Preparation Of Metal-supported Molybdenum Disulfide Electrocatalytic Material By High Gravity Method And Its Hydrogen Evolution Performance

Hydrogen energy is one of the most promising new energy sources due to its advantages of cleanliness,high energy density,and wide application ranges.Molybdenum disulfide(MoS2)is a good hydrogen evolution catalyst for hydrogen production by electrolysis of water.It shows low cost and good stability,which are contributed to a large number of active sites on the edge.However,its easy agglomeration,the incomplete exposure of active sites,and poor conductivity are,not conducive to the electrocatalytic hydrogen evolution reaction.It can adopt metal doped MoS2 technology to improve its in-plane activity and conductivity.However,in the reported metal-doping literatures,the precious metal Pt-doping effect is better,whereas,it has low earth abundance and expensive,and the non-Pt precious metal elements are low in cost but not excellent in performance.In view of the fact that Ru is a precious metal of the Pt group,it has excellent electrocatalytic performance and relatively low price compared to Pt.Co metal is a non-noble metal and can improve the electrocatalytic performance of MoS2 at the same time.Ru and Co metal supports are selected.In this thesis,the traditional hydrothermal method and high-gravity technology are used to prepare two-dimensional flake MoS2,and load doped Ru and Co metal particles in situ to prepare Ru-MoS2,respectively.CoRu-MoS2 composite electrocatalytic materials,and study the effect of preparation process conditions on influence of composite materials on the performance of electrocatalytic hydrogen evolution.The main research contents and conclusions of the thesis are as follows:Two-dimensional flake MoS2 was prepared by traditional hydrothermal method,and ruthenium trichloride(RuCl3)was used as the ruthenium source,and the Ru-MoS2 composite electrocatalytic material was prepared in situ by high gravity method.The effect of the preparation process conditions on the hydrogen evolution performance of Ru-MoS2 electrolysis water was studied:the use of high gravity internal circulating rotating bed,Ru/Mo mass ratio is 1:10,the reaction time is about 30 min,and the reaction time is 30 min.The temperature is 60℃ and the feed flow rate is 8.7 mL/min.The prepared two-dimensional flaky MoS2 owns a size of about 150 nm.Ru is uniformly supported on the MoS2 flaky structure in the form of particles,with an average particle size of 1.7 nm.In 1 M KOH electrolyte,the overpotential of the Ru-MoS2 composite material drops from 325 mV to 29 mV to achieve the HER current density of 10 mA cm-2,and the Tafel slope drops from 119.4 mV dec-1 to 40.0 mV dec-1.Compared with commercial Pt/C(overpotential 34 mV,tafel slope 61.5 mV dec-1),it shows good electrocatalytic hydrogen evolution performance.Using the flake MoS2 prepared above as the carrier,RuCl3 as the ruthenium source,and CoCl2·6H2O as the cobalt source,the CoRu-MoS2 composite electrocatalyst was prepared by high gravity technology.The average particle size of Ru is about 1.3 nm,which is smaller than those of Ru-MoS2.Compared with the single-doped Ru catalytic material,the double-doped material endow better electrocatalytic hydrogen evolution performance.When the amount of Co/Mo is 5-wt%,the overpotential of 21 mV can achieve the current density 10 mA cm-2 in 1 M KOH electrolyte,and the Tafel slope is 44.1 mV dec-1.