Efficient water splitting is limited by the sluggish oxygen evolution reaction (OER) to a large extent, which inhibits the development of sustainable energy and has attracted widespread attention. In this work, a type of microsized Cu-based metal–organic framework (MOF) of Cu-BTB has been successfully synthesized by a rapid reaction within half an hour. During the subsequent pyrolysis, a large number of N-containing carbon nanotubes (NCNTs) are grown on the entire surface of hierarchically porous MOF-derived nanosized carbons through the introduction of ethylene and ammonia, denoted as NCNT/Cu/C. After oxidation, NCNT-supported nanosized copper oxide embedded in a carbon matrix (NCNT/CuO/C) is finally obtained to show the preserved morphology and high graphitization degree. The high specific surface area and conductivity of NCNTs for NCNT/CuO/C further enable the electrolyte to make better contact with the active materials during the OER. Finally, the optimal nanosized NCNT/CuO/C exhibits a high degree of improvement in OER performance, in which it attains an overpotential of only 369 mV at 10 mA cm^–2, and its Tafel slope is calculated to be 87.4 mV dec^–1, indicating fast reaction kinetics. The demonstrated work proves that the method of doping NCNTs with nanosized copper oxides can effectively enhance the efficacy of water oxidation, which can be further used in future energy applications.

中文翻译：

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在氧化铜纳米粒子修饰的多孔碳微粒上生长的碳纳米管用于水氧化

高效的水分解在很大程度上受到缓慢的析氧反应（OER）的限制，阻碍了可持续能源的发展，受到了广泛关注。在这项工作中，通过半小时内的快速反应成功合成了一种微尺寸的Cu基金属有机骨架（MOF）Cu-BTB。在随后的热解过程中，通过引入乙烯和氨，在分级多孔 MOF 衍生的纳米碳的整个表面上生长了大量含 N 的碳纳米管 (NCNT)，表示为NCNT/Cu/C。氧化后，NCNT 负载的纳米级氧化铜嵌入碳基体 ( NCNT/CuO/C) 最终得到显示出保留的形态和高石墨化程度。NCNT/CuO/C的 NCNT 的高比表面积和电导率进一步使电解质在 OER 过程中与活性材料更好地接触。最后，最佳纳米尺寸的 NCNT/CuO/C在 OER 性能方面表现出高度的改进，其中它在 10 mA cm ^{–2 下}达到仅 369 mV 的过电位，其 Tafel 斜率计算为 87.4 mV dec ^–1，表明快速反应动力学。所展示的工作证明，用纳米级氧化铜掺杂 NCNT 的方法可以有效提高水氧化的功效，可进一步用于未来的能源应用。