Fabricating The Hydrogen Evolution Material Of Non-noble Metal Sulfide Loaded On The Treated Metal Foam By Plasma And Its Properties Characterizaiton

Hydrogen energy is a kind of clean renewable energy which has many prominent merits such as rich in resources and easy to store up.Because of the exhaustion of the fossil fuels and the environmental crisis,people have paid more attention to it.The main method to prepare hydrogen on a large scale is water electrolysis.In order to decrease cathode overpotential for reducing energy consumption,it's of momentous significance to research new cathode eleetrode materials which have lower hydrogen-evolution overpotential and high catalytic activity.Two methods are used to prepare cathode materials with high catalytic activity for hydrogen evolution.One is to search for a new kind of catalytic materials with a high catalytic activity so as to improve the electrocatalytic activity.The other is to increase the actual specific surface area of the electrode,namely to amplify the electrode surface roughness for decreasing the true current density of the electrode surface in the course of electrolysis reaction,so as to reduce the cathode overpotential.Foam nickel?NF?is a commercial metal material with three-dimensional openings,porosity and metal skeleton interconnection.It is widely used in Ni-MH battery electrode materials,fuel cells and other fields.These materials have a large electrochemical reaction interface,and it shows potential application in the field of electrochemical hydrogen evolution.In this paper,the foam nickel?NF?substrate was pretreated by DBD plasma,and many micro/nanosized cracks occurred on the NF frames which was very useful for fabricating high density of chalcogenides.The SEM results show the electrode material of PNF/Ni₃S₂ was prepared by combining plasma technology and hydrothermal method.When the NF was treated by DBD plasma for 10 min,the hexagonal crystal plates of Ni₃S₂ were formed on the NF surface and exhibited regular flower morphology with a longer reacting time.The average diameter of the Ni₃S₂ flowers was about 2 um,and the thickness of each crstal plate was about 25 nm.The results of electrocatalytic hydrogen evolution in alkaline solution show that the PNF/Ni₃S₂ with flower structure presented excellent electrocatalytic activity and stability,and the initial overpotential was about-0.10 V?vs RHE?,and the overpotential with a current density of 100 mA cm-2 was-0.439 V?vs RHE?.The 12-hour time-current?I-t?curve was a horizontal line,and the polarization curves after 10000 CV cycles changed gently.The phenomenon indicated that the PNF/Ni₃S₂ catalyst was very stable in the electrochemical process.Meanwhile,the CdS quantum dots were dotted on the Ni₃S₂ surface in order to increase its electrocatalytic activity.From the morphological characterization,the nano-sized CdS particles were homogeneously loaded on the flower-like Ni₃S₂ surface.Compared to the PNF/Ni₃S₂,the hydrogen evolution results of PNF/Ni₃S₂/CdS show that the required overpotential at a current density of 100 mA cm-2 was reduced from-0.439 V?vs RHE?to-0.399 V?vs RHE?,and the slope of the tafel curve was reduced from 0.305 V decade-1 to 0.272 V decade-1.Moreover,no change occurred for the curve of time-current?I-t?at 12 h and the polarization curves after 10000 CV cycles,Indicating that CdS nanoparticles did not fall off in the electrochemical reaction.The hydrogen evolution performance of PNF/Ni₃S₂ dotted with CdS nanoparticles increased greatly,and it may be a promising protocol for fabricating electrode materials with high electrocatalytic activity.