The Preparation And Study Of Composite Cathodes For Hydrogen Evolution In Alkaline Medium

As a clean energy, hydrogen energy has been widespread concerned under thesituation of increasingly serious environmental pollution. Alkaline water electrolysisis the most mutual technology of use renewable resources to produce hydrogen.However, the lower energy efficiency and higher energy consumption limit theapplication of this technology.Surface modification to cathode is an effective method to improve energyefficiency by reduce overpotential of hydrogen evolution reaction（HER）. Compositeelectrodeposition can deposite active materials on electrode and increase the realelectrode surficial area, which lead to an lower HER overpotential.In the field of use composite electrodeposition technology to prepared cathodes,researchers always pay more attention to the improvement on geometric factor of theelectrodes, while ignore to apply the achievement in activated alloy cathodes studies.In this paper we combined composite electrodeposition technology and activated Ni-Salloy cathode study, and prepared Ni-S/Ni-S-Mo and Ni-S/Ni-MoS₂electrodes onnickel foil or nickel foam. Also we discussed the influence of solution composition,particle size and deposition process conditions on electrode performance, andinvestigated the impact of the interlayer on electrode stability.The experimental results show that for Ni-S/Ni-S-Mo electrode when theconcentration of thiourea in Ni-S solution was25g·L^-1，thiourea, Mo particles andNiSO₄concentration in Ni-S-Mo solution were25g·L^-1,8g·L^-1and100g·L^-1respectively the electrode showed the best comprehensive performance, and Ni-Sinterlayer and smaller Mo particle size help to improve electrode stability. We got thebest deposite conditions for Ni-S/Ni-S-Mo nickel foam electrode with the currentdensity30mA·cm^-2and deposite time10min in Ni-S stage, current density50mA·cm^-2and deposite time30min in Ni-S-Mo stage,40℃for electrolyte solution. ForNi-S/Ni-MoS₂nickel foam electrode, the best deposite conditions were currentdensity24mA·cm^-2and deposite time15min in Ni-S stage, current density32mA·cm^-2and deposite time45min in Ni-MoS₂stage,40℃for electrolyte solution.We compared the Ni-S/Ni-S-Mo and Ni-S/Ni-MoS₂electrodes to Ni-S-Mo ternary alloy electrode prepared as industrial method in electrolysis experiment.Results show that Ni-S/Ni-S-Mo and Ni-S/Ni-MoS₂electrodes showed better stability.