Characterization of nanocrystalline ZnO flakes synthesized by a simple reaction process

Abstract

In this research, nanocrystalline ZnO flakes were synthesized via a simple reaction process by using zinc acetate dihydrate, diethyl amine and sodium hydroxide. It is confirmed by scanning electron microscopy analysis that nanocrystalline ZnO flakes are flat, irregular in shape, have a high thickness and their average dimension is about 300 nm. The X-ray diffraction (XRD) and FT-IR results indicated that the synthesized ZnO product has the pure wurtzite structure with lattice parameters a and c of 3.253 and 5.210 Å, respectively. The average crystallite size of the ZnO nanostructures deduced from the Scherrer formula is ~31 nm. Raman scattering exhibits a sharp and strong E2H mode at 438 cm-1 which further confirms the good crystallinity and wurtzite hexagonal phase of the prepared ZnO nanostructures. The synthesized powder exhibited the UV absorption at around 370 nm with the estimated direct band gap energy of 3.278 eV. The particle size was also deduced by using the Brus equation and the estimated band gap energy of the ZnO nanopowder sample. The obtained value is in agreement with the calculated one from the Scherrer formula. The strain in the ZnO nanoparticles was also calculated. © 2013 Hosokawa Powder Technology Foundation.