Highly colloidal luminescent porous Tb-doped gadolinium oxide nanoparticles: Photophysical and luminescent properties

Abstract

Highly colloidal luminescent Gd2O3:Tb nanoparticles(NPs) were prepared by urea-based homogeneous co-precipitation process. X-ray diffraction pattern (XRD), transmission electron microscopy(TEM), energy dispersive x-ray analysis(EDX), thermogravimetric analysis(TGA), zeta potential, Fourier transform infrared(FTIR), FT-Raman, UV/Visible and photoluminescence spectroscopy to examine the crystallographic, phase purity, shape & size, thermal stability, surface chemistry, optical and photoluminescence properties. XRD results exhibited the single phase, highly pure cubic phase Gd2O3:Tb nanocrystals with an average grain size of 10–20 nm. The Gd2O3:Tb NPs exhibits attractive thermal, optical and luminescent properties for their use in long-term biological studies because of high thermal, photo-stability and strong emission sensitivities in the visible region. Optical features of Gd2O3:Tb NPs were examined in aqueous media and estimated energy band gap on the basis of absorption spectra. An observed strong peak located at 359 cm−1 is assigned to the Fg Raman active mode of cubic phase of nanocrystalline Gd2O3. The luminescence spectra show well dominant green emission transition in between 535–560 nm (5D4→7F5) under monitoring UV light (325 nm). Optically active, aqueous sensitivities, porous surface and strong luminescent NPs as revealed from TEM micrographs could be a promising candidate for future fluorescent biomedical applications.