  Nanoporous metals possess unique properties attributed to their high surface
area and interconnected nanoscale ligaments. They are mostly fabricated by wet
synthetic methods involving solution-based dealloying processes whose purity is
compromised by residual amounts of the less noble metal. Here, we demonstrate a
novel dry synthesis method to produce nanoporous metals, which is based on the
plasma treatment of metal nanoparticles formed by physical vapor deposition.
Our approach is general and can be applied to many metals including non-noble
ones. The resultant nanoporous metallic films are impurity-free and possess
highly curved ligaments and nanopores. The metal films are remarkably robust
with many catalytically active sites, which is highly promising for
electrocatalytic applications.
