Zi Chen,Dongdong Lu,Hangqing Xie,Xiaolei Yang,Yang Li,Chenhao Bao,Lei Lei,Shiqing Xu
The increasing demand for radiation detection in many applications has led to demanding requirements for scintillators. Realizing low-dose, pollution-free, and reliable X-ray detection has become a key technical challenge. Here, a triplet-enhanced lanthanide radioluminescence (RL) material Ga 3+ /Tb 3+ metallacrowns (Tb-1) is reported. This Tb-1 crystal emits bright green luminescence under ultraviolet light or X-ray excitation, and the emission intensity is 286 and 242 times that of Tb 3+ in inorganic salt, respectively. Tb-1 crystal is further passivated by trioctylphosphine oxide (TOPO), and the enhanced RL intensity is equivalent to that of commercial Tl-doped cesium iodide scintillator. In addition, RL of Tb-1–TOPO has an extremely narrow full width at half maximum and an excellent linear response to the X-ray dose rate. The detection limit is calculated to be 0.146 μGy s −1 , which is 38 times lower than typical medical imaging doses. Triplet-enhanced lanthanide RL provides new ideas for replacing scintillators that require high temperature synthesis processes such as inorganic phosphors and ceramics, and provides a new alternative scintillator material for flexible X-ray monitoring, bioimaging, radiotherapy, and other applications.
Lei-Tao Sha,Qiang Wu,Yi-Fan Zhang,Wei-Jia Wang,Fei Wu,Qing-Gang Huang,Ze-Yi Yan
The hydrophobic deep eutectic solvents (HDES) with low viscosity, density and environmental friendliness have been prepared and characterized based on trioctylphosphine oxide (TOPO) and N,N -dihexyl succinamic acid (DHSCA), which were used as both extractant and organic phase for highly efficient removal of radioactive elements of U(VI) and Th(IV) from rare earth (RE) leaching solution. The extraction efficiency of U(VI) and Th(IV) exceeded 99 % by a single stage extraction. Benefiting from the blocking effect of hydrogen bonding on P = O and the good affinity of DHSCA and TOPO for actinides, the present HDES exhibited the excellent extraction selectivity for U(VI) and Th(IV) over Fe(III), Al(III), Mg(II), Ca(II) and RE(III). Even after seven extraction-stripping cycles, the prepared HDES could still effectively remove radioactive U(VI) and Th(IV) from RE leaching solution. The co-extracted U(VI) and Th(IV) was further separated and enriched by two successive stripping steps. Using the slope analysis, 31 P NMR and FT-IR spectra, the stoichiometry of extracted species and the extraction mechanism of HDES to Th(IV) and U(VI) were evaluated. Due to the superior extraction efficiency, excellent environmental compatibility and sustainability, the present approach offers a practical alternative for removal of radioactive elements from rare earth minerals.