TRANSISI FASA TITATNIUM OKSIDA MELALUI KONDENSASI EX-SITU HIDROGEN TITANAT TIPE STRUKTUR LEPIDOKSROSIT

Abstract

The objectives of the research are to study of the structure type of titanium dioxide (TiO₂) obtained form the ex-situ condensation of hydrated hydrogen titanates with the structure type of lepidocrocite. Hydrated hydrogen titanates were obtained by ion exchabge of H⁺ for Cs⁺ in cesium titanates by 1 M HCl solution by Chimie Douce method. The results show that TiO₂ (B), anatase, and anatase-rutile mixture were obtained heat treatment of hydrated hydrogen titanate at 100, 200, 300, 500, and 600^oc respectively. The powders were characterized by X-rays diffractometer (XRD), High Resolution Scanning Electron Microscopy (HRSEM) and High Resolution Transmission Electron Microscopy (HRTEM). The research indicated that the protonic titanate, H_0.54 Ti_{1.865 0.135}O₄ 0.5H₂O ( =vacancy), lost the interlayer water by being heated up to 200^oC to produce a dehydrated phase, H_0.54 Ti_{1.865 0.135}O₄. Above 300^oC, the dehydrated phase completely transformed to TiO₂(B) and anatase was obtained as pure phase at 600^oC. The phase transformed as the following process: H_0.54Ti_{1.865 0.135}O₄ 0.5H₂O í  H_0.54Ti_{1.865 0.135}O₄ 0.25H₂Oí  H_0.54Ti_{1.865 0.135}O₄ í  TiO₂(B) í  TiO₂-anatase.