Ni-Mo_(2)N/NF的制备及其电催化析氢活性

Preparation of Ni-Mo_(2)N/NF electrode and its performance in electro-catalytic hydrogen evolution

采用简单、高效的方法,成功制备了应用于碱性介质电催化制氢的Ni-Mo_(x)N_(y)/NF电极,对其进行XRD、SEM、TEM和XPS表征,并系统研究了该电极的电催化析氢性能。结果表明:产物的相组成物为单质Ni、Mo_(2)N及Mo_(5)N_(6)。控制工艺条件,可制备出性能最佳的相结构为Ni-Mo2N,Mo5N6的含量增加不能提高产物的性能;性能最佳试样的显微形貌呈现纳米棒状,Ni(111)与Mo_(2)N(200)构成的异质结构界面赋予材料优异的电催化析氢性能,在碱性电解质中,10 mA/cm^(2)下析氢过电位达21 mV,接近20%Pt/C电极(18 mV),Tafel斜率为39.9 mV/dec。电极的优异性能既来源于高电化学活性面积,也来源于其高本征活性,跻身当前性能最佳的非贵金属催化材料,为非贵金属碱性析氢电催化材料的研发提供了新思路。

The Ni-Mo_(x)N_(y)/NF nano composite electrodes applied in electro-catalytic hydrogen evolution reaction(HER)in alkaline electrolyte were prepared by a simple and efficient process.The structures of the Ni-Mo_(x)N_(y)/NF electrodes were characterized by XRD,SEM,TEM and XPS methods,and the electro-catalytic HER activities of the electrodes were tested systematically.Results show that the crystal structure of the product was composed of Ni,Mo_(2)N and Mo_(5)N_(6),and the best phase composition is Ni and Mo_(2)N,which showed the best electro-catalytic HER activity among all samples.The Ni and Mo_(2)N could be acquired by controlling the temperature and duration during the thermo nitridation process,meanwhile the content increase of Mo_(5)N_(6)could not increase the performance of the electrodes.The Ni-Mo2N/NF sample has the morphology of nanorods.The heterostructure interface between Ni(111)crystal and the Mo_(2)N(200)gives the material excellent properties in HER.The Ni-Mo2N/NF reaches an overpotential of 20 mV at 10 mA/cm^(2),approximating 20%Pt/C electrode(18 mV),with a small tafel slope of 39.9 mV/dec in alkaline electrolytes.The excellent performance of the electrodes comes from both the abundant electrochemical activity area and its high intrinsical activity,making it one of the best non-precious metal catalytic materials.It provides a new idea for the research and development of non-precious metal alkaline hydrogen evolution electrocatalytic materials.