MoS_(2)/Mo_(x)N异质结构的制备及其电催化析氢性能研究

Preparation of MoS_(2)/Mo_(x)N heterostructures andtheir electrocatalytic hydrogen evolution performance

二硫化钼纳米片(MoS_(2))是一种有望取代贵金属材料、非常有前景的电催化析氢材料。MoS_(2)不足在于导电性较差,析氢反应(HER)能垒较高。为了克服这一缺点,我们引入制备简单、导电性良好的Mo_(2)N作为基体。通过水热法,将MoS_(2)纳米片均匀生长在Mo_(2)N颗粒表面,一方面增加了材料导电性,另一方面MoS_(2)与Mo_(2)N形成MoS_(2)/Mo_(x)N异质结构有效增强水分子的解吸,从而提高HER性能。利用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)、电化学工作站对MoS_(2)/Mo_(x)N进行结构、形貌以及性能的表征。实验结果表明,MoS_(2)纳米片均匀生长在Mo_(2)N颗粒表面,形成异质结构,水热12 h所得材料性能最佳。以MoS_(2)/Mo_(x)N作为工作电极,碳棒与Ag/AgCl电极分别作为对电极和参比电极,进行HER测试。在-10 mA/cm^(2)下过电位仅为248 mV,Tafel斜率为93.5 mV/dec,稳定性良好。

Molybdenum disulfide(MoS_(2))nanosheets are a promising electrocatalytic hydrogen evolution material that is expected to replace noble metal materials.The disadvantage of molybdenum disulfide is poor electrical conductivity and high energy barrier for hydrogen evolution reaction(HER).To overcome this shortcoming,we introduce Mo_(2)N,which is simple to prepare and has good conductivity,as a matrix.By the hydrothermal method,MoS_(2)nanosheets were uniformly grown on the surface of Mo 2N particles,which on the one hand increased the conductivity of the material,and on the other hand,the MoS_(2)/Mo_(x)N heterostructure formed by MoS_(2)and Mo_(2)N effectively enhanced the desorption of H_(2)O,thereby improving the HER performance.The structure,morphology and properties of MoS_(2)/Mo_(x)N were characterized by X-ray diffractometer(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM)and electrochemical workstation.The experimental results show that MoS_(2)nanosheets grow uniformly on the surface of Mo_(2)N particles to form a heterostructure,and the material obtained by hydrothermal treatment for 12 h has the best performance.MoS_(2)/Mo_(x)N was used as the working electrode,and the carbon rod and Ag/AgCl electrode were used as the counter electrode and the reference electrode,respectively,for the HER test.The overpotential is only 248 mV at-10 mA/cm^(2),the Tafel slope is 93.5 mV/dec,and the stability is superior.