Cupric oxide (CuO) nanowires were produced by the thermal oxidation of copper surfaces at temperatures up to 450 °C. Three different surfaces, namely a copper foil, evaporation-deposited copper, and an application-relevant sputtered copper film on Si(100) substrates, were characterized ex-situ before and after the experiment. The development of oxide layers and nanowires was monitored in situ using grazing incidence small angle X-ray scattering. The number density of nanowires is highest for the sputtered surface and lowest for the surface prepared by evaporation deposition. This can be linked to different oxide grain sizes and copper grain boundary diffusions on the different surfaces. Small grains of the copper substrate and high surface roughness lead to promoted nanowires' growth. In recent years, metal oxide nanostructures have neem investigated for various applications, such as sensors, energy-efficient coatings, and semiconductor devices. Copper oxide nanowires have attracted considerable interest during the last couple of years. This is partly caused by the semiconductive properties of CuO having a bandgap of 1.85 eV6. The nanowires' large surface is advantageous for many applications such as solar cells, catalysis, or sensor applications. Copper oxide nanowires can be grown by a wide variety of techniques. The simplest procedure might be to grow them by heating a copper surface in an oxygen-containing atmosphere.
The nanowires form on the surface at temperatures ranging from 300 °C to 700 °C. Typically, higher temperatures lead to an increase in diameter, while longer growing times lead to an increase in aspect ratio. However, the crystal size of Cu and its oxides is of great importance for the growth of the nanowires, which can form on top of CuO crystallites. To grow, copper atoms must migrate through the two oxide films and up the nanowires. Grain boundary diffusion is considered the dominating contribution to this mass flow, followed by surface diffusion once the surface between the CuO grains has been reached. Consequently, a larger number of grain boundaries leads to increased diffusion and, therefore, to better growth of the nanowires. If you are looking for high quality, high purity, and cost-effective Copper oxide, or if you require the latest price, please email contact mis-asia.
