Synthesis of well-ordered CuO nanofibers by a self-catalytic growth mechanism

One-dimensional and well-ordered CuO nanofiber arrays have been synthesized by a processing of self-catalytic growth. Using polycarbonate (PC) membrane as a template, copper nuclei sites Cu(111) were uniformly deposited on copper substrate via a high voltage input (electric field: 15 V/cm) in a copper sulphate solution. According to the pore diameter of PC membranes, two different sizes of copper nuclei could be well-controlled in ranges of 50 to 60 and 100 to 150 nm. With heat treatment in oxygen atmosphere, the electrodeposited copper nuclei were transformed into CuO nanofiber arrays. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analyses showed that the nanocrystalline CuO nanofibers with a mean length of 8 μm had an average order of ${10}^7{\text{–10}}^8/{\mathrm{cm}}^2$ in density, and their average diameters were accorded with the size of Cu nuclei.