Nanoporous Gold Foams with Tunable Porosity Fabricated by Chemical Dealloying

S. Niauzorau, A. Sharstniou, M. Gregory, B. Azeredo
Arizona State University,
United States

Keywords: nanoporous gold, dealloying, porosity, volume fraction


Recently, porous materials and, particularly, porous metal powders and foams fabricated by various techniques, such as dealloying, electrochemical and electroless deposition, templating, sputtering, have drawn a growing interest as they can be implemented in fields such as energy storage, chemical catalysis, bio- and chemical sensing, and medicine. Moreover, nanoporous metal thin-films and foams exhibit unique properties that vary from bulk material properties. In this paper, we show a study on the porosity dependence of dealloyed gold-silver films fabricated by chemical dealloying in the varying acid concentration and etching time. By controlling the acid concentration, it was possible to tune the nanoporous silver-gold morphology from partially to a completely dealloyed films with pore sizes from 5 to 40 nm. The capability of tuning the dealloying conditions gives a high level of control of the porous gold morphology (size of pores and pore volume fraction).