Controlled synthesis and. self-assembly of single-crystalline CuO nanorods and nanoribbons

We report several wet-chemical methods for synthesis of one-dimensional CuO nanostructures in water-ethanol mixed solvents at 77-82 degreesC and 1 atm. Single-crystalline monodispersed CuO nanorods with a selected breadth in the range of 5-15 nm have been prepared by controlling reagent concentrations. The nanorods are preferentially grown along <010> directions. A two-step continuous process has also been developed to prepare CuO nanorods and ribbons (length up to 1 pm) with a large aspect ratio under pseudo-steady-state operation. Furthermore, a two-dimensional netted structure has been assembled for the first time from short nanorods formed after prolonged aging; the nanorods are attached each other using their {001}, {100}, and {110} crystal planes. With concentrated NaOH used in synthesis, the nanorods can also be extended along <100>, which gives rise to the formation of CuO nanoplatelets. Various synthetic parameters have also been investigated.