhodamine B (1.07 min⁻ 1  g⁻ 1  L), outperforming many state-of-the-art activators. This enhanced activity is attributed to the synergistic effects of multiple active components, including Fe 3 C, Fe 3 O 4 , and a nitrogen-doped carbon matrix. Additionally, the MGPC/PMS system exhibited strong resistance to interference from background constituents and maintained broad pH adaptability (3–9). Impressively, over 95 % of methylene blue was degraded after five consecutive cycles. The MGPC powders were easily recovered using an external magnetic field, eliminating the need for complex separation processes. Radical quenching experiments, in-situ electron paramagnetic resonance (EPR) analysis, and chronoamperometry confirmed that the MGPC/PMS system operates through two non-radical pathways: 1 O 2 -mediated oxidation and direct electron transfer. This innovative approach to designing efficient PMS activators from environmental waste offers a sustainable strategy for environmental pollution control.