Modulating intrinsic activity and coupling with transition metal phosphides are encouraging strategies to enhance the electrochemical performance of carbon-based materials. In this study, N-doped carbon nanotubes were derived from polyaniline nanotubes by the guided growth of the soft template micelles comprising Fe³⁺ ions and methyl orange. Phytic acid was employed to detain Fe³⁺ ions from washing away so as to form iron phosphide (FeP and Fe₂P) nanoparticles. NH₃ plasma etching was further exerted for concurrent phase engineering of iron phosphide nanoparticles by transforming Fe₂P to FeP, creating intrinsic carbon defects, as well as regulating the specific surface area and pore structure of the N-doped carbon nanotubes. It demonstrated that the phase transformation from Fe₂P to FeP with higher crystallinity, together with the generated intrinsic carbon defects, played significant roles in promoting the oxygen reduction reaction (ORR) performance of the porous N-doped carbon nanotubes. As expected, the optimized composite (denoted as CV-FeP/NPCNT-30) revealed brilliant electrocatalytic ORR performance in 0.1 mol L⁻¹ KOH aqueous solution, holding a more positive half-wave potential of 920 mV (vs. Reversible Hydrogen Electrode), a high diffusion limiting current density of 5.89 mA cm⁻², delightful stability and methanol tolerance. Consequently, the liquid Zn–air battery (ZAB) established with CV-FeP/NPCNT-30 as the electrocatalyst in air-cathode manifested an outstanding power density (221 mW cm⁻²) and specific capacity (851.5 mA h g⁻¹_Zn), outperforming the liquid ZABs based on the commercial Pt/C and some relevant electrocatalysts recently reported.

中文翻译：

---

NH3 等离子体蚀刻衍生的多孔氮掺杂碳纳米管，具有 FeP 纳米颗粒和固有碳缺陷，可促进可充电锌空气电池中的氧还原

调节本征活性和与过渡金属磷化物的偶联是增强碳基材料电化学性能的令人鼓舞的策略。在本研究中，通过包含Fe ³⁺离子和甲基橙的软模板胶束的引导生长，从聚苯胺纳米管衍生出N掺杂碳纳米管。使用植酸来阻止Fe ³⁺离子被冲走，从而形成磷化铁（FeP和Fe ₂ P）纳米颗粒。通过将Fe ₂ P转化为FeP、产生内在碳缺陷以及调节N掺杂碳纳米管的比表面积和孔结构，NH ₃等离子体蚀刻进一步应用于磷化铁纳米粒子的并发相工程。结果表明，从Fe ₂ P到结晶度较高的FeP的相变以及产生的本征碳缺陷对促进多孔氮掺杂碳纳米管的氧还原反应（ORR）性能发挥了重要作用。正如预期的那样，优化的复合材料（表示为 CV-FeP/NPCNT-30）在 0.1 mol L ^-1 KOH 水溶液中表现出出色的电催化 ORR 性能，保持更正的半波电位 920 mV（与可逆氢电极相比） ，5.89 mA cm ^-2的高扩散极限电流密度，良好的稳定性和甲醇耐受性。因此，以CV-FeP/NPCNT-30作为空气阴极电催化剂建立的液体锌空气电池（ZAB）表现出出色的功率密度（221 mW cm ^-2）和比容量（851.5 mA hg ^-1 _Zn） ，优于基于商用 Pt/C 和最近报道的一些相关电催化剂的液体 ZAB。