Preparation, luminescence and highly sensitive oxalate sensor of porous EuBO3 microwafers

Abstract In this work, uniform porous EuBO3 microwafers were obtained by calcining Eu-based coordination polymer (CP) which were synthesized by a facile solvothermal method without any mineralizer addition. The products were fully characterized by X-ray diffraction (XRD), energy dispersive spectrometer (EDS), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and photoluminescence (PL). The diameter and thickness of the EuBO3 microwafers are approximately 3 μm and 0.6 μm, respectively. Under λex = 394 nm, photoluminescence spectrum of EuBO3 is observed in 570–720 nm, which are attributed to the 5D0-7FJ (J = 0, 1, 2, 3, 4) transitions. Further investigations reveal that the porous EuBO3 microwafer is a highly selective and sensitive oxalate sensor, with the limit of detection (LOD) as low as 1 × 10−8 M. Overall, this study provide a convenient route for the synthesis of rare earth borate. To the best of our knowledge, it is the first time to demonstrate that EuBO3 is a viable probe for sensing oxalate.