Pore size control for mesoporous titanium hydroxide prepared with mixed template molecules and its fluoride ion exchange property

Abstract

Control of pore size on mesoporous titanium hydroxide denoted as TiO X (OH) 2+ δ with zirconium additive was studied by using different size template molecules. The mesopore diameter of TiO X (OH) 2+ δ increased monotonically with increasing size of the organic template molecule used. The use of a mixture of template molecules with different size allowed for accurate pore size control of TiO X (OH) 2+ δ . Moreover, a pore size between those of single template molecules was obtained using a mixture of two different template molecules. The fluoride ion exchange capacity of Zr-added TiO X (OH) 2+ δ also increased with increasing mesopore diameter, and the largest fluoride ion exchange capacity was achieved on the sample with 3.34 nm pore size, and the fluoride ion exchange capacity was further improved by the accurate control of pore size. The amount of fluoride ions adsorbed was 1.1 mmol/g against 50 ppm NaF solution; this was observed in TiO X (OH) 2+ δ with 4.2 nm pore size, which was obtained using a 3:1 mixture of C 12H 25NH 2:C 14H 29NH 2 as the template molecule.