A. Divya

Synthesis of silver nanoparticles by soft chemical method: Effect of reducing agent concentration

Silver nanoparticles have successfully synthesized by using tri-sodium citrate as reducing agent and Polyvinyl alcohol (PVA) as capping agent and demonstrated the effect of reducing agent concentration on size variation. Broadened XRD peaks confirmed the formation of nanosized silver nanoparticles with face centred cubic structure and is consistent with FESEM studies. Further XRD results confirmed the decrease of mean particle size with increase of reducing agent concentration. FESEM images illustrate the formation of spherical silver nanoparticles in nanometre regime. EDAX analysis confirms the presence of elemental silver indicating that silver peak is correctly identified ensuring the absence of impurities in the prepared nanoparticles. UV-Visible absorption studies revealed the blue shift of surface Plasmon resonance (SPR) band owing to decrease of particle size with increase of reducing agent concentration.

Effect of Nd on structural and optical properties of Nd doped ZnO nanoparticles

Polyvinylpyrrolidone capped ZnO and Nd (0.5 and 1 at.%) ZnO nanoparticles have been prepared by chemical co-precipitation method in aqueous media. The as-prepared nanoparticles were subjected to compositional, structural, morphological and photoluminescence studies. EDS confirmed the presence of Nd element in ZnO nanoparticles. X-ray diffraction patterns and TEM studies established that pristine and Nd doped ZnO nanoparticles exhibited wurtzite crystal structure. The average particle size obtained from the XRD and TEM were in good agreement with each other. Photoluminescence studies on Nd doping amplify the defect related emission.

Synthesis and characterization of Gd doped ZnS nanoparticles: Enhanced photoluminescence properties

Pristine ZnS and Gd (6 at. %) doped ZnS nanoparticles have been synthesized by facile chemical co-precipitation method in aqueous media at room temperature using PVP as a surface capping agent. The as-prepared samples were characterized by structural, morphological, chemical composition and photoluminescence studies. X-ray diffraction measurements confirmed that pristine and Gd (6 at.%) doped ZnS nanoparticles exhibited cubic zincblende crystal structure. The average particle size obtained from the XRD and TEM were in good agreement with each other. Energy dispersive spectroscopy (EDS) measurement showed the existence of Gd ion in the Gd-doped ZnS nanoparticles. The PL spectra showed enhanced luminescence intensity with the introduction of Gd into ZnS, while the emission wavelength was slightly shifted to higher wavelength side.