Solvothermal synthesis of ZnO with various aspect ratios using organic solvents

Nanocrystalline ZnO powders were synthesized by a solvothermal method using various organic solvents as the reaction medium. Products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). The aspect ratio of ZnO primary particles depended upon the solvent employed, such that the aspect ratio increased when the solvent with a low dielectric constant was employed. For the use of n-alkanes and aromatic compounds as solvent, ZnO nanorods were obtained. The polar characteristic of the solvent was proposed to be the main factor that affects both nucleation and growth of ZnO nanoparticles and, consequently, determines the aspect ratio of the products.