Preparation Of Porous Nickel Phosphide Electrode By Electrodeposition And Study On Hydrogen Evolution Performance

With the increasing depletion of fossil energy and the increasingly severe environmental problems,as well as the concept of sustainable development,it is imperative to develop clean and renewable new energy.Electrolytic water hydrogen production technology can realize the conversion of electric energy and Hydrogen energy,which is clean and pollution-free.It is considered to be a technology with great development potential and value.The selection of catalyst is the key to improve the conversion of hydrogen production from electrolyzed water.At present,platinum group noble metals are considered to be the best catalytic materials in the field of hydrogen evolution catalysis,but their expensive price and scarce resources limit their large-scale application.Therefore,it is very important to develop high efficiency and low cost catalysts for hydrogen evolution.In this paper,Ni-P/NF,Ni-P-CAPT/NF and Ni-P-Mo/NF series catalytic hydrogen evolution electrodes were prepared by electrodeposition.The structure of the electrodes was characterized by SEM,EDX and XRD.The hydrogen evolution performance of the electrodes was studied and the hydrogen evolution mechanism was discussed.The main results are as follows:1.Ni-P/NF porous electrode:the effects of CV cycle times,the highest deposition potential and the proportion of Ni-P reactant on the hydrogen evolution activity of Ni-P/NF catalytic electrode were studied.The optimal deposition conditions of Ni-P/NF electrode were obtained:CV cycle times 80 times,the highest deposition potential 1.0~1.2V,Ni/P=1/4.The hydrogen evolution performance of Ni-P/NF electrode on foamed nickel has been significantly improved.When the current density is-10mA/cm~2,the alkaline and acid Overpotentials are 103mV and124mV respectively.2.Ni-P-CAPT/NF electrode:Through adding complexing agent sodium citrate and buffer boric acid to optimize the electrodeposition solution,and studied the effect of different adding amount in Electrodeposition solution on the hydrogen evolution performance of the electrode.The results show when the adding amount of sodium citrate and boric acid is 0.8mol/l and 0.4mol/l respectively,the hydrogen evolution performance of Ni-P-CAPT/NF electrode is the best.When the current density is-10mA/cm~2,the hydrogen overpotential of Ni-P-CAPT/NF electrode is87mV and 100mV respectively under alkaline and acid conditions,and it has good hydrogen evolution stability.3.Ni-P-Mo/NF electrode:By adding sodium molybdate to the electrodeposition solution,the transition metal Mo was introduced,and the Mo doped Ni-P-Mo/NF electrode was prepared.The effect of the highest deposition potential and the content of sodium molybdate in the electrodeposition solution on the hydrogen evolution performance of Ni-P-Mo/NF electrode was studied.The results show that the highest deposition potential is 1.4V and the amount of sodium molybdate is 0.08mol/l obtains the best performance.The current density of Ni-P-Mo/NF electrode is-10mA/cm~2 while the over potential is only 70mV in alkaline condition,and only92mV when the current density is-10mA/cm~2 in acid condition.4.By comparing the characterization of foam nickel,Ni-P/NF,Ni-P-CAPT/NF,Ni-P-Mo/NF electrode SEM,EDX and XRD,combined with electrochemical characterization,the reason and mechanism of hydrogen evolution performance of electrode were discussed.Thin films were deposited on the surface of Ni-P/NF,Ni-P-CAPT/NF and Ni-P-Mo/NF electrodes by electrodeposition and they are amorphous structure,and their catalytic hydrogen evolution performance is better than that of pure nickel.The addition of sodium citrate and boric acid improved the quality of the film on the surface of Ni-P-CAPT/NF electrode and the interface between the film and the substrate.Molybdenum doping increases the roughness of the film on the surface of Ni-P-Mo/NF electrode,increases the reaction area of hydrogen evolution,what's more,the doping of molybdenum also reduces the charge transfer resistance between the electrode and the electrolyte,and increases the charge transfer rate of the electrode.