Simple Preparation of LaPO4:Ce, Tb Phosphors by an Ionic-Liquid-Driven Supported Liquid Membrane System

Abstract

In this work, LaPO4:Ce, Tb phosphors were prepared by firing a LaPO4:Ce, Tb precipitate using an ionic-liquid-driven supported liquid membrane system. The entire system consisted of three parts: a mixed rare earth ion supply phase, a phosphate supply phase, and an ionic-liquid-driven supporting liquid membrane phase. This method showed the advantages of a high flux, high efficiency, and more controllable reaction process. The release rate of PO43− from the liquid film under different types of ionic liquid, the ratio of the rare earth ions in the precursor mixture, and the structure, morphology, and photoluminescence properties of LaPO4:Ce, Tb were investigated by inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction, Raman spectra, scanning electron microscopy, and photoluminescence emission spectra methods. The results showed that a pure phase of lanthanum orthophosphate with a monoclinic structure can be formed. Due to differences in the anions in the rare earth supply phase, the prepared phosphors showed micro-spherical (when using rare earth sulfate as the raw material) and nanoscale stone-shape (when using rare earth nitrate as the raw material) morphologies. Moreover, the phosphors prepared by this method had good luminescent properties, reaching a maximum emission intensity under 277 nm excitation with a predominant green emission at 543 nm which corresponded to the 5D4-7F5 transition of Tb3+.

Room-Temperature, Ultrafast, and Aqueous-Phase Synthesis of Ultrasmall LaPO4:Ce3+, Tb3+ Nanoparticles with a Photoluminescence Quantum Yield of 74%

“…6−11 It has been widely reported that the energy transfer process from Ce 3+ to Tb 3+ can burst the PLQY of LaPO 4 :Ce 3+ , Tb 3+ phosphors. 6−11 In recent years, the synthetic methods of LaPO 4 :Ce 3+ , Tb 3+ phosphors have been well established and extensively reported, including high-temperature solid-state reaction, 6,7 hydrothermal method, 12−14 solvothermal method, 15−17 spray pyrolysis, 18 electrostatic spinning, 19 chemical precipitation, 20,21 microwave-assisted reaction, 22−24 sol−gel method, 25,26 ionic liquidbased approach, 27 ultrasonic irradiation methods, 28 and hotinjection approach. 29−32 However, highly luminescent La-PO 4 :Ce 3+ , Tb 3+ phosphors were usually prepared by a high-temperature solid-state reaction, which requires the calcination temperature beyond 1000 °C for several hours.…”

“…In recent years, the synthetic methods of LaPO 4 :Ce 3+ , Tb 3+ phosphors have been well established and extensively reported, including high-temperature solid-state reaction, , hydrothermal method, − solvothermal method, − spray pyrolysis, electrostatic spinning, chemical precipitation, , microwave-assisted reaction, − sol–gel method, , ionic liquid-based approach, ultrasonic irradiation methods, and hot-injection approach. − However, highly luminescent LaPO 4 :Ce 3+ , Tb 3+ phosphors were usually prepared by a high-temperature solid-state reaction, which requires the calcination temperature beyond 1000 °C for several hours. , For the bulk LaPO 4 :Ce 3+ , Tb 3+ phosphor, the PLQY of Tb 3+ emission can be as high as 86%. In contrast, the PLQYs of LaPO 4 :Ce 3+ , Tb 3+ nanocrystals are significantly lower than that of the corresponding bulk phosphor. − Recently, LaPO 4 :Ce 3+ , Tb 3+ nanocrystals with a Tb 3+ PLQY of 70% have been synthesized by a microwave-assisted approach . These nanocrystals with a size of 6–10 nm exhibit a prominent Ce 3+ ion emission and have a chemical composition of La 0.4 PO 4 :Ce 0.45 3+ , Tb 0.15 3+ , which are exactly the same as the corresponding bulk phosphor .…”

The Physical Chemistry and Chemical Physics (PCCP) Section of the International Journal of Molecular Sciences in Its Publications: The First 300 Thematic Articles in the First 3 Years

“…This thematic area is associated with articles [ 12 , 15 , 20 , 21 , 26 , 50 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 ], of which there are a total of 50. In contrast to the areas already discussed above, articles of all four types are presented here ( Table 5 ), although, here, too, the Original constitutes a clear majority over the other 3 types of articles.…”

“…In contrast to the areas already discussed above, articles of all four types are presented here ( Table 5 ), although, here, too, the Original constitutes a clear majority over the other 3 types of articles. The dominant feature of this thematic area was articles devoted to cell membranes, in general, and their electrochemistry, in particular; articles [ 26 , 50 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 92 , 93 , 95 , 99 , 100 ] are devoted to this specific topic. In this connection, it is worth noting that this “membrane topic” turned out to be, generally, the most popular in comparison with all the others presented in the PCCP Section of the IJMS , within the array of 300 articles we are considering.…”

Ion and Molecule Transport in Membrane Systems

“…The analysis of interesting and diverse applications of artificial membranes is reported in references [ 16 , 17 , 18 , 19 ]. An ionic liquid-driven supported liquid membrane system was applied by J. Li et al [ 16 ] for preparing a special kind of phosphors, which were characterized by good luminescent properties. The team of L. Bazinet for the first time realized simultaneous separation of peptides from salmon protein hydrolysate by three ultrafiltration membranes stacked in an electrodialysis system [ 17 ].…”