Facile synthesis of iron oxide supported on porous nitrogen doped carbon for catalytic oxidation

Highlights: • Porous nitrogen doped carbon supported Fe_xO_y is synthesized by one-pot pyrolysis. • SiO₂ template and NaNO₃ activation are used for large surface area achieving. • The final composites show excellent performance for organic pollutants degradation. • O₂⁻ and ¹O₂ are revealed to be the dominated reactive oxygen species. Iron oxide (Fe_xO_y) supported on porous nitrogen doped carbon is synthesized by a facile pyrolysis method. SiO₂ and NaNO₃ are used as the template and activation agent respectively for porous structure generation and large specific surface area (SSA) creation. The obtained materials show superior catalytic oxidation ability and can activate peroxymonosulfate (PMS) in a wide pH range (3–9) to degrade organic pollutants. The degradation process is a two-stage reaction, including a rapid initial decay and a following slow reaction stage. According to the free radical quenching experiments, electron paramagnetic resonance (EPR) spectroscopy analysis, and electrochemical tests, the superoxide radical (O₂⁻) and singlet oxygen (¹O₂) are proved to play crucial roles in organics degradation. The high SSA (773 m² g⁻¹), abundant of structural defects, and synergistic effect between Fe_xO_y and the nitrogen doped carbon are the key factors for the enhanced activity. The catalysts in this study can be synthesized easily and contain no toxic metals, thus should have great potential in the wastewater remediation.