Preparation and characterization of nanoplatelets of nickel hydroxide and nickel oxide

A novel room-temperature coordination–precipitation technique was successfully developed for the synthesis of nickel hydroxide (theophrastite) nanoplatelets. This method has great potential for large-scale industrial production owing to facile size-controlled and low-cost. This platelet-like nickel hydroxide precursor can readily be converted to nickel oxide (bunsenite) nanoplatelets after 400 °C calcining. The synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetry–differential thermal analysis (TG–DTA) and X-ray photoelectron spectroscopy (XPS) techniques. The thickness of β-Ni(OH)2 nanoplatelets can be controlled by changing concentration of precipitant NaOH in the presence of ethylenediamine. The formation of Ni(en)32+ complex ions in solution prior to precipitating nickel hydroxide may play a crucial role in controlling phase composition of resulting precipitate.