No abstract

Green synthesis of c-Gd 2 S 3 nanoparticles was carried out using low-temperature hydrothermal route in autoclave. A 1:1 mixture of ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate, ([EMIM][EtSO4]), and water was used as a solvent. Synthesized nanoparticles were characterized by x-ray powder diffraction (XRPD), scanning electron microscopy (SEM), UV-visible spectroscopy (UV-vis), particle size by dynamic light scattering (DLS) technique, and photoluminescence (PL) studies. XRPD suggests cubic Th 3 P 4 -type structure for obtained Gd 2 S 3 nanoparticles. The size of synthesized nanoparticles is about 86 nm. Optical band gap for these nanoparticles estimated from electronic spectrum is 2.95 eV which shows blue shift from values reported for bulk Gd 2 S 3 due to pronounced quantum mechanical effect. These nanoparticles show sharp emission peak at 385 nm and a broad shoulder at 475 nm when excited at 260 nm.

Cadmium sulphide (CdS) nanoparticles doped with Co 2? and co-doped with Co 2? and rare earth metallic ions have been prepared by co-precipitation method. The synthesized nanoparticles have been characterized by X-ray powder diffraction studies, energy dispersive X-ray analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, particle size by dynamic light scattering and photoluminescence studies. The X-ray diffraction results indicate that CdS nanoparticles can be co-doped with cobalt and rare earth metallic ions without altering XRD pattern. The particle size calculated from XRD results is in range of 40-50 nm. SEM results show that the synthesized particles are spherical in shape and TEM results reveal that synthesized particles have a very small size nearing to Bohr radius for bulk CdS. Absorption spectra of all the samples show strong blue shift from bulk CdS. Interesting luminescence characteristics have been observed for co-doped CdS nanoparticles at room temperature. The relative fluorescence intensity of co-doped samples is significantly higher than that of undoped and Co 2? doped CdS nanoparticles.

Cadmium sulphide (CdS) nanoparticles doped with Cu 2+ and co-doped with rare earth metallic ions (Ln 3+ ) have been synthesized by co-precipitation method. The synthesized nanoparticles were characterized by powder X-ray diffraction studies (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size by dynamic light scattering (DLS), UV-visible spectroscopy (UV), and photoluminescence (PL) studies. It is observed that CdS nanoparticles can be co-doped with copper and rare earth metallic ions without altering XRD pattern as indicated by X-ray diffraction results. SEM and TEM results show that synthesized particles have spherical aggregation. Absorption spectra of all the samples show strong blue shift from bulk CdS. Interesting luminescence pattern with enhanced intensity has been observed for co-doped CdS nanoparticles at room temperature.

Pure and Gd doped Zinc Oxide (ZnO) nanoparticles were synthesized by sonochemical method using different surfactants (PVP/CTAB). The nanoparticles were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), particle size analysis by DLS technique and UV-Visible spectroscopy. The effect of Gd doping and nature of surfactants on crystallite size, morphology and band gap of ZnO nanoparticles have been investigated. In addition to this, the effect of nature of surfactant on amount of dopant inserted in the ZnO lattice was also studied.