A diffusion-controlled kinetic model for growth of Au-catalyzed ZnO nanorods: Theory and experiment

A kinetic model for growth of ZnO nanorods via vapor–liquid–solid (VLS) mechanism based on the bulk diffusion of Zn atoms through the Au–Zn droplet is presented. The dependences of the growth rate on size are given quantitatively. A general expression for the growth rate of nanorods during VLS process is derived. The derived formula shows the dependences of growth rate on lateral size of nanorods, concentration and supersaturation of Zn atoms in the liquid droplet. Based on the presented kinetic model the smaller nanorods have faster growth rate. Au-catalyzed ZnO nanorods are grown by chemical vapor transport and condensation (CVTC) process experimentally. Theoretical and experimental rate/radius curves are compared to each other. Theoretical predictions are in good agreement with the experimental results.