Carbon-based metal-free electrocatalysts have inspired extensive efforts to explore their applications in many nontrivial electrochemical reactions, such as oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), by virtue of the integrated advantages including low cost, sustainability, longevity, and multifunctionality. Herein, N,P co-doped hollow carbon nanofiber (N,P–HCNF) membranes were facilely prepared via coaxial electrospinning technology, which are bestowed with a hierarchical porous architecture, turbostratic structures, and abundant catalytically active sites such as doping, defects, and edges. Benefiting from structural features of the one-dimensional (1D) carbon hollow nanoarchitecture, which affords plentiful active sites, continuous conducting pathways, and benign mass transfer channels, the resultant catalyst reveals an excellent trifunctional electrocatalytic activity for ORR, OER, and HER. Impressively, it exhibits one of the best metal-free bifunctional electrocatalytic activities in oxygen electrocatalysis as characterized by a low potential deviation (ΔE) of 0.73 V between the half-wave potential (E _1/2) for ORR and the potential reaching 10 mA cm⁻² (E_j=10) for OER. Significantly, further investigations demonstrate that the effect of mass transfer makes a great difference to electrocatalytic activity, mainly through enlarged specific surface area to affect intrinsic catalytic activity and the ionic resistance in pores. This work sheds light on the design, fabrication, and regulation of highly active metal-free electrocatalysts with abundant active sites and tuned pore structures for electrocatalysis and other applications.

碳基无金属电催化剂凭借其综合性，激发了人们广泛的努力来探索其在许多非平凡的电化学反应中的应用，例如氧还原反应（ORR），氧释放反应（OER）和氢释放反应（HER）。优势包括低成本，可持续性，寿命和多功能性。在此，N，P共掺杂中空碳纳米纤维（N，P-HCNF）膜是通过同轴静电纺丝技术轻松制备的，该膜具有分层的多孔结构，涡轮层结构和丰富的催化活性位点，例如掺杂，缺陷和边缘。得益于一维（1D）碳中空纳米结构的结构特征，该结构具有丰富的活性位点，连续的传导途径和良性的传质通道，所得催化剂对ORR，OER和HER具有出色的三官能电催化活性。令人印象深刻的是，它表现出氧电催化中最好的无金属双功能电催化活性之一，其特征在于半波电势（E _1/2）之间的电势偏差（ΔE）为0.73 V ），ORR的电势达到10 mA cm ^-2（E _{j = 10}）。重要的是，进一步的研究表明，传质的影响对电催化活性有很大的影响，主要是通过扩大比表面积来影响固有的催化活性和孔中的离子电阻。这项工作为高活性无金属电催化剂的设计，制造和调节提供了亮点，该催化剂具有丰富的活性位点和可调节的孔结构，可用于电催化和其他应用。