Preparation of Titanium-Containing Layered Alkali Silicates

Titanium-containing layered alkali silicates (magadiite and octosilicate) were synthesized by the hydrothermal reactions of silica gel, sodium hydroxide, and titanium tetrachloride. The Si/Ti ratios of 50-200 were examined to find the amount of Ti to be incorporated into the silicate frameworks by substituting Si. The location of Ti was confirmed by the UV-vis absorption and XAFS measurements. The incorporated Ti existed as tetrahedrally coordinated species surrounded with oxygen in the silicate layers at the low Ti content for both magadiite and octosilicate, where the upper limit of the framework incorporation was lower than Si/Ti = 50.