Single-phase white light material and antibiotic detection of lanthanide metal–organic frameworks

Abstract

WLEDs have been widely used in lighting and display equipment due to their energy-saving and environment-friendly advantages, but it is still a great challenge to construct high-quality single-phase white light materials for the preparation of WLEDs. In this work, three Ln–MOFs (HNU-82–84) with the same structure were synthesized by assembling rare earth ions (Tb³⁺, Eu³⁺, La³⁺) and 4,4′,4′′-nitrilotribenzoic acid (H₃TCA) ligands. The structure and optical properties of the three compounds were investigated. Under the ultraviolet lamp, HNU-82–84 displays green light, red light, and blue light emission, respectively. Based on the RGB principle, aiming at the single-phase white material, the proportion of adding rare earth ions is reasonably adjusted to design and synthesize the Ln–MOF (Eu_0.015Tb_0.037La_0.148-TCA) with CIE chromaticity coordinates of (0.319, 0.344). In addition, the WLED was prepared by Eu_0.015Tb_0.037La_0.148-TCA and commercial LED lamps. Furthermore, HNU-82 has strong fluorescence emission and good water stability and can be used to detect nitrofurazone (NZF) and nitrofurantoin (NFT). The concentrations of the aqueous solutions of NZF and NFT had a well correlated linear relationship with the fluorescence quenching effect of HNU-82, and the detection limits were 6.60 × 10⁻⁷ mol L⁻¹ and 4.62 × 10⁻⁷ mol L⁻¹, respectively. Hence, HNU-82 also has potential as a fluorescent sensor for the detection of NZF and NFT in the aquatic environment.