Adsorption properties of novel layered titanium phosphate prepared from mesoporous titania by sol–gel processing

A mesoporous titania material with a single X-ray diffraction signal at small-angle and anatase TiO₂ walls was prepared by a sol–gel method using hexadecylamine as a templating agent and titanium isopropoxide as a titanium precursor. The mesoporous solid was used to prepare a novel layered titanium phosphate by Soxhlet extraction reflux with phosphoric acid. The obtained α-TiP material showed a typical wide-angle X-ray diffraction pattern with a monoclinic structure, N₂ adsorption–desorption isotherms Type II, and large crystals of rectangular lamellae, confirming its layered nature by transmission electron microscopy. The elimination by adsorption of Hg²⁺ ions from aqueous samples was studied using Langmuir, Freundlich and Temkin models, calculating its different parameters. The adsorption of Hg²⁺ ions could be performed via active P-OH groups (observed by Fourier Transform Infrared results) in the lamellar structure showing excellent properties that make the layered material possible excellent adsorbent to remove heavy metals ions contaminants from potable water. [Figure not available: see fulltext.]