Temperature and time dependent morphological evolution of solution phase synthesized copper oxide nanostructures

Copper oxide (CuO) is an important transition metal oxide used in a wide variety of applications, such as gas sensors, magnetic storage media, lithium-ion electrodes, electronic device fabrication etc. CuO nanostructures (NS) exhibit exclusive properties considerably different from their bulk counterparts, such as highly reactive surfaces, different optical, electrical and catalytic properties which strongly depend on the shape, size and crystal structure of the NS. By altering the aspect ratio (length to diameter ratio) and shape of CuO NS, physical and chemical properties of these NS can be tailored. In this work, an array of CuO NS was synthesized on thin copper foil substrate through wet chemical route at different temperatures and times, followed by a thermal reduction in an Ar/H₂ atmosphere. Cu foil itself was polished to different roughness levels and deformed to different thickness levels, prior to the reaction, to induce different growth conditions leading to the formation of CuO NS of different morphologies. The present study shows simple, scalable technique to synthesize various CuO NS that can be helpful in future to ameliorate various physical and chemical properties of CuO.