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 °C 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 μm) 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.