The fabrication of cost effective and efficient electrocatalysts with functional building blocks to replace noble metal ones is of great importance for energy related applications yet remains a great challenge. Herein, we report the fabrication of a hierarchical structure containing CNTs/graphene/transition-metal hybrids (h-NCNTs/Gr/TM) with excellent bifunctional oxygen electrocatalytic activity. The synthesis was rationally designed by the growth of shorter nitrogen-doped CNTs (S-NCNTs) on longer NCNTs arrays (L-NCNTs), while graphene layers were in situ generated at their interconnecting sites. The hybrid material shows excellent OER and ORR performance, and was also demonstrated to be a highly active bifunctional catalyst for Zn–air batteries, which could be due to rapid electron transport and full exposure of active sites in the hierarchical structure.

中文翻译：

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具有互连分层结构的对齐 N 掺杂碳纳米管束作为高效的双功能氧电催化剂†

制造具有成本效益和高效的具有功能构件的电催化剂来替代贵金属对于能源相关应用非常重要，但仍然是一个巨大的挑战。在此，我们报告了具有优异双功能氧电催化活性的包含 CNTs/石墨烯/过渡金属杂化物 (h-NCNTs/Gr/TM) 的分层结构的制造。该合成是通过在较长的 NCNT 阵列 (L-NCNT) 上生长较短的氮掺杂 CNT (S-NCNT) 来合理设计的，而石墨烯层是原位的在它们的互连站点生成。这种混合材料显示出优异的 OER 和 ORR 性能，并且还被证明是一种用于锌空气电池的高活性双功能催化剂，这可能是由于快速电子传输和分层结构中活性位点的充分暴露。