abstract
The synthesis of dual-emission nanocomposite materials has emerged as an excellent strategy for designing new and advanced luminescent ratiometric thermometers. In the present work, a dual-emission nanocomposite material based on carbon dots (CDots), with chitosan as the precursor, and Europium-Organic Framework (CDots/EuBDC) was prepared, through ultrasonic synthesis, and applied as a ratiometric thermometer. Whereas the as-synthesized nanocomposite maintains the crystalline structure of EuBDC, its thermal stability increases and the surface area decreases due to the CDots incorporation. The ratio of the CDots/EuBDC emission intensities (I-CDots/I-Eu) is temperature-dependent in the 293 to 348 K range, in which the intensity of the Eu3+ 5D0 -> F-7(2) transition works as a reference signal. The CDots/EuBDC luminescent thermometer shows a maximum relative thermal sensitivity of 1.58% K-1 at 293 K and a colorimetric temperature response with (x, y) CIE color coordinates ranging from blue (0.36, 0.27), at 293 K, to orange (0.43, 0.30), at 343 K.
keywords
METAL-ORGANIC FRAMEWORKS; CARBON DOTS; EMISSION; LIFETIME; PHOTOLUMINESCENCE; COORDINATION; NANODOTS; SENSORS; NANOTHERMOMETRY; COMPOSITES
subject category
Materials Science; Physics
authors
da Silva, KRM; Calado, CMS; dos Santos, TV; Sales, TD; Viana, RD; Silva, UR; Ferreira, RAS; Carlos, LD; Barbosa, CDAES
our authors
Luís Carlos
Full professor
Maria Rute de Amorim e Sá Ferreira André
Full professorProjects
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
The authors thank the staff of the Catalysis and Chemical Reactivity Group (GCaR-IQB-UFAL) for the materials and for providing the infrastructure to perform the experiments. The Optics and Nanoscopy Group (GON-IF-UFAL), Group of Nano-Photonics and Imaging (GNFI) and Earth Rare Laboratory - BSTR (dQF-UFPE) performed the optical measurements. This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC). This work was also supported by CAPES, FINEP, and FAPEAL. KRMS, CMSC, TVS, and RSV express their appreciation for fellowships granted by CAPES and CNPq. We gratefully acknowledge PNPD/CAPES program for a scholarship (grant no. 88887.335315/2019-00). We also acknowledge the financial support from CNPq through the grants scholarship in Research Productivity 2 under the Nr.310412/2018-8 (U.R.)