Synthesis of CuO nanorods via thermal decomposition of copper-dipicolinic acid complex

Template-free CuO nanorods were synthesized through a three-step chemical method with no water-insoluble materials. The first step included the preparation of a Cu-complex, which was obtained from dipicolinic acid, L-lysine, and copper nitrate. Then, as the second step, the obtained solution was allowed to be relaxed for a week to and formation of some blue single-crystals single crystals, which would be assigned as a square-pyramidal copper complex by according to study analyzing its single-crystal single crystal structure. Finally, as the third step, the blue prepared Cu-complex should be calcined to synthesis the CuO phase. Simultaneous thermal analysis (STA) was utilized to determine the optimum calcination temperature. Its results and showed that 600 ºC is the optimum temperature. X-ray diffraction (XRD) analysis approved the formation of the CuO phase without any impurity which is matched with the monoclinic CuO standard lines (PDF No.: 74-1021). Especially, the as-prepared CuO powder has shown clear nanorod morphology in transmission electron microscopy (TEM) images and exhibit a notable optical behavior and high band gap bandgap energy (Eg = 2.8 eV) in comparison to that of bulk CuO (Eg = 1.9-2 eV).