Color-tunable luminescent Ln3+ composite as self-referencing and ratiometric sensor for low-level water detection in ethanol. (November 2017)

• Record Type: Journal Article
• Authors: Wang, Tianren; Liu, Meiqi; Wang, Yige
• Is Part Of: Materials research bulletin. Volume 95(2017)
• Page Start: 426
• Page End: 430
• Publication Date: 2017-11
• Subjects: Lanthanide -- Hctpy -- Tunable luminescence -- Energy transfer -- Low-level water detection; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2017.08.022
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: A new color-tunable luminescent Ln 3+ (Ln = Eu, Tb or Eu and Tb in different molar ratio) composite was prepared through a simple method, which can be applied as self-referencing and ratiometric sensor for detecting low-level water content (0.01-0.5 vol%) in ethanol. Highlights: A novel Ln 3+ (Ln = Eu, Tb or Eu and Tb in different molar ratio) complex with tunable luminescence from red to green was prepared through a simple procedure. The luminescence color of the Eu/Tb co-doped complex can be tuned by water through the luminescence quenching mechanism as well as the variation of energy transfer efficiency from Tb 3+ to Eu 3+ . The complex with Eu 3+ :Tb 3+ = 1:1 can be applied as self-referencing and ratiometric luminescent sensor for detecting low-content water (0.01–0.5 vol%) in ethanol. Abstract: Developing simple, fast and sensitive detection of low-level water in organic solvents is in high demand for academic and industrial applications. In this paper, a novel color-tunable lanthanide composite has been prepared by simply mixing 2, 2':6', 2"-terpyridine-4'-carboxylic acid (Hctpy) and Ln 3+ with a molar ratio of 3:1 in absolute ethanol at room temperature, in which the Ln 3+ ions are mainly coordinated with carboxyl moieties rather than with terpyridine moieties of Hctpy. In addition, the emission colors of the composite can also be tuned by water, ascribed to the luminescence quenching mechanism and the variation of Tb-to-Eu energy transfer efficiency. Based on these properties, a self-referencing and ratiometric luminescent water detector with the Eu/Tb molar ratio of 1:1 has been developed, showing proportional relationship between the intensity ratio of 5 D0 → 7 F2 transition of Eu 3+ to 5 D4 → 7 F5 transition of Tb 3+ (IEu /ITb ) and the water concentration (0.01–0.5 vol%) in ethanol.