• R K Swarnkar

Articles written in Bulletin of Materials Science

• Zn/ZnO core/shell nanoparticles synthesized by laser ablation in aqueous environment: Optical and structural characterizations

Zn/ZnO core/shell nanoparticles are synthesized by pulsed laser ablation (PLA) of Zn metal plate in the aqueous environment of sodium dodacyl sulfate (SDS). Solution of nanoparticles is found stable in the colloidal form for a long time, and is characterized by UV-visible absorption, transmission electron microscopy (TEM), photoluminescence (PL) and Raman spectroscopic techniques. UV-visible absorption spectrum has four peaks at 231, 275, 356, and 520 nm, which provides primary information about the synthesis of core-shell and elongated nanoparticles. TEM micrographs reveal that synthesized nanoparticles are monodispersed with three different average sizes and size distributions. Colloidal solution of nanoparticles has significant absorption in the green region, therefore, it absorbs 514.7 nm light of Ar+ laser and emits in the blue region centred at 350 and 375 nm, violet at 457 nm and green at 550 nm regions. Raman shift is observed at 300 cm-1 with PL spectrum, which corresponds to ${}^{3}$𝐸2N and 𝐸3L mode of vibrations of ZnO shell layer. Synthesis mechanism of Zn/ZnO core/shell nanoparticles is discussed.

• Effect of aging on copper nanoparticles synthesized by pulsed laser ablation in water: structural and optical characterizations

Effect of aging on copper nanoparticles synthesized by pulsed laser ablation of copper plate in water was studied. By characterization studies of the aged nanoparticles, it is found that copper nanoparticles converted into Cu@Cu2O nanostructure. The synthesized nanomaterial is characterized with UV-Visible absorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman and photoluminescence (PL) spectroscopic techniques. TEM image shows that the aged nanoparticles get assembled into cactus like structure and are spherical in shape with average diameter 7 nm and dispersion 2 nm. XRD and FTIR spectrum confirm the formation of Cu@Cu2O in the aged sample. Raman spectrum also confirms the presence of Cu2O nanoparticles. PL spectrum of the aged nanoparticles shows a direct allowed transition with bandgap energy of 2.24 eV. The mechanism for synthesis of core-shell nanoparticles and formation of self-assembly of nanoparticles is also discussed.

• # Bulletin of Materials Science

Current Issue
Volume 42 | Issue 6
December 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019