Phase purity and grain size were determined by x-ray
diffraction (XRD) analysis recorded on a Siefert x-ray
diffractometer (Richard Seifert & Co, Ahrensburg, Germany)
using CuKα radiation (λ = 1.54016 Å) at 60 keV over the range
of 2θ = 20–80 degrees. The average grain size of the ZnO
nanoparticles was determined by using the Debye-Scherrer (DS)