Thermal behavior of layered α-titanium phosphates: from the titanium(IV) bis(hydrogenphosphate) monohydrate to an europium(III)-phase via propylamine intercalation

Abstract

Polycrystalline layered α-titanium phosphate, α-Ti(HPO4)2·H2O, has been obtained under H3PO4(aq) reflux conditions, and its intercalation compound with propylamine, α-Ti(HPO4)2·2C3H7NH2·H2O, was used for trapping luminescent Eu-centers in two-dimensional confined space. All materials were characterized by X-ray powder diffraction, scanning electron microscopy, solid-state nuclear magnetic resonance (SS-NMR, 31P MAS and 13C CPMAS) and thermogravimetric analysis coupled with mass spectrometry. Moreover, the activation energy of thermal decomposition has been calculated as a function of the extent of conversion, applying both a modified Friedman method developed in our laboratory and the advanced nonlinear method proposed by Vyazovkin.