Synthesis and characterization of (single- and poly-) crystalline NiO nanorods by a simple chemical route

Crystalline cubic NiO rods with diameter ranging from nanometer to few hundred nanometers and lengths up to 10 μm have been realized from a simple chemical route. The chemical reaction, of aqueous solutions of nickel chloride and sodium hydroxide with different molar ratios of NiCl2 and NaOH, formed the nickel hydroxide precursor which on thermal dehydration resulted in NiO nanocrystals with rod like morphology. The synthesized material has been characterized from XRD, SEM, TEM, EDAX and UV–vis absorption spectroscopy. The TEM micrographs show the rod like morphology of the formed crystals and the selected area electron diffraction pattern confirms the single-crystalline and polycrystalline nature of the observed rod like nanocrystals. The optical absorption band gap of NiO nanorods has been found to be of ∼3.62 eV.