Exfoliation and europium(III)-functionalization of α-titanium phosphate via propylamine intercalation: from multilayer assemblies to single nanosheets

• DOI: 10.1007/s10450-019-00133-2
• Publication Date: 2019-06-19T12:05:35Z
• Authors: Jorge García-Glez; Camino Trobajo; Alaa Adawy; Zakariae Amghouz
• Keywords: Europium; Propylamine; Selected area diffraction; Exfoliation joint; Surface Modification

Financial support from Spanish Ministerio de Economía y Competitividad (MAT2013-40950-R and MAT2016-78155-C2-1-R) and Gobierno del Principado de Asturias (GRUPIN14-060), and FEDER funding are acknowledged.<br/>Peer reviewed<br/>Layered α-titanium phosphate intercalated with propylamine, Ti(HPO4)2·2C3H7NH2·H2O (α-TiPPr), has been synthesized by solid-vapour reaction and then exfoliated via a single-stage approach based on overnight stirring in aqueous medium. The obtained nanosheets were then functionalized using solid–liquid reaction with europium(III) nitrate aqueous solutions. The obtained materials were characterized by powder X-ray diffraction (PXRD), N2 adsorption–desorption isotherms at 77 K, scanning electron microscopy (SEM), transmission electron microscopy (TEM, SAED, STEM-EDX), atomic force microscopy (AFM) and photoluminescence spectroscopy (PL). The europium(III) sorption takes place via two distinct pathways, the first is the previously reported C3H7NH3+/[Eu(H2O)6]3+ ion-exchange process into the titanium–phosphate interlayer space of the multilayered α-TiPPr. The second pathway is the self-assembly of single-sheets which is provoked by electrostatic interactions between the negatively charged titanium–phosphate sheets and the Eu(III)-aqueous cations, leading to the formation of layered nanoparticles.<br/>