New pore structure of nano-alumina (Al2O3) prepared by sol gel method

Abstract

Nano-porous alumina ceramics were fabricated using a simple and new sol-gel method. Aluminium oxide (Al2O3) nanoporous templates were synthesized by iron (III) nitrate 9-hydrate and aluminium isopropoxide as precursor. The samples were characterized by high resolution transmission electron microscopy (HRTEM), field effect scanning electron microscopy (FESEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and UV-Vis spectrophotometer. XRD technique was used to identify α-alumina and γ-alumina. XRD pattern exhibited gamma-Al2O3 to alphaAl2O3 structural phase transition in nanoporous. The particle size of spherical as-prepared Al2O3 was measured around 20 nm by direct HRTEM observation. The surface morphological studies depicted the samples changed from sphere-like shaped to sponge-like pore structure by increasing annealing temperature. The sharp peaks in FTIR spectrum determined the purity of Al2O3 nanoparticles and absorbance peak of UV-Vis spectrum showed the small bandgap energy of 2.61 ev.