Synthesis of Barium Titanate Nanoparticles from Decomposition of Barium Titanyl Oxalate Tetrahydrate with Aid of Supercritical Water

Abstract

A novel process of BaTiO3 manufacture was conducted by using supercritical water. Preparation of BaTiO3 nanoparticles was investigated from decomposition of BaTiO(C2O4)2•4H2O (BTOT) with aid of supercritical water for the first time. When BTOT was exposed to supercritical water around 673 K and 30 MPa, it decomposed quickly in 5-22 seconds. The products formed strongly reply on environmental conditions. BaCO3 and TiO2 were always observed as the products in the absence of alkaline additives. BaTiO3 nanoparticles with specific surface area as high as 12~14 m2/g were able to be obtained under strong alkaline conditions, such as NaOH/COSubscript text2=2/1. It was found that environment of supercritical water was better than sub-critical conditions to obtain high quality BaTiO3 particles with fewer defects. Employment of supercritical water significantly reduced the reaction time and temperature compared to other BaTiO3 manufacture processes utilizing BTOT as precursor.