Abstract In recent years, a noticeable shifting from conventional fossil fuels to renewable energy based systems has embarked electrochemical splitting of water as the most promising way to produce clean energy of hydrogen. Generally, the lack of active and stable electrocatalysts for oxygen evolution reaction (OER) limits the practicability of water splitting as a renewable source of energy. In this work, interconnected 3D structure of cobalt oxides nanoparticles (Co3O4 NPs) derived from ZIF-67 with nitrogen-doped carbon nanotubes (N-CNTs) of polypyrrole (PPy) origin is successfully synthesized as OER electrocatalysts. Impressively, the highly conductive N-CNTs that run through the Co3O4 NPs not only endow the resulting product Co3O4/N-CNTs with large active surface area and enhanced charge transfer between Co3O4 NPs, but also prevent Co3O4 NPs from aggregation. As a result, the as-synthesized Co3O4/N-CNTs electrocatalyst exhibits outstanding OER activity with a low onset potential of ~1.37 V (vs RHE), overpotential of only 200 mV to attain a stable current density of 10 mA cm−2 in basic media and very small Tafel slope of 40 mV dec−1. Moreover, the enhanced nitrogen-content also improves the OER kinetics by proficient charge transfer. The superb electrocatalytic performance and higher stability make the Co3O4/N-CNTs a proficient non-precious electrocatalyst for the OER.

中文翻译：

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新设计的 ZIF-67/PPy NTs 复合材料衍生的 Co3O4/N-CNTs 的 OER 性能提高

摘要 近年来，从传统的化石燃料到基于可再生能源的系统的显着转变已经开始将水的电化学分解作为生产清洁氢能源的最有前途的方式。通常，缺乏活性和稳定的析氧反应（OER）电催化剂限制了水分解作为可再生能源的实用性。在这项工作中，从 ZIF-67 衍生的钴氧化物纳米粒子 (Co3O4 NPs) 的互连 3D 结构与聚吡咯 (PPy) 来源的氮掺杂碳纳米管 (N-CNTs) 被成功合成为 OER 电催化剂。令人印象深刻的是，贯穿 Co3O4 NPs 的高导电性 N-CNT 不仅赋予所得产物 Co3O4/N-CNTs 大的活性表面积和增强的 Co3O4 NPs 之间的电荷转移，还可以防止 Co3O4 NPs 聚集。因此，合成的 Co3O4/N-CNTs 电催化剂表现出出色的 OER 活性，起始电位低至 ~1.37 V（vs RHE），过电位仅为 200 mV 即可获得 10 mA cm-2 的稳定电流密度。基本介质和 40 mV dec−1 的非常小的 Tafel 斜率。此外，提高的氮含量还通过熟练的电荷转移改善了 OER 动力学。卓越的电催化性能和更高的稳定性使 Co3O4/N-CNTs 成为 OER 的熟练非贵重电催化剂。此外，提高的氮含量还通过熟练的电荷转移改善了 OER 动力学。卓越的电催化性能和更高的稳定性使 Co3O4/N-CNTs 成为 OER 的熟练非贵重电催化剂。此外，提高的氮含量还通过熟练的电荷转移改善了 OER 动力学。卓越的电催化性能和更高的稳定性使 Co3O4/N-CNTs 成为 OER 的熟练非贵重电催化剂。