Chemical Industry and Engineering Progress ›› 2024, Vol. 43 ›› Issue (1): 465-472.DOI: 10.16085/j.issn.1000-6613.2023-0213

• Materials science and technology • Previous Articles    

Electrocatalytic hydrogen evolution performance of nitrogen-doped molybdenum disulfide nanocatalysts

YANG Chenggong1,2(), HUANG Rong1,2, WANG Dong’e1(), TIAN Zhijian1()   

  1. 1.Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
    2.University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2023-02-17 Revised:2023-03-28 Online:2024-02-05 Published:2024-01-20
  • Contact: WANG Dong’e, TIAN Zhijian

氮掺杂二硫化钼纳米催化剂的电催化析氢性能

杨成功1,2(), 黄蓉1,2, 王冬娥1(), 田志坚1()   

  1. 1.中国科学院大连化学物理研究所,辽宁 大连 116023
    2.中国科学院大学,北京 100049
  • 通讯作者: 王冬娥,田志坚
  • 作者简介:杨成功(1995—),男,博士研究生,研究方向为纳米硫化钼催化剂的合成及应用。E-mail:cgyang@dicp.ac.cn
  • 基金资助:
    新疆维吾尔自治区重点研发计划(2017B02007-1);国家自然科学基金面上基金(22272168);中国科学院大连化学物理研究所创新基金青年基金(DICP I202235)

Abstract:

A series of nitrogen-doped MoS2 (N-MoS2) nanocatalysts were synthesized by hydrothermal method with sodium molybdate as molybdenum source, L-cysteine as sulfur source and reducing agent, and dicyandiamide as nitrogen source. The crystal structure, morphology, elemental mapping and electronic properties of N-MoS2 with different N doping contents were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The characterization results revealed that all synthesized N-MoS2 catalysts were flower-like spheres composed of nanosheets, and N atoms were successfully doped into MoS2 lattice and uniformly distributed in the N-MoS2 nanocatalysts. The doping of N atoms increases the electron densities of Mo and S atoms adjacent to N atoms, and forms more unsaturated coordination sites with high catalytic activity. The linear sweep voltammetry curves and the Tafel slopes of all catalysts were tested in acidic medium with an electrochemical workstation to evaluate their electrocatalytic hydrogen evolution (HER) performance. The results suggest that the hydrogen evolution reactions on MoS2 catalyst and N-MoS2 catalysts both proceed via the Volmer-Heyrovsky mechanism, but the rate-determining step of MoS2 catalyst is Volmer reaction, and that of N-MoS2 catalysts is Heyrovsky reaction. Compared with MoS2 catalyst, N-MoS2 catalysts exhibit better HER performance with lower Tafel slopes and faster hydrogen evolution reaction rates. Especially, N-MoS2-0.1 (N/Mo=0.1) exhibits the lowest Tafel slope of 60mV/dec. The improved HER activity of N-MoS2 nanocatalysts mainly results from the increased exposure of unsaturated coordination sites and the weakening of Mo-H* due to the electron-rich Mo atoms.

Key words: nitrogen doping, molybdenum disulfide, catalyst, electrochemistry, hydrogen

摘要:

以钼酸钠为钼源,L-半胱氨酸为硫源和还原剂,双氰胺为氮源,采用水热法合成了一系列氮掺杂二硫化钼纳米催化剂(N-MoS2)。通过XRD、SEM、XPS、Raman等手段表征了不同N掺杂量的N-MoS2催化剂的形貌、元素分布、晶体结构和电子性质。表征结果表明,合成的N-MoS2催化剂均为纳米片层组成的花球,N原子均匀掺杂进了MoS2晶格中。N掺杂使得N原子周围的Mo和S原子的电子密度增加,生成更多具有催化活性的不饱和配位点。采用电化学工作站在酸性介质中测试了催化剂的线性扫描伏安曲线和塔菲尔斜率,评价了N-MoS2纳米催化剂的电催化析氢(HER)性能。结果表明,MoS2催化剂和N-MoS2催化剂上的析氢反应均通过Volmer-Heyrovsky路径进行。MoS2催化剂上析氢反应速控步骤为Volmer反应,N-MoS2催化剂上析氢反应的速控步骤为Heyrovsky反应。与MoS2催化剂相比,N-MoS2催化剂的塔菲尔斜率较低,析氢反应速率较快,显示出更好的电催化析氢性能。尤其当N与Mo的原子为0.1时(N/Mo=0.1),制备的N-MoS2-0.1催化剂表现出最好的电催化析氢性能,其塔菲尔斜率为60mV/dec。N-MoS2催化剂的电催化活性提高可归结为不饱和配位点暴露量的增加和富电子的Mo对Mo-H*的弱化。

关键词: 氮掺杂, 二硫化钼, 催化剂, 电化学,

CLC Number: 

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