Thermal Decomposition of Chemically Precipitated Aluminum Hydroxide Nanopowder

The processes of phase formation of aluminum oxide nanopowder during the thermal decomposition of chemically precipitated aluminum hydroxide are considered in detail. It is shown that precipitated aluminum hydroxide has a flake morphology with an average particle diameter of 5.5 nm and is characterized by a complex phase composition. According to the results of differential thermal analysis, it is found that freshly precipitated aluminum hydroxide consists of two phases, bayerite α-Al(OH)3 and aluminum oxyhydroxide AlOOH, the thermal decomposition of which leads to the formation of γ-Al2O3 with an equiaxed particle shape and an average size of 7 nm.