Needle-shaped nanocrystalline CuO prepared by liquid hydrolysis of Cu(OAc)2

Needle-shaped copper oxide (CuO) nanocrystals have been successfully prepared by hydrolysis of copper acetate (Cu(OAc)2) solution. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–vis absorption spectroscopy. The results show that the diameters of the needle-shaped CuO nanocrystals can be controlled between 10 and 45 nm simply by varying the concentration of Cu(OAc)2 solution, the presence of small amounts of cetyltrimethylammonium bromide (CTAB) can render needle-shaped CuO well dispersed. The band gap is estimated to be 2.78 eV according the results of the optical measurements of the CuO nanocrystals.