Facile synthesis of zinc carbonate and zinc oxide nanoparticles via direct carbonation and thermal decomposition

Synthesis of ultrafine zinc carbonate and zinc oxide powders using direct precipitation and thermal decomposition of the precursor was investigated. Nanoparticles of ZnCO3 were prepared by the direct precipitation method with Zn(NO3)2 and Na2CO3 as raw materials. The precipitation process as a popular, facile, controllable and cost-effective method was used to produce insoluble inorganic salts. Therefore, it was very important to improve capability and quality of the process for controlling the product particle size by setting the optimal precipitation reaction parameters. In this research, the parameter design of the Taguchi method was applied to set the optimal parameters of precipitation process for zinc carbonate nano-particle preparation. The reaction conditions such as zinc and carbonate ion concentrations, flow rate of reagent addition and reactor temperature were optimized by orthogonal array design, OA9. The effect of these factors on the size of ZnCO3 nanoparticles was quantitatively evaluated by the analysis of variance (ANOVA). The results showed that ZnCO3 nanoparticles can be synthesized via direct carbonation process by controlling zinc and carbonate ion concentrations and flow rate of reagent addition. The experimental results for preparation of nano-particles of ZnCO3 showed that the minimum size was about 15 nm and the maximum was about 70 nm. In the next step of this study, an efficient one-step thermal decomposition method was described for preparation of ZnO nanoparticles from zinc carbonate precursor. The prepared ZnCO3 and ZnO particles were characterized using X-ray diffraction (XRD), SEM, FT-IR and thermal analysis techniques.