Fabrication of ZnO microtubes with adjustable nanopores on the walls by the templating of butterfly wing scales

ZnO microtubes with adjustable arrayed nanopores on the walls are prepared by using butterfly wing scales as natural biotemplates. Flat butterfly wing scales used as templates rolled into tubes during the calcinations; all the windows on the scales were reserved and formed porous walls. Furthermore the density of the pores on the walls is partially determined by experimental conditions, such as temperature and time of treatment. The nano/microstructures obtained have been investigated by means of x-ray diffraction and field emission scanning electron microscopy. The room temperature (T = 300 K) cathodoluminescence of these unique ZnO microtubes is also studied. The spectrum shows a sharp near band edge emission and a broad deep level emission, which are similar to those for other previously synthesized ZnO microtubes.