Optimization of process parameters and its effect on particle size and morphology of ZnO nanoparticle synthesized by sol–gel method

In the present work, a systematic basic research has been performed for finding out the effect of various process parameters viz. molar ratio of zinc sulfate and sodium hydroxide, reaction time and calcination temperature on size and morphology of ZnO nanoparticles synthesized using zinc sulfate as a precursor by sol–gel method. Taguchi design method, ANOVA and regression analysis were used to find out the effect of various process parameters on the response in terms of narrow particle size distribution and crystal size. Characterization was done to find out the response such as particle size distribution and crystal size by using TEM and XRD. Results revealed molar ratio of 1:2, and calcination temperature of 700 °C could significantly form uniform-sized spherical ZnO nanoparticles (85 nm) with narrow size distribution. However, significant increase in crystal size of ZnO nanoparticles was observed with increase in calcination temperature from 300 to 700 °C. This may be primarily due to governing of higher diffusion rate at high temperature which resulted in enhanced growth rate of ZnO crystals.