| With the development of the world economy,there is also an increasing demand for energy.As the main energy source used in various countries,the reserves of fossil fuels are increasingly decreasing.With the using of the fossil fuels,a large number of sulfide,carbide and other harmful gases lead to the deterioration of the earth's environment,such as acid rain,haze and global warming.Therefore,many countries have been beginning to seek all kinds of new energy to replace fossil energy.Attribute to the excellent characteristics of hydrogen,hydrogen is considered the most promising new energy now.At present,the widely used electrolytic water hydrogen production has high electrode preparation cost and low corrosion resistance and low electrode hydrogen production efficiency.Compared to non-precious metals,Pt is considered a high-efficiency electrocatalyst.Also,Pt belongs to rare and precious metals,it limits its application in the market field.Ni foam(NF)is a mesh structure material with good electrical conductivity and large specific surface area.And its immature electronic structure is conducive to the adsorption and desorption of hydrogen and has great potential in the preparation of hydrogen precipitation electrodes and is usually used as an electrocatalyst substrate in the field of electrocatalysis.Ni-P/NF electrodes were deposited on nickel foam substrate by constant voltage electrodeposition,which are Ni-P/NF-0.25,Ni-P/NF-0.5,Ni-P/NF-1,Ni-P/NF-1.5,Ni-P/NF-2.Studies show that the Ni-P/NF-0.5 hydrogen electrocatalyst is the best electrode,in 1mol/L KOH electrolyte solution,with an overpotential of 100 m A/cm~2 and Tafel slope is 93.3m V/dec,the corresponding charge transfer resistance is 7.1?and the Ni-P/NF-0.5 electrode can reach a maximum current density of 210 m A/cm~2 at an overpotential of 310 m V.In the multi-step voltage test,the Ni-P/NF-0.5 electrode also showed excellent stability energy.According to the analysis,the appropriate amount of phosphorus content made the hydrogen precipitation tissue with nickel and phosphorus evenly distributed when the Ni-P/NF amorphous electrode was formed.Ni-P/Ni S2/NF was prepared from Ni-P/NF.Comparing to AT-NF(Acid Treated Ni Foam)and Ni-P/NF.At current density of 100 m A/cm~2,Ni-P/Ni S2/NF can reach 224 m V,20%lower compared to Ni-P/NF electrodes,a Tafel slope of 89 m V/dec,charge transfer resistance of 2?and double layer capacitor of 23.8 m F/cm~2.In the sulfated Ni-P/NF electrode,P and O in part of the Ni-P amorphous tissue and Ni-O compounds were replaced by S elements,forming Ni S2,which further improved the electrocatalytic hydrogen precipitation performance.Ni S/Ni S2/NF hydrogen precipitation electrodes were prepared on the surface of nickel foam by two-step methods of hydrothermal and vulcanization,and Ni S/Ni S2-8,Ni S/Ni S2-4,Ni S/Ni S2-2,and Ni S/Ni S2-1 were prepared by varying the doping amount of S.We show that the electrocatalytic activity of the Ni S/Ni S2-4 electrode is optimal.When the current density of 100 m A/cm~2,The overpotentials of Ni S/Ni S2-8,Ni S/Ni S2-4,Ni S/Ni S2-2,and Ni S/Ni S2-1were 302 m V,202 m V,244 m V,and 372 m V,respectively,For the Ni S/Ni S2-4 electrodes,at a current density of 250 m A/cm~2,Its overpotential is 245 m V,The Ni S/Ni S2-4 electrode Tafel slope was 69 m V/dec,Charge-transfer resistance is 1.8?,The double-layer capacitance is31.6 m F/cm~2,According to the analysis,Under a certain amount of sulfur element doping,The performance of Ni S/Ni S2 hydrogen precipitation electrode prepared by sulfide reaction was better improved. |
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