Formation and microstructure of nanoporous silver by dealloying rapidly solidified Zn–Ag alloys

The electrochemical dealloying of rapidly solidified (RS) Zn–Ag alloys in a 5 wt.% HCl solution and 1 M NaCl solution has been investigated using electrochemical measurements and microstructural analysis. The results show that the electrochemical properties of the RS Zn–Ag alloys are associated not only with the alloy composition, but with the phase constitution of the alloys. Nanoporous silver (NPS) ribbons can be fabricated through potentiostatically dealloying the RS Zn–Ag alloys in both solutions. Moreover, a minor difference in the applied potential has a significant influence on the dealloying process and formation of NPS. The critical potential and polarization behavior of the Zn–Ag alloys have also been discussed, as well as surface diffusion of Ag adatoms.

► Nanoporous silver can be fabricated by electrochemical dealloying of Zn–Ag alloys.
► Phase constitution markedly affects electrochemical activities of Zn–Ag alloys.
► Formation of nanoporous silver is sensitive to the change of applied potentials.