Markova-Velichkova M.,Academy G Bontchev Str Bd |
Veleva S.,Academy G Bontchev Str Bd |
Tumbalev V.,Academy G Bontchev Str Bd |
Stoyanov L.,Academy G Bontchev Str Bd |
And 4 more authors.
Bulgarian Chemical Communications | Year: 2013
Three different synthesis techniques were applied in order to prepare ZnO powder samples with different crystallite size. The first method is thermal decomposition of Zn(NO3)2.6H2O. The second synthesis method is a sucrose-assisted solution combustion method. The third technique used is ultrasound assisted precipitation. A short-time thermal treatment is used to obtain ZnO materials with the required mean crystallite size. Materials were studied by means of powder XRD and TEM. The detailed morphology of the materials was first studied by XRD utilizing the special features of Fullprof program. This study revealed that different synthesis methods lead to products with different morphology. Materials obtained by the first method have an average crystallite size of 130-150 nm with irregular but isometric shape of the crystallites, while those obtained by the second method are almost spherical particles with size of about 30-40 nm. Regardless of the similar average crystallite size of the material obtained by the third method, its morphology is spindle-like, derived from different broadening of the XRD lines. The results from XRD analyses were confirmed by TEM observations. The influence of crystal morphology on the performance of ZnO as a main active material in zinc electrodes is discussed. © 2013 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria. Source