Electrocatalytic reduction of nitrate by copper/iron oxides supported on nitrogen doped carbon spheres

In recent years, electrocatalytic reduction has gained attention as a promising method for environmentally friendly nitrate treatment. The key to this approach is finding cathode materials with high activity, N2 selectivity, and stability. Researchers are therefore focused on creating efficient catalysts. In this study, nitrogen-doped carbon spheres (NMCS) loaded with Cu and Fe3O4 were synthesized from non-precious metals Fe and Cu and tested for nitrate reduction in water. The bimetal combination effectively reduces the formation of toxic NO2− intermediates and improves material impedance, accelerating electron transfer during the reaction. The mesoporous structure with high surface area also supports metal nanoparticle loading and reduces metal leaching during the process. The resulting Cu/Fe-NMCS-1–3 catalysts showed excellent NO3− reduction (97.04%) and 100% N2 selectivity using electrochlorination. After four cycles, no decline in electrocatalytic performance was observed, suggesting good stability and potential for electrocatalytic nitrate removal.