Synthesis and characterisation of CuO nanorods via a hydrothermal method

CuO nanorods were synthesised on a large scale via a simple hydrothermal method. CuCl₂·2H₂O and cetyltrimethylammonium bromide (CTAB) were used as the copper source and surfactant, respectively. The microstructure and morphology of the CuO nanorods were examined by X-ray diffraction, Raman spectrum, field-emission scanning electron microscopy, transmission electron microscopy (TEM) and UV-vis spectrum. The CuO nanorods were monoclinic, and their diameter and length ranged from 20 to 30 nm and 150 to 200 nm, respectively. High resolution TEM and selected area electron diffraction results indicated that the CuO nanorods grow along the [010] direction. A possible growth mechanism for the formation of CuO nanorods was proposed. The concentration of surfactant CTAB in the solution was found to be a critical factor on the CuO morphology during the hydrothermal stage. The bandgap of the CuO nanorods was calculated to be 2.01 eV from the UV-vis spectrum.