MOF/PAN-derived copper nanoparticles supported carbon nanorods (Cu@CNRs) for H₂O₂, S₂O₈²⁻ and HSO₅⁻ activated degradation of sulfamethoxazole

Metal–organic frameworks (MOFs) have currently attracted interest as effective self-sacrificial templates for the fabrication of hierarchical porous metal–nanoparticle materials. This study involved the synthesis of Cu-based MOF-loaded polyacrylonitrile (MOF/PAN) fibers using electrospinning, subsequently subjected to calcination in a nitrogen environment to yield Cu nanoparticle-loaded carbon nanorods (Cu@CNRs) as heterogeneous catalysts. The catalytic performance of prepared Cu@CNRs was investigated via hydrogen peroxide (H₂O₂), peroxydisulfate (S₂O₈²⁻), and peroxymonosulfate (HSO₅⁻) activated degradation of sulfamethoxazole (SMX). The activation performance of Cu@CNRs followed the sequence: HSO₅⁻ > S₂O₈²⁻ > H₂O₂, indicating that HSO₅⁻ was the most effective oxidant under identical conditions. The Cu@CNR-I/HSO₅⁻ system demonstrated exceptional efficacy, attaining 99.99 % SMX removal in 30 min and a significant rate constant of 0.2312 min⁻¹. The improved activity is due to the hierarchical porous structure, elevated surface area, plentiful active sites, and robust Cu-N-C/HSO₅⁻ synergy. The carbonization created a polarization disparity in CuN coordination, thereby promoting PMS activation by Cu(I/II) species. Radical quenching and EPR tests revealed that SO₄^•- and OH^• radicals predominated the degradation route. The primary operating factors, such as catalyst and oxidant dose, solution pH, SMX concentration, coexisting anions, and humic acid, were carefully examined. The catalyst Cu@CNR-I exhibited remarkable catalytic stability and reusability over five cycles, indicating significant potential as a sustainable heterogeneous catalyst for wastewater treatment applications.