Facile and scaleable transformation of Cu nanoparticles into high aspect ratio Cu oxide nanowires in methanol

In this work, a facile synthetic route for the preparation of high aspect ratio Cu oxide nanowires is reported. The preparation of the Cu oxide nanowires begins with the generation of pure Cu nanoparticles by inert gas condensation (IGC) method, follows by dispersing the obtained nanoparticles in methanol with the aid of ultrasonication. The mixture is stored at different temperature for the transformation from Cu nanoparticle to Cu oxide nanowires. The influences of the kind of solution, the ratio of methanol to Cu nanoparticle, dispersion time and temperature towards the generation of Cu oxide nanowires are studied in detail. Scanning electron microscopy studies indicate that high aspect ratio Cu oxide nanowires with diameter of a few tens of nanometers and length up to several tens of micrometers could be obtained under proper conditions. The mechanism for the transformation of Cu nanoparticles to Cu oxide nanowires is also investigated.