Kolesnik Stefaniia S, Nosov Viktor G, Kolesnikov Ilya E, Khairullina Evgenia M, Tumkin Ilya I, Vidyakina Aleksandra A, Sysoeva Alevtina A, Ryazantsev Mikhail N, Panov Maxim S, Khripun Vasiliy D, Bogachev Nikita A, Skripkin Mikhail Yu, Mereshchenko Andrey S
Saint-Petersburg State University, 7/9 Universitetskaya emb., 199034 St. Petersburg, Russia.
Sirius University of Science and Technology, 1 Olympic Ave, 354340 Sochi, Russia.
Nanomaterials (Basel). 2021 Sep 20;11(9):2448. doi: 10.3390/nano11092448.
The luminescent coarse-, micro- and nanocrystalline europium(III) terephthalate tetrahydrate (Eubdc·4HO) metal-organic frameworks were synthesized by the ultrasound-assisted wet-chemical method. Electron micrographs show that the europium(III) terephthalate microparticles are 7 μm long leaf-like plates. According to the dynamic light scattering technique, the average size of the Eubdc·4HO nanoparticles is equal to about 8 ± 2 nm. Thereby, the reported Eubdc·4HO nanoparticles are the smallest nanosized rare-earth-based MOF crystals, to the best of our knowledge. The synthesized materials demonstrate red emission due to the D-F transitions of Eu upon 250 nm excitation into ππ* state of the terephthalate ion. Size reduction results in broadened emission bands, an increase in the non-radiative rate constants and a decrease in both the quantum efficiency of the D level and Eu and the luminescence quantum yields. Cu, Cr, and Fe ions efficiently and selectively quench the luminescence of nanocrystalline europium(III) terephthalate, which makes it a prospective material for luminescent probes to monitor these ions in waste and drinking water.
采用超声辅助湿化学法合成了发光的粗晶、微晶和纳米晶铕（III）对苯二甲酸四水合物（Eubdc·4H₂O）金属有机骨架材料。电子显微照片显示，铕（III）对苯二甲酸微粒为7μm长的叶状薄片。根据动态光散射技术，Eubdc·4H₂O纳米颗粒的平均尺寸约为8±2nm。据我们所知，所报道的Eubdc·4H₂O纳米颗粒是最小的纳米尺寸稀土基金属有机骨架晶体。合成材料在250nm激发下，由于铕的D-F跃迁进入对苯二甲酸根离子的ππ*态而呈现红色发射。尺寸减小导致发射带变宽、非辐射速率常数增加以及D能级和铕的量子效率和发光量子产率降低。铜、铬和铁离子能有效且选择性地猝灭纳米晶铕（III）对苯二甲酸的发光，这使其成为监测废水和饮用水中这些离子的发光探针的潜在材料。
