Inorganic Nanomaterials Synthesis Using Alkalide Reduction

Chemical (solution) methods of nanomaterial synthesis offer the advantages of simplicity, stoichiometric control, ease of scale-up, and the possibilities of size control and narrow size distributions. Of the many solution methods of making nanoparticles, the reduction of metal salts by alkalides or electrides, generally referred to as alkalide reduction, is particularly promising due to its ability to protect highly oxyphilic elements and its use of the most power reductants possible in any given solvent. This makes it general across the periodic table including the early transition metals and rare earth elements. In fact, to date, it is the only solution method shown to be capable of synthesizing lanthanide metal nanoparticles. Binary and higher order phase nanomaterials are also possible by the simultaneous alkalide reduction of multiple elements. Nanoscale oxides and nitrides can be formed by reacting nanomaterials made by alkalide reduction with the appropriate gas. Spheroidal nanoparticles as small as ∼1 nm in diameter can be synthesized by this method as can rods up to ∼1 µm in length. The current practice and capabilities of highly versatile synthetic routes to nanomaterials are outlined in this article. Keywords: alkalide; electride; nano; magnetic; phosphor; alloy; carbide; oxide; nitride; rod