Detailed Analysis of the Growth Kinetics of ZnO Nanorods in Methanol

The growth kinetics of ZnO nanorods in methanol is studied by a combination of scanning and high-resolution transmission electron microscopy and X-ray diffraction analysis. In the early stage of growth oriented attachment of 2-3 spheroidal crystallites to rod-like structures occurs Later, rods of up to 90 urn in length with a hexagonal cross-section up to 18 nut in diameter form by ripening Our main finding is that the growth follows a power law as a function of the ripening time with exponents of 0 32 to 0 39 for the length and 0.17 to 0 21 for the diameter In contrast to previous studies on the growth of ZnO rods in alcohols our results indicate that the growth is dominated by anisotropic Ostwald ripening that is limited by volume diffusion