Prepation Of Foam Hydrogenevolution Electrodes And Study Of Their Hydrogen Evolution Behavior

With the decreasing of oil, coal et. fossil fuels,and the serious environmentalproblems caused by burn them. New energy such as hydropower, nuclear, solar, windwas get more and more attention. But these energy was usually converted to electricitywhich was hard to store. So a secondary energy to store these new storage is necessary,and hydrogen is the ideal one. Hydrogen can be stored in gas, liquid, solid, it can beuse as fuel or make into fuel cell. But the high overpotential in water electrolysis wasthe biggest problem we must overcome. In this paper, Ni-Mo-W, Ni-Mo-Co alloyelectrode and Mo/Ni-Mo composite electrode were prepared, their electrocatalyticcharacteristics for HER in30%KOH solution were investigated by Tafel curve, EIS.Their morphology, crystalline, component characteristics were detected by SEM,XRD,EDS.Ni-Mo-W, Ni-Mo-Co alloy electrodes were prepared by electrodeposition. Theinfluence of all technics parameters on the catalytic activity of hydrogen evolution ofNi-Mo-W, Ni-Mo-Co alloy electrodes were studied systematically, then the optimaltechnics parameters for preparation of the electrodes were fixed. The performance ofNi-Mo-W, Ni-Mo-Co alloy electrodes, which prepared under optimal technicsparameters, was studied. SEM observation showed that W, Co make the film muchsmooth, the addition of Co can reduce the crack of film. EDS analysis show thecomposition of Ni-Mo-W, Ni-Mo-Co alloy was Ni82.3Mo16.9W0.78and Ni87.6Mo5.2Co7.1.The XRD result show Ni-Mo-W, Ni-Mo-Co alloy’s crystals were much small. Theoverpotential η200of Ni-Mo-W and Ni-Mo-Co is10mV lower than Ni-Mo.The Mo/Ni-Mo composite electrode was prepared by composite plating, thecharacteristics of this electrode were examined by SEM, EIS, Tafel cure. SEMobservation showd that the surface of the composite electrode had numerous ofprojections, which greatly enlarged the specific surface area of the electrode. EISresult showed the faradaic impedance is0.383Ω cm2, the diffuse impedance was1.021Ω cm2, that mean the diffuse step was control step. The Tafel cure showed, theoverpotential η200of Mo/Ni-Mo composite electrode was202mV, which was50mVlower than Ni-Mo alloy electrode.The hydrogen evolution behavior of foam nickel electrode, bright nickel electrode,bright molybdenum electrode, Ni-Mo alloy electrode, Mo/Ni composite electrodes wasstudied by using electrochemical measurement methods. The open circuit potential- time of foam nickel electrodes showed that both hydrogen molecules and hydrogenatom can be adsorbed by the surface of foam nickel. The EIS of Mo/Ni compositeelectrodes at different temperature showed the number of adsorbed hydrogen atomclosely related to the hydrogen-evolution activity of electrode.