Influence of solvent on the growth of ZnO nanoparticles.

We have synthesized ZnO nanoparticles by precipitation from zinc acetate in a series of n-alkanols from ethanol to 1-hexanol as a function of temperature. In this system, nucleation and growth are relatively fast and, at longer times, the average particle size continues to increase due to diffusion-limited coarsening. During coarsening, the particle volume increases linearly with time, in agreement with the Lifshitz-Slyozov-Wagner (LSW) model. The coarsening rate increases with increasing temperature for all solvents and increases with alkanol chain length. We show that the rate constant for coarsening is determined by the solvent viscosity, surface energy, and the bulk solubility of ZnO in the solvent.