Synthesis of Pyramid-Shaped NiO Nanostructures using Low-Temperature Composite- Hydroxide- Mediated Approach

Abstract

Composite-hydroxide-mediated (CHM) approach was used to synthesize NiO nanocrystals. The proposed method makes use of molten composite hydroxides; providing reaction media and lower the process temperature. Processing temperature and reaction time are the two potential parameters to control the growth of a nanomaterial. The method was used at temperatures in the range of 180-250°C and formation of the nanomaterial was monitored using XRD, SEM, EDX, FTIR, and UV-visible spectroscopy. The produced nanomaterial was purely polycrystalline with an average crystallite size in the range of 23.71-36.92 nm. Method suggested formation of pyramid shaped NiO nanocrystals in the temperature range 220-250°C. Evidence on the elemental composition, purity, and chemical bonding were obtained from EDX and FTIR analysis respectively. Estimation on direct bandgap was made from the optical analysis and found to be in the range 4.0-4.8 eV. The method is attractive and seems a cost effective route for the growth of transition metal oxides for research purpose. For further efficacy, the approach can be examined for other technologically significant nanostructures.