Synthesis of Titanate Derivatives Using Ion‐Exchange Reaction

Two types of titanate derivatives, layered hydrous titanium dioxide (H 2 Ti 4 O 9 · n H 2 O) and potassium octatitanate (K 2 Ti 8 O 17 ) with a tunnellike structure, were synthesized using an ion‐exchange reaction. Fibrous potassium tetratitanate (K 2 Ti 4 O 9 · n H 2 O) was prepared by calcination of a mixture of K 2 CO 3 and TiO 2 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 H 2 Ti 4 O 9 · n H 2 O through an exchange of K + ions with H + ions using HCl. K 2 Ti 8 O 17 was formed by a thermal treatment of KHTi 4 O 9 · n H 2 O. Pure KHTi 4 O 9 · n H 2 O phase was effectively produced by a treatment of K 2 Ti 4 O 9 with 0.005 M HCl solution for 30 min. Thermal treatment at 250°–500°C for 3 h resulted in formation of only K 2 Ti 8 O 17 .