Recent Progress in the Study of Molecularly Doped Metals

A unique materials' methodology enables the doping of metals with functional molecules, polymers, enzymes, and nanoparticles. The resulting materials have either the combined properties of the metal and the dopants, or new, sometimes synergetic properties that are not found in the separate components, emerge. Metals that have been doped so far include gold, silver, copper, iron, gallium, palladium, platinum, and several alloys. Numerous applications have been demonstrated including catalysis, biocatalysis, bioactivity, electrochemistry (including new type of batteries), corrosion resistance, induction of chirality, tailoring unconventional properties to metals, and more. Doping of metals and adsorption on them are completely different processes, doping being a 3D event, while adsorption is a 2D process. Thus, practically all special properties and functionalities that have been demonstrated are apparent only in the doped case. Here, progress made in this field in the past four years is reviewed, including methodologies for obtaining metallic doped thin films, enhancing corrosion resistance, biomedical applications, and the use of doped metals for complex catalytic network of reactions. A materials methodology is described, which enables molecular doping of metals. It is shown that the resulting modified metals have properties that are either a combination of the metal characteristics and the functionality of the dopant, or that display altered or synergistic properties of the components. Thin doped metallic films, new catalysts, and new biomaterials are described.