Morphological control of mesoporous alumina nanostructures via template-free solvothermal synthesis

Mesoporous alumina nanostructures with tunable morphologies have been synthesized using different solvents through the template-free solvothermal approach. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and nitrogen adsorption/desorption were used to characterize the samples. By manipulating the volume ratio and the composition of the reaction solvent, various morphologies of mesoporous alumina with crystalline-framework walls, i.e. nanotubes, nanofibers, nanorods, nanolaths, and nanosheets were synthesized. The specific surface area and the pore size correlated with the morphologies of γ-alumina nanocrystals. In comparison with conventional surfactant-templating methods, the new approach is simple and more suitable for industrial scale production.