Low temperature synthesis of nanocrystalline magnesium aluminate spinel by a soft chemical method

摘要

A new simple soft chemical method - synthesizing nanocrystalline MgAl_2O_4 spinel powder with oxalic acid as organic template and nitric acid as an oxidizing agent - is described. The method was developed with the objective of obtaining phase pure nanocrystalline MgAl_2O_4 spinel powder with uniform particle size and morphology at a much lower temperature than that used by conventional methods. The synthesized powders were characterized by X-ray diffractometry (XRD), thermogravimetry (TGA). Fourier transform infrared spectroscopy (FTTR), surface area analysis (BET) and field emission scanning electron microscopy (FE-SEM). The average crystallite size of the single phase material was 30 nm. Through this method, porous MgAl_2O_4 powder with a high surface area of 162.2 m~2g~(-1) and 141 m~2g~(-1) was obtained at 600℃ and 700℃, respectively.