Study On Preparation And Electrochemical Properties Of Porous Bimetal Material

Porous material has large specific surface area which can provide large amount of active site for catalyst and adsorption.Thus porous material has a wide application in the field of catalyst,clean and etc.Hydrogen evolution assisted electrodeposition is one of the most effective methods to prepared micro-nano porous metals.This work focuses on the development of porous metallic catalysts using hydrogen evolution assisted electrodeposition.Firstly,copper dendrites with three dimensional pores were prepared by hydrogen evolution assisted electrodeposition.The effects of the additives,deposition time and current density on the morphology and structure of the copper dendrites were investigated.By adding different additives into deposition solution(0.2M CuSO4+IM H2SO4),copper with different micro-morphologies including corncob-like dendrite(none),grape-like dendrites(BTA)and branch-like dendrites(KCl+K2SO4+NH4Cl)were prepared.All samples show 3-dimensional porous structure except the grape-like copper.The deposition time play an important role on the thickness of the as-deposited copper.However the morphologies of the dendrites and pores in this study show no significant changes.When the porous copper is used as a catalyst for the degradation of the direct blue 15(DB15),it shows great catalytic activity.Moreover,the impacts of morphology and addition of the porous copper,degration temperature,PH of the solution,concentration of H2O2 and concentration of DB15 on the degradation efficiency were investigated.Secondly,micro-nano porous gold was prepared by hydrogen evolution assisted electrodeposition.The effects of the deposition time and temperature on the morphology and catalystic activity of the porous gold was investigated.With the increase of the deposition time and temperature,the deposition layer became thicker,and the walls of the pores became denser.The density of dendrites increased at the same time.All the as-deposited gold samples display catalytic activity toward the oxidation of glucose.The sample deposited at 25? for 300s showed the best catalytic activity,as evidenced from the low glucose oxidation potential at 0.405V(vs Ag/AgCl).Finally,hydrogen evolution assisted electrodeposition combined with wet-chemical method was used to prepare Au-Cu bi-metal catalyst towards the oxidation of glucose.The influence of replacement time,reaction solution and morphology of template on the morphology,composition and catalytic activity of Au-Cu bi-metal catalyst were investigated."The porous structure of the as-deposited samples collapsed after a replacement reaction between Cu and Au.Though the increase of the replacement led to the deterioration of the porous and dendritic structure,the content of gold increased.In alkaline solution,the sample replaced for 5 minutes showed the best catalytic activity toward glucose oxidation.The addition of ethylene glycol into the replacement solution could inhibit the replacement reaction and delay the structure deterioration.However,in pure ethylene solution,the replacement reaction was too slow to load enough gold.Therefore the sample replaced in the mixed solution of water and ethylene glycol exhibited the highest catalytic activity towards the glucose oxidation when compared with the samples replaced in water or ethylene solution.The corncob,graph-like copper samples after the replacement in water + ethylene showed structure deterioration,while the branch-like copper after replacement exhibited the best catalytic activity toward glucose oxidation.