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 double distilled water several times.
The filtrates were tested for the absence of pink color with phenolphthalein and white precipitate with lead acetate.
Then the obtained precipitates were dried at 60 1C and then suspended in 100 ml of double distilled water in a 1000 ml beaker and irradiated with microwaves using a domestic microwave oven (Samsung MW 73 V) at 180W for 30 min.
The resultant precipitates were filtered and then calcined at 200 1C under a vacuum oven for two hours.
The products obtained from three different precursor solutions of pH 13, 11 and
9 were named as A1, A2 and A3 respectively. The crystallinity and phase identification of the samples were analyzed using powder X-ray diffraction in steps of 0.051 in 2y range of 10–801 with Ka radiation (l¼1.5406 ˚A) using X’Pert X-ray diffractometer.
The morphology of the as-synthesized product was investigated using Quanta 200 FEG High Resolution Scanning Electron Microscopy (IIT, Chennai).
The optical properties of the samples were studied by recording the Diffused Reflectance Spectra using