Synthesis of ZnO nanorod/nanotube arrays formed by hydrothermal growth at a constant zinc ion concentration

In the hydrothermal growth of macroscopic arrays of I-dimensional zinc oxide on seeded substrates the morphology of the individual nanoparticles changes during the reaction, typically nanorods taper to nanotubes for reaction times in excess of 3 hours. In this paper it is demonstrated that by keeping the zinc ion concentration in the reaction solution constant, using potentiostatically controlled dissolution of a sacrificial zinc working electrode, during the precipitation of zinc oxide, it is possible to synthesise arrays of 1-dimensional zinc oxide particles which have a constant diameter along their entire length, even after 10 hours of growth. These finding indicate the importance of the concentration of zinc ions in determining the morphology of the deposited nanorods. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim