Strong photoluminescence and sensing performance of nanosized Ca0.8Ln0.1Na0.1WO4 (Ln = Sm,Eu) compounds obtained by the dry "top-down" grinding method

Abstract

Two lanthanide doped nanosystems Ca0.8Ln0.1Na0.1WO4 (Ln=Eu, Sm), denoted as Eu@CWO and Sm@CWO, were prepared by a “top-down” approach in three simple steps which included activation, miniaturization by high-energy milling, and further calcination. The solids were thoroughly characterized by X-ray powder diffraction (XRPD), Raman spectroscopy and scanning-electron microscopy (SEM). Also, analyses of the compounds’ structure and the impact of the milling on crystallite shape and size were carried out through Rietveld refinements. The solid-state photoluminescence was studied in terms of excitation, emission, lifetimes (obs) and europium-quantum yields. Finally, the Eu@CWO sample was employed as potential water-stable chemical sensor towards toxic cations, finding a quenching effect in the presence of iron ions