Hollow MgO nanotube arrays by using ZnO nanorods as templates

A newly developed solid-gas chemical reaction route has been demonstrated to fabricate MgO nanotube arrays by using prefabricated ZnO nanorods as templates. The formation process involves the Kirkendall effect, in which the out-diffusion of the ZnO core material through the MgO shells is faster than the in-diffusion of the vapor-phase Mg atoms, resulting in the formation of Kirkendall voids, which eventually induces hollow MgO nanotubes. The dimensions and sizes of the obtained MgO nanotubes can be controlled by employing suitable ZnO templates. Other types of complex hollow MgO architectures with different aspect ratios can be further manipulated and fabricated by this method, depending on the morphologies of the starting ZnO nanostructures used as templates. These hollow MgO architectures with high surface-to-volume ratios may have promising applications in catalysis, drug delivery, nano-optics, nanoreactors, and active material encapsulation. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008.