Controlled growth of zinc oxide nanorods synthesised by the hydrothermal method

Using scanning electron microscopy, atomic force microscopy and X-ray diffraction, we investigated the morphology of ZnO (zinc oxide) films deposited via magnetron sputtering as a function of the chamber's operating pressure. We also studied how ZnO films, when used as templates, influence the morphology of zinc oxide nanorods (ZnO NRs) grown using the hydrothermal method. Our work shows that the resultant ZnO NRs were strongly affected by the initial ZnO film parameters (nanoparticle (NP) distribution and diameter) and, as a result, it was possible to tailor the final ZnO NR morphology by choosing the appropriate template and synthesis conditions. In particular, we showed that, using the hydrothermal method described here, the final ZnO NR mean diameter increased by ~ 20 nm from the value of the mean diameter of the NPs composing the starting ZnO template film.