Synthesis and characterization of hollow metal oxide micro-tubes using a biomaterial template

Various hollow metal oxide micro-tubes (SnO2, ZrO2, ZnO, and NiO) were prepared by a simple impregnation method using Ceiba pentandra (L.) Gaertn. (kapok) as a biomaterial template. Calcination heat treatment was successfully used for the removal of the kapok template. Field emission scanning electron microscopy (FE-SEM) was used to study the uniform morphology of the hollow metal oxide micro-tubes, which had an average diameter of 15–20 μm. The hollow metal oxide micro-tubes were further characterized by thermal gravity analysis (TGA), X-ray diffraction (XRD), and X-ray photo-electron spectroscopy (XPS). This synthesis method provides a new facile route for the fabrication of hollow metal oxide micro-tubes.