Experimental Investigation Of Nickel Phosphorus/Molybdenum Disulfide Composites For Hydrogen Evolution Reaction

In recent years,with the over exploitation and combustion of fossil fuels,some environmental pollution problems appear frequently,which have seriously affected the normal life of the people in our country.In order to alleviate the energy crisis and environmental problems caused by the depletion of traditional fossil fuels,hydrogen as a very attractive clean energy has attracted wide attention.However,in all of the preparation of hydrogen technology,the electrochemical hydrogen system possesses the characteristics of simple operation and mature technology,and have the extremely prospect of application.In this research,the Ni-P/MoS2 composites were fabricated by anchoring the electroless plating on the surface of molybdenum disulfide,which was prepared by hydrothermal method firstly.And the HER activities of all the as-prepared composites were tested in alkaline solution.The results illustrate that the pure MoS2 shows an inferior conductive performance acting as a semiconductor material.However,after the pretreatment of MoS2 powders in three different nickel-phosphorus(Ni-P)solutions,the obtained Ni-P/MoS2 composites possess both characteristics of flower edge and good conductivity.Moreover,the three series of Ni-P/MoS2 composites exhibit a relative higher hydrogen evolution activities than pure MoS2 and the HER activities of the samples following the trend: Ni-MP/MoS2 ?Ni-HP/MoS2 ? Ni-LP/MoS2 ? MoS2.In all samples,Ni-MP/MoS2-0.5h performs the remarkable HER performance with the largest cathodic hydrogen current density 56.90×10-5 A/cm2,the most number of active sites 4.21×10-8 mol/cm2,the lowest Tafel ratio 57mV/decade and impedance value 45.13 ? cm2.In addition,the main mechanism of enhancing the HER property can be attributed to the coating enhance the electronic conductivity of MoS2 between inter-layers and inter-domain.What's more,the electroless Ni-P coating make up for the defects that lacking of active sites at the inertia surface center of MoS2 and bring an overall increase of active sites for MoS2.Besides,the existence of some metastable phase phosphide greatly improve the catalytic activity of the composite material.