Study on white-light-emitting materials of lanthanide metal-organic frameworks based on ligand of 1,3,5-benzenetricarboxylate

Two kinds of Dy(III) MOFs of Dy-BTC and MxDy1-x-BTC (M = Gd3+, Zn2+, Ni2+, Mg2+) were successfully synthesized under similar solvothermal reaction conditions. The specific structures of these were analyzed by power XRD and infrared spectrum. Their chemical formulas were ensured by power XRD combined with elemental analysis, their heat stability were tested by TG and their photoluminescence properties were also investigated. The results are that the present and proportion of M shows a direct influence not only on crystal structure but on luminescence property and energy transfer from H3BTC to Dy3+ is not complete so that luminous intensity is weak in Dy-BTC. However, compound MxDy1-x-BTC has obvious sensitizing effect on fluorescence intensity of Dy3+. Fluorescence intensity of Dy3+ is the highest in MOFs mixed with Zn2+. After further experiment about ZnxDy1-x-BTC, the fluorescence intensity increases and then decreases with increase of proportion of Dy3+ in the complex at λex = 270 nm, and the fluorescence intensity reaches the top when proportion of Dy3+ and Zn2+ is 0.0625:0.9325. Meanwhile, Zn0.9325Dy0.0625-BTC shows ideal CIE coordinates of (0.3339, 0.3633), which are close to the international pure white-light CIE coordinates of (0.3333, 0.3333). Therefore, compound MxDy1-x-BTC is a promising material in application of white LEDs.