Synthesis of morphology controlled aluminum oxide by hydrothermal reaction

Plate-like and wire-like aluminum oxides were successfully synthesized by hydrothermal method without any template additives. Al(NO3)3·9H2O aqueous solution and precipitator were mixed and introduced to a Teflon lined autoclave, followed by heat treatment at 200°C for 24 h. By controlling the concentration of starting material and precipitator, the products with different morphologies were selectively obtained, i.e., the 2-dimensional platelike particles with a diameter of about 8μm were synthesized at low aluminum concentration (0.1 mol/L), while 1-dimensional wire-like products of about 10μm in length were synthesized at high aluminum concentration (0.2 mol/L). The plate-like particles and wire-like particles consisted of single phase of aluminum oxide hydroxide (boehmite, AlOOH) and the sodium aluminate, respectively.