Electronic Structure Modulation in N, P, S Tri‐Doped Nanofibers with Interpenetrated Pores for Enhanced Oxygen Reduction Reaction

Abstract Multi‐heteroatom‐doped metal‐free carbons with well‐tailored electronic structures are regarded as promising oxygen reduction reaction (ORR) catalysts. However, their active sites are often hindered by the carbon matrix, resulting in reduced catalytic activity. Herein, nitrogen, phosphorus, and sulfur tri‐doped hollow hierarchical porous carbon nanofibers (NPS‐HPCNFs) with interpenetrated pores are synthesized using a facile coaxial electrospinning method. The distinctive steric confinement induced by the interpenetrated pores created a positive microenvironment for the ORR. As a result, the resultant NPS‐HPCNF catalyst exhibits a half‐wave potential (E_1/2) of 0.86 V (vs. RHE) and superb long‐term stability in 0.1 m KOH. Furthermore, the zinc‐air battery (ZAB) assembled with NPS‐HPCNF achieves a great peak power density of 210 mW cm⁻² and a superior specific capacity of 795 mAh g⁻¹, outperforming the commercial Pt/C candidate. In addition, density functional theory (DFT) calculations reveal that the synergistic effect of the N, P, S tri‐doping combined with defect sites effectively regulated the electronic structure and significantly enhanced the ^*OOH adsorption, thus accelerating the ORR process. Therefore, the tri‐doped carbon nanofibers with abundant interpenetrated pores represent a promising and eco‐friendly alternative to state‐of‐the‐art Pt/C electrocatalysts for various electrochemical energy applications.