Formation and control of nanoporous Ag through electrochemical dealloying of the melt-spun Cu-Ag-Ce alloys

In this work, the ultrafine nanoporous Ag ribbons were achieved through addition of 2 at.%-6 at.% Ce into the melt-spun Cu-Ag alloys and applying different electrochemical dealloying potentials. The dendritic morphology of the ligaments in the dealloyed Cu ₈₀Ag ₂₀ alloy varied to be equiaxial due to the addition of Ce, and the pore size reduced from 200 nm to less than 60 nm. The nanoporous Ag with an average pore size of ∼15 nm was obtained from the Cu ₇₄Ag ₂₀Ce ₆ alloy. The pore and ligament sizes of the nanoporous Ag prepared from the Cu ₇₆Ag ₂₀Ce ₄ alloy exhibited an increasing tendency with the increase of applied potentials, while the dealloyed Cu ₇₈Ag ₂0Ce ₂ had an opposite variation. Moreover, the addition of Ce into the Cu-Ag alloys also promoted the dealloying. Nanoporous Ag exhibited the stronger enhancement of the surface enhanced Raman scattering effects with the increase of Ce contents in the precursory alloys.