2. Experimental procedure
2.1. Materials
The following chemicals zinc nitrate (99% purity, Merck),potassium hydroxide (85% purity, Merck), lead acetate and phenolphthalein were procured from Merck and used without further purification.
2.2. Microwave assisted synthesis procedure All the chemicals and reagents used in this experiment were of analytical grade and used without further purification. Prepara-
tion process of nano ZnO rods in our study is as follows: 29.749 g of zinc nitrate was dissolved in 200 ml of double distilled water.
Then 1 M KOH prepared in DD water was added dropwise very slowly into the zinc nitrate aqueous solution at a stirring rate of 500–520 rpm till the required pH of 13, 11 and 9 was attained.
Also, when the viscosity of the mixture increases, the revolution of the Teflon was so adjusted to maintain the stirring rate of 500– 520 rpm throughout the experiment.
After the addition was completed, the stirring was continued for another 30 min at
60 1C.
During stirring a milky white suspension of Zn(OH)2 was obtained.
The above solution was kept overnight at room temperature and the precipitate was filtered, washed thoroughly with