A facile solvothermal route to synthesis of γ-alumina with bundle-like and flower-like morphologies

Boehmite with bundle-like morphology assembled from nanofibres has been successfully synthesized by solvothermal method from AlCl3·6H2O in ethylene glycol (EG) at 200 °C for 10 h. Using 1,4-Butanediol instead of EG, the Al11(OH)30Cl3 with flower-like morphology assembled from nanosheets was obtained at 200 °C for 6 h. The γ-alumina with similar morphology was obtained by thermal decomposition of the boehmite or Al11(OH)30Cl3 at 500 °C for 3 h in air. The products were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectrometry (FTIR), transmission electron microscopy (TEM), and thermogravimetric analysis (TG). The method is simple and does not need any surfactant or template or base.