Structural Synthesis And Design Of Hybrid Nickel-based Materials And Their Applications In Electrochemistr

Under the severe challenge of depleting resources and the dual threat of non-renewability of fossil fuels in the present era,people are urgently seeking a new clean,environmentally friendly and renewable energy source as a solution to the current energy crisis,and the electrolysis of water to produce hydrogen has therefore received much attention.The hydrogen evolution reaction of noble metals,such as Pt,Pd and their alloys,is considered to be the most effective hydrogen evolution reaction at present,but these metals are rare and expensive.However,MoS₂ has some shortcomings of its own,such as poor electrical conductivity and easy to agglomerate during the formation process and obscure the active sites.Therefore,in this thesis,in order to overcome the above-mentioned shortcomings of MoS₂,nickel-based materials are used as substrates,which enhance the electrical conductivity of the materials and also reduce the agglomeration of MoS₂.At a time when the demand for sustainable energy is increasing,new devices to improve the performance of energy storage and conversion devices are attracting interest and gaining significant attention.This has brought supercapacitors into the limelight,which are considered by researchers as excellent candidates for rechargeable energy storage devices,and hybrid supercapacitors are considered as an effective solution to the low energy density problem,while electrode materials are the key to determine the performance of supercapacitors.In this thesis,nickel-based materials were chosen to be compounded with carbon nanotubes to retain the high capacity of the nickel-based materials themselves,while improving their electrical conductivity and porosity through carbon nanotubes.In this thesis,both hydrogen precipitation performance and capacitive performance are investigated by different structural designs of heterogeneous nickel-based materials.The main contents include.（1）ZnO and MoS₂ were synthesized successively on nickel foam substrates by a one-step hydrothermal method,and ZnO was used to regulate the growth structure of MoS₂/NiS,and then the obtained ZnO-MoS₂/NiS composites were immersed in acidic solution to remove ZnO to obtain the final products.The structure of the material was regulated by controlling the amount of ZnO,and the best hydrogen precipitation performance was achieved when the addition of ZnO was 1.5 mmol,i.e.,the overpotential was only 156 mV at a current density of 10 mA cm^-2,which showed excellent catalytic performance.（2）Nitrogen-doped carbon nanotubes derived from polypyrrole hollow tubes were used as the backbone for the simultaneous phosphorylation and carbonization to prepare Ni₂P/NCHTs materials.Carbon nanotubes are beneficial to accelerate the electron and ion transport due to their properties of both carbon materials and hollow structures,and the doping of nitrogen atoms in carbon nanotubes ensures the higher electron affinity and the number of active sites of the catalytic materials.the NCHTs complement each other with Ni₂P,which not only has a high specific surface area,but also improves the conductivity and electrochemical properties in 2M KOH at 1A g^-1 conditions obtained a significant specific capacitance.