Bis(8-hydroxyquinolate-5-sulfonate)zinc intercalated layered double hydroxide and its controllable luminescent properties

摘要

Bis(8-hydroxyquinolate-5-sulfonate)zinc anion (ZQS~(2-)) and dodecyl sulfonate anion (DDS") have been co-intercalated into the layered double hydroxide host (M_nA1 LDH, M~(2+) = Mg, Zn, n = 2, 3) by a hydrothermal co-precipitation method, with samples denoted as DDS-ZQS(x%)/LDH (x stands for the molar percentage content of ZQS with respect to DDS + ZQS). The structure and chemical composition of the resulting compounds were characterized by X-ray diffraction (XRD), FT-IR and elemental analysis. Their films obtained by the solvent evaporation method have a well-defined c-orientation confirmed by XRD and scanning electron microscopy (SEM). Thermogravimetry and differential thermal analysis (TG-DTA) results elucidate that the thermal stability of ZQS is enhanced upon co-intercalation. The fluorescent studies show that the luminous behavior (wavelength, intensity, lifetime and quantum yield) of ZQS is correlated with the fluorophore content and can be modulated by controlling the host-guest and guest-guest interaction through changing the ratio of DDS to ZQS, metal species and positive charge density of the LDH host layer. DDS-ZQS(5%)/Mg2Al LDH exhibits the optimal luminous intensity and the longest lifetime among the DDS-ZQS(x%)/Mg2Al LDH samples.