Influence of Ni or Pt addition on dealloying behavior of Al2Au-based precursors in a NaOH aqueous solution

The influence of Ni or Pt addition on dealloying behavior of Al2Au-based precursors has been investigated considering the formation of nanoporous structure, surface diffusion of Au and activation energy. The results show that ultrafine nanoporous AuNi and AuPt alloys can be fabricated by dealloying Al66Au27.2Ni6.8 and Al66Au27.2Pt6.8 precursors in a NaOH solution. The addition of Ni or Pt can significantly retard surface diffusion of Au, and surface diffusivities of Au range from ∼10−24 to ∼10−21 m2 s−1 depending upon the dealloying temperature. Additionally, the activation energy has been evaluated for the dealloying of Al66Au27.2Ni6.8 and Al66Au27.2Pt6.8.