Nanoporous metals by dealloying multicomponent metallic glasses

The synthesis of nanoporous palladium by electrochemically dealloying multicomponent Pd₃₀Ni₅₀P₂₀ ribbons were produced by single-roller melt-spinning in vacuum which was introduced in detail elsewhere. X-ray diffraction (XRD) and transmission electron microscopy (TEM) demonstrated that the as-obtained ribbons are fully amorphous with a uniform structure and composition down to subnanoscale. The electrochemical dealloying process of the Pd₃₀Ni₅₀P₂₀ metallic glass was monitored by the cross-sectional SEM micrographs. Nanoporous palladium with a rather uniform structure was obtained. It was observed that nanoporosity formation is mainly controlled by the dissolution process of the less noble Ni and P in the metallic glass system rather than by the surface diffusion of Pd in the acid during electrochemical dealloying.