Tuning the electronic structure of carbon fibers and Fenton-like oxidation pathways via in situ generation of MnO nanoparticles

This study investigates microenvironment-engineered Mn-CNF catalysts with tailored active sites to boost oxidant utilization in Fenton-like water purification. The catalyst was synthesized by in situ anchoring Mn sites onto the carbon framework, improving the electrical conductivity of the carbon fibers and coordination capacity for peroxydisulfate (PDS). The Mn-CNF/PDS system achieved a high degradation rate of target pollutants via electron transfer process (ETP), with 90.2 % TCH removal after 120 hours in continuous flow operation, while maintaining Mn leaching below 0.1 ppm. Theoretical calculations revealed a stronger adsorption energy for PDS on Mn-CNF (-7.35 eV) compared to MnO (-4.35 eV) and CNF (-4.24 eV), with the lowest Gibbs free energy for complex formation. The rapid ETP demonstrated high selectivity in the presence of competing ions and natural organic matter. This work provides a novel strategy for sustained, efficient water purification through microenvironmental engineering in Fenton-like catalysts.