Low-temperature molten salt synthesis and luminescence properties of Eu(III)-based coordination polymer nanosheets

In this work, Eu(III)-based coordination polymer (EuCP) nanosheets were successfully synthesized using tetrabutylammonium bromide (TBAB) as low-temperature molten salt (LMS), terephthalic acid (PTA) and pyromellitic acid (PMA) as organic building blocks at 160 °C. X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetry and differential thermal analysis (TG–DTA) were used to characterize the obtained products. Results show that the nanosheets have an average size of 200 nm and a thickness of about 50 nm. The effect of reaction temperature, reaction time and molar ratio of Eu³⁺/PTA/PMA on the preparation was investigated. It turns out that all of them have great effect on morphology and size of the final product. When excited with 315 nm, strong emission centering at 617 nm is realized. Importantly, this synthetic methodology may offer a new alternative in the preparation of rare earth nanomaterials.