2-Aminoethanol-mediated wet chemical synthesis of ZnO nanostructures

The synthesis of ZnO nanostructures via co-precipitation of Zn(NO3)(2)center dot 2H(2)O in 2-aminoethanol under different reaction conditions is presented. The effect of temperature and time on crystal structure, size, morphology, and optical properties of ZnO nanopowders is studied. XRD analyses demonstrate that single crystalline wurtzite ZnO nanostructures are instantaneously formed at higher temperature, or at low temperature with growth times equal to 2 h. However, the mean crystallite size increases as a function of reaction temperature and growth time. XRD and SEM results reveal that ZnO nuclei grow along favored crystallographic planes [wurtzite (101)] in 2-aminoethanol to form single crystalline nanorods. The optical band-gap energies of ZnO crystallites measured from their UV absorption spectra increase from 3.31 to 3.52 eV with decreasing particle size. ZnO nanopowders also exhibit good photoluminescent characteristics with strong UV and weak visible (violet, blue) light emissions corresponding to surface defects and oxygen vacancies in ZnO products.