Small lanthanide-doped Sr2YbF7 nanocrystals: Upconversion fluorescence and upconversion-driven photodegradation

摘要： A series of lanthanide-doped Sr2YbF7 nanocrystals were prepared conveniently via a solvothermal method using oleic acid as the stabilizing agent, which were about 15 nm of the average crystalline size at 200 °C and 24 h. Through screening the doped lanthanide ions and their concentrations, we found that the nanocrystals realized intense ultraviolet, visible and near-infrared upconversion emissions under 980 nm excitation. Based on the photo-physical property of the nanocrystals, we built the hybrid Sr2YbF7: Tm3+@TiO2 to successfully realize upconversion-driven photo-degradation of Rhodamine B, in which semiconducting TiO2 took advantage of the light emitted by Sr2YbF7: Tm3+ to produce the electron-hole pairs.