Nanosized pseudoboehmite particles were synthesized by the precipitation of sodium sulfate and ammonia in aqueous solution at 70°C. After calcinations, the pseudoboehmite could successfully transfer to γ-Al2O3 nanoparticles while retaining their previous morphology. The influence of the reaction conditions on formation of pseudoboehmite and γ-Al2O3 had been researched in detail. The X-ray diffraction analysis showed that nanosized crystalline pseudoboehmite was formed at pH 8-8.5 after ageing 2 hours. Utilization of surfactant(PEG1000) would produce finer nanoparticles with well-dispersion. With the ageing time or the surfactant amount increasing, the morphology of the resulting particles transformed from spherical to fibrous

Using Al 2 (SO 4 ) 3 and urea [CO (NH 2 ) 2 ] as the starting materials, the self-assembled boehmite (γ -AlOOH) sphere with hollow structure was successfully synthesized by hydrothermal process. The effects of urea/Al 3+ molar ratios and hydrothermal treated time on the crystal structure, morphology and specific surface area were investigated in detail. It showed that the boehmite (γ -AlOOH) formed when the urea/Al 3+ molar ratio was 1:1, 2:1 and 3:1 hydrothermally treated at 180 • C for 24 h. The synthesized particles formed a hollow sphere structure with nano-flakelets surface and had the large specific area of 208 m 2 g −1 and high pore volume of 1.23cm 3 g −1 respectively.