Preparation of copper foam with 3-dimensionally interconnected spherical pore network by electrodeposition

A highly porous copper foam with 3-dimensionally interconnected pores was made by an electrodeposition technique utilizing hydrogen bubbles, generated concurrently with copper deposition, as templates for forming spherical pores. Chemical additives such as NH4+, Cl−, polyethylene glycol (PEG), and 3-mercapto-1-propane sulfonic acid (MPSA) were introduced into Cu electrodeposition bath, and their effects on the porosity and strength of the copper foam were examined at an extremely high cathodic polarization. NH4+ significantly suppressed both copper electrodeposition and hydrogen evolution by its adsorption on cathode surface. The additives, such as Cl−, PEG, and MPSA, usually used at relatively low current density were found to be also effective even at extremely high polarization. In particular, MPSA played a key role in the formation of the foam structure with 3-dimensionally interconnected pores as well as smooth and strong foam wall. Apparent density of the resulting copper foam foil was as low as 0.2 g cm−3.