MoS_(2)/Ru异质结构的制备及其电催化析氢反应性能EI北大核心CSCD

二维层状二硫化钼(MoS_(2))是一种非常有前景的替代贵金属铂的电水解制氢催化剂。然而,MoS_(2)电子导电性较差,且在碱性氢析出反应(HER)中对水分子吸附/裂解的活化能垒较高,限制其在碱性电水解的应用。通过一步水热法将MoS_(2)纳米片均匀生长在三维导电碳布(CC)上,以有效提高电极导电性。随后在RuCl_(3)的乙醇溶液中通过溶剂热法可控制备超小Ru纳米颗粒负载MoS_(2)纳米片,形成CC@MoS_(2)/Ru异质结构。Ru的负载能有效促进水吸附/裂解反应,从而和MoS_(2)协同催化HER。采用X射线粉末衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等方法对MoS_(2)/Ru进行结构和形貌表征。结果表明:MoS_(2)呈纳米片状交错生长在碳布上,并且超小Ru纳米颗粒(平均粒径2.5 nm)均匀负载在MoS_(2)纳米片上。将CC@MoS_(2)/Ru作为工作电极,石墨棒和Hg/HgO电极分别为对电极和参比电极进行碱性HER测试。在电流密度为-10 mA·cm^(-2)下的过电位仅为71.3 mV,Tafel斜率为104.8 mV·dec^(-1)。通过对其进行计时电位滴定法稳定性测试,发现在恒电流密度-10 mA·cm^(-2)下能够维持至少35 h而没有明显性能衰减。

Synthesis and electrochemical hydrogen evolution reaction properties of MoS2/Ru heterostructures

Two-dimensional layered MoS₂ is considered to be a promising electrocatalyst alternative to Pt for water splitting. However, low electronic conductivity and high energy barrier of water adsorption/dissociation of MoS₂ during alkaline hydrogen evolution reaction (HER) limit its application in water splitting. In this work, the smoothly anchored of MoS₂ nanosheet on carbon cloth (CC) was prepared by one-pot hydrothermal method. The CC can significantly improve the electronic conductivity. Subsequently, the MoS₂ nanosheet supported ultra-small Ru nanoparticles were controllably prepared by solvothermal reaction through immersing CC@MoS₂ in an ethanol solution containing RuCl₃ and finally formed CC@MoS₂/Ru heterostructure. Ru can promote water adsorption/dissociation, and then synergistically catalyze HER with MoS₂. The CC@MoS₂/Ru is characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM), etc. The results show that the MoS₂ nanosheets crossedly aligned on the CC, and the ultra-small Ru nanoparticles (average grain diameter of 2.5 nm) are dispersed homogeneously on the MoS₂ nanosheets. The CC@MoS₂/Ru is working electrode, the graphite rod and Hg/HgO are counter and reference electrodes, respectively. The alkaline HER are tested and the overpotential is only 71.3 mV to achieve the current density of -10 mA·cm^-2, the Tafel slope of CC@MoS₂/Ru is 104.8 mV·dec^-1. The chronopotentiometry is performed at -10 mA·cm^-2 to evaluate the stability of CC@MoS₂/Ru. After the 35 h, the neglectable potential attenuation can be observed.