Dual-Emitting UiO-66(Zr&Eu) Metal-Organic Framework Films for Ratiometric Temperature Sensing

A novel dual-emitting metal-organic framework based on Zr and Eu, named as UiO-66(Zr&Eu), was built using a clever strategy based on secondary building units. With the use of polymers, the obtained UiO-66(Zr&Eu) was subsequently deposited as thin films that can be utilized as smart thermometers. The UiO-66(Zr&Eu) polymer films can be used for the detection of temperature changes in the range of 237-337 K due to the energy transfer between the lanthanide ions (Eu in clusters) and the luminescent ligands, and the relative sensitivity reaches 4.26% K^-1 at 337 K. Moreover, the sensitivity can be improved to 19.67% K^-1 by changing the film thickness. In addition, the temperature-sensing performance of the films is superior to that of the powders, and the sensor can be reused 3 times without loss of performance.