Well-aligned CuO nanowires detached from Cu foil by a simple contact printing method

We report the growth of CuO nanowires from copper foils oxidized in air at temperatures between 400 and 800 \(^{\circ }\hbox {C}\). The synthesized nanowires have two different morphologies, straight and bent, with diameters of 50–400 nm and lengths of 1–55 \(\upmu \hbox {m}\). Here, we demonstrate, highly dense, regular arrays of nanowires with high uniformity and few composite particles of CuO and \(\hbox {Cu}_{2}\hbox {O}\) by a simple contact printing process, in assistant with the viscosity and lubrication of the silicone oil. The average length of nanowires is approximately 15 \(\upmu \hbox {m}\) and the longest NW’s length is around 55 \(\upmu \hbox {m}\). The distribution is uniform, basically in a direction and the density is very large. The nanowires are rarely damaged. Compare to the conventional way, the contact printing used in this paper is an easy, efficient method of the nanowires transferred from one substrate to another substrate and significantly reduced the experiment cost of the nanowire transfer.