Study on structure and photoluminescence of Tb-doped ZnAl-NO3 layered double hydroxides prepared by co-precipitation

Tb-doped ZnAl-NO3 layered double hydroxides (LDHs), with Zn2+/(Al3+-FTb3+) molar ratio of 13, 2.0, 3.0 and 4.0, were prepared by co-precipitation and investigated by various characterization. The compositional analysis reveals that the chemical composition of the Tb-doped LDHs is in agreement with that of the raw materials. XRD patterns show that all the samples present a single phase corresponding to hexagonal structure of LDHs. Fourier Transform Infrared spectroscopy (FT-IR) exhibits characteristic bands attributed to OH and NOT groups as well as metal oxygen vibration. Photoluminescence suggests the characteristic emissions ascribed to 5D4-7Fj (J = 3, 4, 5, 6) transitions, indicating the permission of D-5(4)-(7)FJ transitions for Tb3+ ions in the ZnAl NO(3-)LDHs system. The ratio of (D-5(4)-F-7(5))/(D-5(4)-7F(6)) emission intensity, which is highly hypersensitive to TIP+ surroundings, increases with increasing molar ratio of Zn2+/(Al3+-FTb3+). These results confirm the formation of the Tb-doped ZnAl NO3 layered double hydroxides with luminescent property. (C) 2016 Published by Elsevier B.V.