Microwave-assisted hydrothermal synthesis of Ni(OH)2 architectures and their in situ thermal convention to NiO

The Ni(OH)2 architectures with flower-like morphology assembled from nanosheets have been successfully synthesized through a microwave-assisted hydrothermal method using urea as a hydrolysis-controlling agent and polyethylene glycol (PEG) as a surfactant. The NiO architectures with similar morphology were obtained by a simple thermal decomposition process of the precursor Ni(OH)2. The as-obtained products were well characterized by XRD, TG-DTA, SEM, TEM, FTIR and UV–Vis. The experimental results shown that flower-like Ni(OH)2 architectures with a diameter of 2.5–4.0 μm are assembled from nanosheets with a thickness of 10–20 nm and width of 0.5–1.5 μm. The UV–Vis experimental results shown that the absorption edge of the NiO architectures have a blue-shift with the increasing of the calcination temperature.