Synthesis of Titanate Derivatives Using Ion-Exchange Reaction

Two types of titanate derivatives, layered hydrous titanium dioxide (H₂Ti₄O₉· n H₂O) and potassium octatitanate (K₂Ti₈O₁₇) with a tunnellike structure, were synthesized using an ion-exchange reaction. Fibrous potassium tetratitanate (K₂Ti₄O₉· n H₂O) was prepared by calcination of a mixture of K₂CO₃ and TiO₂ with a molar ratio of 2.8 at 1050°C for 3 h, followed by boiling-water treatment of the calcined products for 10 h. The material then was transformed to layered H₂Ti₄O₉· n H₂O through an exchange of K⁺ ions with H⁺ ions using HCl. K₂Ti₈O₁₇ was formed by a thermal treatment of KHTi₄O₉· n H₂O. Pure KHTi₄O₉· n H₂O phase was effectively produced by a treatment of K₂Ti₄O₉ with 0.005 M HCl solution for 30 min. Thermal treatment at 250°–500°C for 3 h resulted in formation of only K₂Ti₈O₁₇.