Constructing Fe3N/MnO heterojunction via heteroatom doping for degrading dye wastewater by heterogeneous electro-fenton system.

Electro-Fenton (EF) has been recognized as a viable and promising strategy for dye degradation. However, EF cathode materials with both high oxygen reduction reaction (ORR) activity and H2O2 selectivity remains a long-term research objective. Herein, a N-MnFe-5 %H2 catalyst was synthesized by hydrothermal method combined with H2 high-temperature calcination reduction method. The N-MnFe-5 %H2 catalyst was excellent electrocatalytic performance, stability and applicability, which achieved a high degradation rate (100 %) within 90 min under acidic conditions of pH 3 for Rhodamine B (Rh B). Combined with XPS and TEM analyses, Fe3N and MnO heterostructures existed within individual nanoparticles of N-MnFe-5 %H2. The synergistic interaction between electron-rich Fe₃N and electron-deficient MnO on Fe3N/MnO heterojunction interface enhanced both 2e⁻ ORR activity, selectivity and H2O2 activated, enabling efficient degradation of diverse dye pollutants. This study provides a novel heterostructure interface modification approach for designing modified transition metal-based cathode materials for high-efficiency dye wastewater treatment by EF.