Simple Template-Free Solution Route for the Controlled Synthesis of Cu(OH)₂ and CuO Nanostructures

The controlled synthesis of Cu(OH) 2 nanowires and nanoribbons in a solution phase has been realized with high yield at low cost by simply dropping KOH and ammonia solutions into an aqueous solution of CuSO 4 at ambient temperature. It is demonstrated that the morphology of nanostructured Cu(OH) 2 is significantly influenced by the feeding manner of the alkaline solutions. A rational mechanism based on coordination self-assembly and oriented attachment is proposed for the selective formation of the polycrystalline Cu(OH) 2 nanowires and single-crystalline Cu(OH) 2 nanoribbons. In the presence of a polymeric additive, poly(acrylic acid) (PAA), ordered assemblies of Cu(OH) 2 nanorods can be readily obtained. Furthermore, well-defined CuO nanostructures, such as CuO nanoplatelets, nanoleaflets, and nanowires, were produced by thermal dehydration of the as-prepared Cu(OH) 2 nanostructures in solution or in the solid state. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize the products.