Mixed-LnMOFs with tunable color and white light emission together with multi-functional fluorescence detection

Abstract A series of mixed lanthanide metal-organic frameworks: [(EuxTb1-x)2(TDC)3(CH3OH)2·(CH3OH)] ((abbreviated as EuxTb1-x-MOFs, x = 0.5, 0.067, 0.05, 0.01, 0.00833, 0.00667, 0.005, x represents the molar ratio of Eu in the total amounts), H2TDC = 2, 5-thiophenedicarboxylic acid) have been prepared under solvothermal condition by adjusting the molar ratio of Eu3+ to Tb3+ ions. The emission colors of EuxTb1-x-MOFs have been tuned by controlling the molar ratio of Eu3+/Tb3+ and changing the excitation wavelength. Fortunately, a white light-emitting material Eu0.00667Tb0.99333-MOF has been obtained at the excitation wavelength of 350 nm. The CIE coordinate of (0.3333, 0.3394) is very close to the standardized coordinate for pure white light (0.3333, 0.3333). Furthermore, the fluorescence sensing performance of Eu0.00667Tb0.99333-MOF for hazardous phenolic compounds and physiological temperature were tested upon excitation at 320 nm. The results reveal that Eu0.00667Tb0.99333-MOF can be used as a multi-target sensor for selective sensing β-naphthol and physiological temperature from 288 to 353 K with good sensing reproducibility.