Synthesis of Different Cu(OH)2 and CuO (Nanowires, Rectangles, Seed-, Belt-, and Sheetlike) Nanostructures by Simple Wet Chemical Route

We report the synthesis of different Cu(OH)2 and CuO nanostructures (nanowires, rectangles, seedlike, beltlike, and sheetlike) in a solution phase with high yield at low cost by simple reduction of aqueous solution of copper nitrate (Cu(NO3)2 = 0.2 M) with different alkaline solutions of sodium hydroxide (NaOH = 0.1, 0.25, 0.50, 0.75, and 1.0 M). The morphology of the synthesized nanostructures is significantly influenced by the feeding concentration of alkaline NaOH solution. Cu(OH)2 rectangles and nanowires can be readily obtained by the reduction of Cu(NO3)2 solution with different molar concentrations of NaOH solution and the synthesized nanomaterials get transformed into different nanostructures of CuO by subsequent heat treatment at 80 °C for half an hour. Well-defined rectangle-like structures of hydrated copper hydroxide Cu(OH)2·H2O and different CuO nanostructures, such as seedlike, beltlike, and sheetlike, were synthesized by thermal dehydration of corresponding different shaped and sized Cu(OH)2 nanomaterials. The Raman spectra of different CuO nanomaterials obtained at different molar concentrations of NaOH (0.25, 0.50, 0.75, and 1 M) were recorded in the region 1050−1300 cm−1. A tentative mechanism has been given for the formation and transformation of different nanostructures.