Alkali-assisted, atmospheric plasma production of Titania nanowire powders and arrays

We report a new ultrafast (reaction time on the scale of a minute) gas-phase method for synthesizing highly crystalline titanate phase nanowires (NWs) using oxidation of either Ti metal (foils or powders) or spherical TiO₂ powders with an atmospheric pressure microwave plasma. In this method, alkali metal compounds of Li, Na, and K are shown to form molten alloys of alkali metal-Ti-O during plasma exposure. Bulk nucleation and subsequent basal growth of the resulting nuclei from the molten alkali metal-Ti-O resulted in the respective titanate NWs. The current state-of-the-art methods involve long reaction time scales (∼1 day) for synthesis of TiO₂ NWs.