[Preparation and spectroscopy properties of Eu2 (CA)3 (phen)2 doped Eu3+/TiO2 nano-powders]

The 1% Eu3+ doped Eu3+ /TiO2 nano-powders were prepared via sol-gel method by using Eu(NO3)3 and Eu2 (CA)3 (phen)2 (CA: camphoric acid; phen: 1, 10-phenanthroline) as precursors respectively, and the samples were characterized by thermal analyses (TG-DTA), X-ray powder diffraction(XRD), scanning electron microscope(SEM), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectra and fluorescence spectra for their microstructure, morphology and spectroscopy properties. The results of TG-DTA and XRD indicate that the increasing trend of particle size and the conversion temperature of crystalline phase of the as prepared samples was restrained when using organic complexes Eu2(CA)3 (phen)2 as the do pant. The particle size was decreased from 9 to 7 nm, and the name powders were still anatase TiO2 when the calcination temperature was increased up to 500 degrees C. The absorption peak at about 370 nm in UV-Vis spectra was red-shifted when doping with organic complexes Eu2 (CA)3 (phen)2, namely the doped TiO2 nano powders have the ability of visible light responding. The characteristic absorption peaks of organic complex did not appear in FTIR spectrum, indicating that the Eu3+ has little impact on the formation process of TiO2 crystal when using Eu2(CA)3 (phen)2 as precursor. The result of fluorescence spectrum indicates that the characteristic transition of Eu3+ at 578 nm (corresponding to (5)D0---(7)F0), 590 nm((5)D0-(7)F1) and 612 nm ((5)D0-(7)F2) appeared in both samples, in which the peak at 612 nm was the characteristic red transmutation peak. When doping Eu3+ with the same content, the nano-powders using Eu2 (CA)3 (phen)2 as precursor obtain higher luminescence intensity. Therefore, by using a simple approach, the authors prepared the light-emitting rare earth inorganic nano-powders with better luminescence property and high stability, and such inorganic nano-powders might have potential applications in many fields.