Preparation Of Nickel-phosphorus Composite Electrode And Its Electrocatalytic Activity For Hydrogen Evolution

Nowadays,with the development of industrial processes and the improvement of people's quality of life,our demand for energy is increasing day by day.At the same time,the environmental pollution problems accompanying the use of stone fuels have caused people's living environment to deteriorate.The situation of energy shortage and environmental pollution has become more and more serious.Clean and renewable energy development is an urgent task.With the advantages of abundant resources,high calorific value,and environmental protection,hydrogen has been considered to be an ideal substitute for fossil energy.Among the many existing hydrogen production methods,hydrogen produced by electrolyzed water has the advantages of safety and sustainability,and has great potential for development.However,the high hydrogen evolution overpotential on the cathode hinders the further industrialization process.Therefore,the development of electrode materials with high hydrogen evolution activity to reduce the hydrogen evolution overpotential has become a research hotspot for researchers.The nickel-based hydrogen evolution electrode prepared by ultra-gravity electrodeposition has superior catalytic activity,but the surface structure of the electrode is relatively dense.The addition of nano-carbon materials can increase the nucleation rate of nickel,effectively inhibit the growth of nickel particles,increase the specific surface area of the electrode,and increase the number of active sites in the catalytic reaction,which is an important way to improve the electrode activity.The research content of this paper is as follows:Ni-P electrodes were prepared by super-gravity electrodeposition on the basis of copper foil and its electrocatalytic hydrogen evolution performance was studied.This chapter explores the effect of sodium hypophosphite on the properties of the coating.The experimental results show that the addition of phosphorus greatly enhances the catalytic performance of the coating.When the concentration of sodium hypophosphite in the plating solution is 0.3M,the best performance of Ni-P₃ is obtained,and the overpotential required for current density of 100 mAcm^-2 is 208 mV;The Tafel slope is 65 mV dec^-1;The transfer impedance is 1.742?.This is because the introduction of phosphorus inhibits the growth of nickel crystal grains,serves the purpose of refining crystal grains,and also increases the lattice chaos and improves the roughness of the electrodes.However,the Ni-P coating is relatively flat and compact,with a small specific surface area and a shape to be improved.The graphite oxide is prepared by the modified hummers method and co-deposited as a composite phase with nickel and phosphorus to enhance the specific surface area and catalytic performance of the coating.In this chapter,the influence of deposition current density on the composite coating was investigated at a concentration of 1 g/L of graphite oxide.When the deposition current density is 30 mA cm^-2,the composite coating NiP/rGO₃₀ with uniform morphology and best performance is prepared.When it reaches a current density of 100 mA cm^-2,the required overpotential is 165 mV,the Tafel slope is 39mV dec^-1,and the transfer impedance is 1.878?.Moderate current density is the key to making a good crystalline coating.Besides,the reduced graphite oxide provides a large deposition area for the deposition of nickel and also increases the specific surface area of the coating.Through the ball milling and activation treatment,the purpose of shortening the carbon nanotubes and increasing the water solubility thereof is achieved.In this chapter,nickel-phosphorus carbon nanotube composite coatings were prepared by using carbon nanotubes as the composite phase.This chapter mainly explores the effect of carbon nanotube content on the performance of composite coatings.When the content of carbon nanotubes in the plating solution is 2g/L,the prepared coating NP-CNT₂ has the best performance.When the current density is 100 mA cm^-2,the required overpotential is 173mV,the Tafel slope is 114 mV dec^-1,and the transfer impedance is 1.253?.The addition of carbon nanotubes enhances the conductivity of the coating,refines the nickel particles,and increases the catalytic performance of the composite coating.In addition,the nickel-phosphorus carbon nanotube composite electrode exhibits excellent cycle stability after a long period of hydrogen evolution reaction.