| Among the numerous catalytic hydrogen evolution materials,molybdenum disulfide?MoS2?has become a research hotspot because of its properties of low cost,abundant earth reserves and relatively high catalytic activity.In this research,nickel diphosphate?Ni2P?with the excellently conductive characteristics was combined with MoS2 by a hydrothermal synthesis process in order to further improve the catalytic activity of MoS2.Thus three kinds of MoS2/Ni2P hybrids?38 wt%Ni2P addition for MoS2/Ni2P-38,50 wt%Ni2P addition for MoS2/Ni2P-50 and 58 wt%Ni2P addition for MoS2/Ni2P-58?were prepared successfully.Then the crystalline properties,morphology,chemical composition and specific surface area of them were characterized.Also,the electrochemical hydrogen evolution reaction?HER?performances of fabricated hybrids were evaluated by electrochemical measurement techniques.The results showed that molybdenum disulfide and nickel diphosphate can combine together during the hydrothermal synthesis process.The addition of Ni2P is benefit for the increase in the electronic conductivity between layers and domains of MoS2,and the catalytic hydrogen evolution of MoS2 can be distinctively enhanced.Among the three hybrids,the MoS2/Ni2P-50 possesses the most uniform mixed morphology of MoS2 and Ni2P.Besides,this hybrid demonstrates the largest specific surface area compared with other two hybrid samples.Although the hydrogen evolution properties of the three hybrids?MoS2/Ni2P-38,MoS2/Ni2P-50 and MoS2/Ni2P-58?are inferior to those of pure Ni2P,they are higher than that of MoS2 to some extent.In comparison with other two hybrids,MoS2/Ni2P-50 has the best hydrogen evolution performance,and shows the HER features as follows:the highest cathodic hydrogen evolution current of 70 mA/cm2 at 0.368 V vs.RHE,the minimum tafel slope of 58 mV·decade-1,and the smallest charge transfer resistance of 1239?·cm2.In addition,in order to solve the disposal problem of ineffective spent hybrids,the tribological properties of MoS2,Ni2P and MoS2/Ni2P-50 as enforced additives incorporated into polyvinylidene fluoride?PVDF?were further investigated.First,MoS2/PVDF,Ni2P/PVDF and MoS2/Ni2P-50/PVDF composites were prepared.Then the effects of different doping components on the tribological properties of PVDF matrix composites were investigated under the optimal loading of 100 N and the optimum speed of 3 Hz?equivalent to the condition of linear velocity of 0.08262 m/s?.The crystallization properties,the apparent morphology and functional groups of the composites were also characterized.The results show that the addition of MoS2 can not improve the friction and wear resistance of PVDF,while the addition of Ni2P and MoS2/Ni2P-50 can improve the tribological properties of this polymer.Particularly,the Ni2P addition is explicitly advantageous to the increment in wear resistance and friction reduction property of PVDF. |
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