Kieu Giang Lam Thi, Trejgis Karolina, Marciniak Łukasz, Opalińska Agnieszka, Koltsov Iwona E, Łojkowski Witold
Institute of Materials Science, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Cau Giay Hanoi Viet Nam
Graduate University of Science and Technology, Vietnam Academy of Science and Technology 18, Hoang Quoc Viet Cau Giay Hanoi Viet Nam.
RSC Adv. 2022 Apr 29;12(21):13065-13073. doi: 10.1039/d2ra01759h. eCollection 2022 Apr 28.
In the present work, nanothermometers based on amorphous zirconium metal-organic frameworks co-doped with rare-earth ions (YZ-BDC:Eu,Tb nanothermometers) with sizes of about 10-30 nm were successfully synthesized a microwave-assisted hydrothermal method at 120 °C for 15 min. The determined BET surfaces area, total pore volume and average pore diameter were ∼530 m g, 0.45 cm g and 3.4 nm, respectively. Based on Fourier transform infrared spectroscopy (FTIR) and simultaneous thermal analysis (STA) results, the formation process of carboxylic acid salts and the molecular formula of the samples have been proposed. The thermometric properties of Zr-BDC:Eu,Tb nanothermometers and their Y ion co-doped counterparts (YZ-BDC:Eu,Tb) measured in the 133-573 K temperature range were compared. Moreover, the temperature-dependent CIE(x, y) chromaticity coordinates and emission color of the samples were also determined. As the temperature increased from 133 to 573 K, the emission color of Zr-BDC:Eu,Tb nanothermometers without the presence of Y ions changed from orange to red, while for YZ-BDC:Eu,Tb nanothermometers, the emission color changed from yellow to orange, due to the strong effect of the presence of Y ions on the luminescence intensity of Eu and Tb ions. The maximum relative sensitivity ( ) in both materials was close to 0.5%/K, however, the temperature range of their occurrence was significantly shifted toward higher temperatures due to doping with Y ions. The obtained results showed that doping with Y ions not only enables the modulation of the useful temperature range with high relative sensitivity, but also provides improved thermal stability.
在本工作中，通过微波辅助水热法在120℃下反应15分钟，成功合成了尺寸约为10 - 30nm的、共掺杂稀土离子的非晶态锆基金属有机框架纳米温度计（YZ-BDC:Eu,Tb纳米温度计）。测定的BET表面积、总孔体积和平均孔径分别约为530 m²/g、0.45 cm³/g和3.4 nm。基于傅里叶变换红外光谱（FTIR）和同步热分析（STA）结果，提出了羧酸盐的形成过程和样品的分子式。比较了Zr-BDC:Eu,Tb纳米温度计及其Y离子共掺杂对应物（YZ-BDC:Eu,Tb）在133 - 573K温度范围内的测温性能。此外，还测定了样品的温度依赖性CIE(x, y)色度坐标和发射颜色。随着温度从133K升高到573K，不存在Y离子的Zr-BDC:Eu,Tb纳米温度计的发射颜色从橙色变为红色，而对于YZ-BDC:Eu,Tb纳米温度计，由于Y离子的存在对Eu和Tb离子发光强度的强烈影响，发射颜色从黄色变为橙色。两种材料中的最大相对灵敏度（ ）接近0.5%/K，然而，由于Y离子掺杂，其出现的温度范围显著向更高温度偏移。所得结果表明，Y离子掺杂不仅能够在高相对灵敏度下调节有用温度范围，还能提供更高的热稳定性。
