Facile synthesis of rare earth-doped CeF3 two-dimensional nanosheets and their application in ratiometric luminescence temperature sensing

Abstract

Discovery of new morphological and structural materials is significant but remains challenging. In this work, rare earth-doped CeF₃ two-dimensional (2D) nanosheets were successfully synthesized using a facile and effective solvothermal method. By changing the amount of water in the solvent and the doping amount of rare earth ions, the morphology of CeF₃ is significantly affected, but the hexagonal phase structure is always maintained. Under excitation at 254 nm, CeF₃:20% Gd, 30% Tb 2D nanosheets emit bright green light, but the luminescence color changes to red when some of the Tb³⁺ ions are replaced by Eu³⁺ ions due to the efficient energy transfer from Tb³⁺ to Eu³⁺ ions. Moreover, the temperature-dependent luminescence properties of CeF₃:20% Gd, 25% Tb, 5% Eu prove that it can be used as a ratiometric luminescent thermometer with an absolute sensitivity of 1.54% K⁻¹ and a maximum relative sensitivity of 4.56% K⁻¹ at 373 K. This study enriches the treasure trove of new materials and paves the way for future applications of CeF₃-based luminescent materials in the field of temperature sensing.