Preparation Of Molybdenum Disulfide Composite Material And Study On Its Electrocatalytic Hydrogen Evolution Performance

The limited reserves of fossil fuels and the environmental pollution caused by their combustion are becoming more and more serious,which has promoted the demand and development of renewable clean energy.Hydrogen,an ideal clean energy source,is a demand for efficient,environmentally friendly and inexpensive hydrogen production technology.Hydrogen produced by electrolyzed water is the first choice for industrial green hydrogen production because it does not produce harmful gases such as CO₂.Pt is the best cathode catalyst,but its high cost and low reserves limited the large-scale application of industrial hydrogen production.Therefore,it is extremely urgent to develop non-precious metal catalysts with good performance and abundant reserves.MoS₂ exhibits the excellent electrochemical hydrogen evolution performance,but it still needs to be improved compared with Pt.In this paper,the electrochemical hydrogen production performance of the material in an acidic medium is further improved by preparing MoS₂ with suitable morphology and compounding it with different metal oxides.The specific research contents are as follows:?1?The suitable reaction conditions for the preparation of MoS₂ nanotubes by a simple solvothermal method were as follows:reaction at 200°C for 24 h.The electrochemical hydrogen evolution performance of MoS₂ nanotube catalyst was investigated in acidic medium.It was found that the MoS₂ nanotube catalyst only required an overpotential of 0.32 V at a current density of-10 mA/cm² and the Tafel slope of 69 mV/dec,as well exhibits good electrochemical stability.Compared with MoS2 flower balls,MoS2 nanotubes exhibit the higher electrocatalytic hydrogen evolution performance due to its smaller charge transfer impedance and the more active sites exposured.?2?The TiO₂/MoS₂ composites prepared by the low-temperature reduction method showed the better electrochemical hydrogen evolution activity and stability in acidic medium:TiO2/MoS2 composites have the best electrocatalysis hydrogen evolution performance when the mass percentage of TiO₂ and MoS₂ is 10%.a smaller Tafel slope of 36 mV/dec,and the TiO₂/MoS₂ composite catalyst requires only an overpotential of 0.21 V when the current density of electrocatalytic hydrogen evolution was-10 mA/cm².The high electrocatalytic hydrogen evolution performance of TiO₂/MoS₂ composites was not only caused by the morphology of MoS₂ nanotubes,but also by the electric double layer effect and the reduced electron transfer internal resistance produced by the recombination.?3?The CeO₂/MoS₂ composites were prepared by the solvothermal method and investigated its electrochemical hydrogen evolution performance.The principle of promoting the electrochemical hydrogen evolution of MoS2 catalysts by CeO2 was also discussed.It is found that the CeO₂/MoS₂ composite exhibits the better electrochemical hydrogen evolution activity and stability in an acidic medium,the Tafel slope was only40 mV/dec,and when the current density of electrocatalytic hydrogen evolution was-10 mA/cm²,the CeO₂/MoS₂ composites catalyst required only an overpotential of0.20 V.The reason why CeO₂ improves the electrocatalytic hydrogen evolution activity and stability of MoS₂ nanotubes is mainly to accelerate the desorption of intermediates in the hydrogen evolution reaction and reduce the electron transfer internal resistance of composites.