Insufficient catalytic activity and self-restacking of 2D MXenes during catalytic processes would lead to a limited number of active sites, sluggish ionic kinetics and poor durability, extremely restricting their application in Zn–air batteries (ZABs). Herein, a facile and moderate synthetic path is reported for the synthesis of a 3D porous framework, Nb₂C MXene/reduced graphene oxide aerogel coupled with NiFe alloy nanoparticles (NiFe/MG) as a cathode in wearable ZABs. The large specific surface area, abundant functional groups (O, –OH, and –F), porosity and rich channels of 3D NiFe/MG aerogel are beneficial for increasing the number of active sites, facilitating the diffusion of electrolyte and promoting transference of electrons. As a result, the NiFe/MG electrocatalyst achieves outstanding bifunctional activity delivering an indicator ΔE of 0.79 V, which is superior to the state-of-the-art commercial Pt/C + IrO₂ benchmark (ΔE = 0.84 V). Specifically, the as-assembled wearable ZAB exhibits a remarkable peak power density (96.1 mW cm⁻²), long-term durability and outstanding mechanical stability. This study provides an ingenious strategy to promote the application of 3D MXene-based bifunctional electrocatalysts for metal–air batteries.

中文翻译：

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3D 多孔 Nb2C MXene/还原氧化石墨烯气凝胶结合 NiFe 合金纳米颗粒用于可穿戴锌空气电池

2D MXenes在催化过程中催化活性不足和自重堆积会导致活性位点数量有限、离子动力学缓慢和耐久性差，极大地限制了它们在锌空气电池（ZABs）中的应用。在此，报道了一种用于合成 3D 多孔骨架 Nb ₂的简便且适度的合成路径C MXene/还原氧化石墨烯气凝胶与 NiFe 合金纳米粒子 (NiFe/MG) 结合作为可穿戴 ZAB 的阴极。3D NiFe/MG气凝胶的大比表面积、丰富的官能团（O、-OH和-F）、孔隙率和丰富的通道有利于增加活性位点的数量，促进电解质的扩散和电子的转移. 因此，NiFe/MG 电催化剂实现了出色的双功能活性，指标 Δ E为 0.79 V，优于最先进的商业 Pt/C + IrO ₂基准（Δ E = 0.84 V）。具体来说，组装好的可穿戴 ZAB 表现出显着的峰值功率密度 (96.1 mW cm ^-2)、长期耐用性和出色的机械稳定性。该研究为促进基于 3D MXene 的双功能电催化剂在金属-空气电池中的应用提供了一种巧妙的策略。