Synthesis of Large-Scale Cadmium Oxide Nanowires from an Aqueous Solution

We report on a simple and template-less technique for growing ultra-long cadmium oxide nanowires on an indium tin oxide (ITO) surface from the aqueous solution. The nanowires, free-standing and with various diameters, are realized on the ITO surface by following a simple hydrothermal reaction of cadmium nitrate and hexamethylenetetramine of a similar molar ratio at 120°C. The nanowires have diameters in the range of 10 to 30 nm and lengths of up to a few tens of micrometers. We identified that the concentration of the solution precursors is crucial to the growth density of the nanowires on the surface but less important to the structural growth (length and geometry) of the nanowires. Such nanowires might possess unique properties that can be used for prospective photonics and optoelectronics materials.