Improving the chemical de-alloying of amorphous Au alloys

In this work, the chemical de-alloying behavior of Au30Cu35Ag7Pd3Si20(at.%) amorphous alloy which was rapidly solidified from the melt in the form of ribbons were investigated. First a comparison between samples de alloyed in nitric acid with and without HF was conducted to achieve homogeneous de-alloying process. Then the morphology and structure of nanoporous gold (NPG) were adjusted by tuning the de-alloying parameters, such as HNO3 concentration, electrolyte temperature and de-alloying time. Finally the surface enhanced Raman scattering(SERS) capability of the as-prepared NPG was evaluated using 4,4'-bi-pyridine as probe molecule.