Eu2+-doped BaAlF5 nanophosphors were synthesized via a facile one-pot hydrothermal method. The final products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD results showed that the prepared samples are single-phase. The FE-SEM and TEM images indicated that the prepared BaAlF5:Eu2+ nanophosphors are composed of many rice-shaped particles with an average diameter of 40 nm. When excited at 260 nm, BaAlF5:Eu2+ nanophosphors exhibit the sharp line emissions of Eu2+ at room temperature. The optimum doping concentration of Eu2+ was confirmed to be 5 mol%. The Van and Huang models were used to study the mechanism of concentration quenching and the electric dipole dipole interaction between Eu2+ can be deduced to be a dominant for quenching fluorescence in BaAlF5:Eu2+ nanophosphors. The strong ultraviolet emission of Eu2+ in BaAlF5:Eu2+ nanophosphors suggests that these nanoparticles may have potential applications for sensing, spectrometer calibration and solid-state lasers. (C) 2014 Elsevier Ltd. All rights reserved.