Synthesis of α-Ni(OH)<sub>2</sub> Peonies Assembled from Nanosheet Building Blocks and Corresponding NiO Porous Peonies

α-Ni(OH) 2 peonylike structures assembled from nanosheets with thickness of 10nm were successfully synthesized via a hydrothermal method. The corresponding NiO peonylike structures with similar morphology to the α-Ni(OH) 2 precursor were also be fabricated by thermal decomposition of the as-synthesized α-Ni(OH) 2 at 350°C for 2 h in air. Samples are thoroughly characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrum, Brunauer-Emmett-Tellermethod (BET), and thermogravimetric analysis (TGA). The BET surface area for α-Ni(OH) 2 and NiO are 36.0m 2 /g and 120.2 m²/g, respectively.