Abstract Cobalt-encapsulated in nitrogen-doped carbon nanotubes (Co-NCNT) were prepared by hydrothermal method. CoCl2·6H2O and graphitic carbon nitride (g-C3N4) were used as raw material. Samples containing such defective structures were synthesized by hydrothermal methods, while there is an excellent synergistic effect between cobalt nanoparticles and carbon nanotubes on hydrogen evolution reaction (HER). In order to improving the HER performance, different samples were fabricated by changing the molar ratio of raw materials and pyrolysis temperature. The results show that Co-NCNT has the best HER performances at the ratio of CoCl2·6H2O and g-C3N4 (1:7) when the pyrolysis temperature reached 700 °C. The overpotential has reached 285 mV when the current density is 10 mA·cm−2, the Tafel slope of the sample is 103 mV·dec−1.

中文翻译：

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水热法制备的氮掺杂碳纳米管中包封钴作为析氢催化剂

摘要 采用水热法制备了钴包覆氮掺杂碳纳米管（Co-NCNT）。以CoCl2·6H2O和石墨氮化碳(g-C3N4)为原料。含有这种缺陷结构的样品是通过水热法合成的，而钴纳米颗粒和碳纳米管之间对析氢反应（HER）有极好的协同作用。为了提高HER性能，通过改变原料摩尔比和热解温度制备了不同的样品。结果表明，当热解温度达到700℃时，Co-NCNT在CoCl2·6H2O和g-C3N4(1:7)的比例下具有最好的HER性能。当电流密度为10 mA·cm-2时，过电位达到285 mV，样品的Tafel斜率为103 mV·dec-1。