Preparation Of Hierarchical Porous Coppers And Thier Electrocatalyic And Mechanical Properties

Nanoporous metal material has good conductivity and permeability,and the pore structure is easy to control,so it is suitable to be used as electrode material in electrocatalytic reaction.Compared with other precious metals which have been widely studied,the raw materials of porous copper is easy to get and the cost is relatively low.By introducing two-scale micropores,the seepage action of nanoporous copper can be significantly improved,and it is easy to prepare bulk hierarchical porous copper.In this paper,with NaCl as the space holder and Cu-Mn solid solution alloy as the precursor,hierarchical porous copper with two-scale micropores and onescale nanopores was prepared by adding space holder powder metallurgy and dealloying.Using X-ray diffraction,scanning electron microscope and other research methods to explore the influence of different preparation parameters on the microscopic morphology of hierarchical porous copper,and through the cyclic voltammetry test and compression test to explore the influence of different preparation parameters on the electrocatalytic properties and mechanical properties.The main research results are as follows:As the content of Mn increases,the pore size of the first-scale micropores increase and the pore size of the third-scale nanopores decrease,and the porosity of the porous copper prepared by the precursor Cu40Mn60 is larger than that prepared by Cu50Mn50.When the diameter of NaCl decreases from 100-120 mesh to 160-200 mesh,the pore size and porosity of the first-scale micropores both decrease.The forming pressure can obviously affect the micropores structure.The pore structure is not perfect and the distribution is not uniform when the forming pressure is less than 2MPa,the pores are gradually formed and densified with the increases of the pressure.The sintering time mainly affects the pore sizes of the first and second-scale micropores.With the extension of the sintering time,the average pore sizes of the first-scale micropores increase,while the pore sizes of the second-scale micropores decrease obviously.The hierarchical porous copper exhibits certain electrocatalytic properties for methanol and glucose in NaOH solution,and the hierarchical porous copper obtained by dealloying the precursor Cu40Mn60 is superior to Cu50Mn50 for methanol and glucose.After 10 cycles of cyclic scanning,it was found that the oxidation peak current density value decreases very little and has good stability.When the methanol concentration increases from 0.25mol/L to lmol/L,the oxidation peak current density gradually increases,and when the methanol concentration increases to 1.25mol/L,the oxidation peak current density shows a downward trend,that is,lmol/L is the best methanol catalytic concentration.The hierarchical porous copper in H2SO4 solution exhibits higher electrocatalytic activity for methanol as the concentration of H2SO4 rises,however,in the high concentration H2SO4 electrolyte solution,self-corrosion is also more serious.The compressive stress-strain curve of hierarchical porous copper consists of three regions:elastic deformation region,yield platform region and densification region.The elastic modulus and yield strength of hierarchical porous copper prepared from precursor Cu50Mn50 were higher than that of Cu40Mn60.The elastic modulus and yield strength of hierarchical porous copper decreases with the increases of the space holder content.With the extension of sintering time,the elastic modulus and yield strength of hierarchical porous copper increases simultaneously.