Fabrication of porous α-Ni(OH)2 microflowers by a facile template-free method

The porous α- Ni(OH)2 microflowers were successfully prepared by a facile solvothermal method without the utility of templates and additives. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TG) and nitrogen adsorption-desorption measurement. The obtained α- Ni(OH)2 products exhibited a flowerlike structure composed of porous petals with diameters of 1-3 μm. The novel nucleation-rapid aggregation-dissolution-recrystallization formation mechanism was proposed based on the experimental results. The α- Ni(OH)2 microflowers displayed large Brunauer-Emmett-Teller (BET) surface area of 252.4 m2/g. Furthermore, by annealing α- Ni(OH)2 precursors at 300 °C for 3 h in air, NiO was obtained with the designed morphology.