β-Ni(OH)2 and NiO nanostructures: novel template-free synthesis and their photocatalytic activity

In this study, β-Ni(OH)2 nanostructures were synthesized by a facile and low cost gas-solution precipitation method using nickel(II) aqueous solution under ammonia atmosphere at room temperature, and later converted to NiO nanostructures via thermal decomposition. The products were characterized by X-ray diffraction, Fourier transformation infrared, photoluminescence and scanning electron microscopy techniques. The effects of initial concentrations and reaction times on the morphology and size of these nanostructures were also studied. The synthesized β-Ni(OH)2 and NiO in various shapes were effective catalysts for the degradation of methylene blue in the presence of H2O2 under ultraviolet irradiation.