Effect of colloid characteristics on the fabrication of ZnO nanowire arrays by electrophoretic deposition

Abstract

In this study ZnO colloidal suspensions with varied characteristics were synthesized by varying the amount of added sodium hydroxide. The template-mediated preparation for nanosized ZnO arrays was conducted by electrophoretic deposition in the nanochannels of anodic alumina membranes. The effect of colloid characteristics on the deposition of ZnO nanowire arrays was investigated, and the related deposition mechanisms, morphologies and optical properties of the deposits were discussed. The deposited ZnO nanoarrays were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) studies. It was found that both the morphology and the deposition rate of ZnO nanowire arrays were influenced by the pH of the suspension and the applied voltage. The particle surface charge and size changed with the pH of the suspension, which in turn affected the deposition characteristics. The deposition rate of nanowire arrays was high at the initial stage and then approached a saturation value. The deposition rate also increased with increasing zeta potential of the particles and the applied voltage for EPD of ZnO nanowires. The photoluminescence properties of ZnO arrays were largely determined by particle size and surface properties of the nanoparticles comprising the nanowire arrays.