| Nowadays,energy scarcity and environmental problems faced a severe test.Among them,electrochemical transformation and storage technology are important ways to solve the problems.The design of high performance hydrogen evolution electric catalyst and storage materials plays an important role for the application of hydrogen energy.Scholars studied the two-dimensional materials extensively in recent years.Molybdenum disulfide（Mo S2）as a member of the two-dimensional materials,shows a lot of interesting electrical and optical properties.These qualities provide the feasibility for exploring new electric catalyst and energy storage materials.This paper aims to analyze the factors that molybdenum disulfide（Mo S2）is restricted to become the efficient electrochemical energy conversion and storage materials.In order to achieve its more efficient electrochemical properties,we attempt to enhance the catalytic activity sites of hydrogen evolution electric catalyst and electrical conductivity.At the same time we explore the electrochemical influences that the electro-catalysis performance of molybdenum disulfide act on La-Y-Ni hydrogen storage material and enlarge molybdenum disulfide（Mo S2）application ranges in energy storage materials.We get the following conclusions through experiment researches:1、Ammonium molybdate and thiourea were molybdenum source and sulfur source.We synthesized flower flakes by hydrothermal-method（220 ℃、18 hours）and discussed the effect of the reaction temperature and the reaction hours.Experimental results show that we compound good crystallinity molybdenum disulfide by hydrothermal at 220 ℃ 18 hours.With the increase of reaction time,the crystallinity of nanosheets change slightly but affect the dispersion degree.At the same reaction time（24 hours）,the crystallinity of nanosheets improve obviously with the increase of reaction temperature.With the electrochemical tests,the Mo S2 nanosheets,with220 ℃18 hours hydrothermal method,exhibit low HER onset overpotential as well as large cathodic current density of 54.8 m A cm-2（at 400 m V overpotential）and small Tafel slope of 72 m V decade-1,revealing the significant enhancement of the electrocatalytic performance.2、We try to exfoliate molybdenum disulfide nanosheets which were obtained by hydrothermal-method in 220 ℃ 18 hours through high speed vibration ball mill.In order to obtain uniform layer distribution and excellent crystal structure product,weuse classification centrifuge method.Experimental results show that the best exfoliation efficiency can be obtained through a low boiling point of ethanol/water solvent 、 100:1 ball material ratio and 8 hours ball mill time.The molybdenum disulfide nanosheets with uniform 2-3 layer S-M-S structure can be obtained when the ball milling time is 8 hours 、 20 min centrifugation time at 10000 rpm.The crystal structure is favorable with no damage.3、The molybdenum disulfide / La-Y-Ni composite material were prepared by planetary ball-mill under different molybdenum disulfide mass ratio of 0.2,0.5,1.0and 3.0.Then we explored the affect of Mo S2 on hydrogen storage alloys electrochemical performance.Experimental results show that hydrogen evolution reaction of molybdenum disulfide can reduce the maximum discharge capacity of the composite material intensively.With the increases of Molybdenum disulfide mass ratio in composite materials,when the mass ratio is 1.0,the capacity retention rate of the composite electrode reaches 26.6% at a discharge current density of 2400 m A g-1,which is 3 times that of bare alloy.With the comprehensive electrochemical testing results,1.0 and 3.0 mass ratio composite material exhibit higher exchange current density and hydrogen diffusion coefficient compared with the bare alloy,playing the crucial effect of HRD performance. |
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