Synthesis and characterization of cobalt and copper sulfide nanoparticles with reproducible stoichiometry using sulfur containing single-source precursors

Abstract

Complexes of alkyldithiocarbamate and thiuram have been extensively explored for various applications in the medical field. Thiuram and dithiocarbamate ligands were used to prepared complexes of cobalt and copper. The high abundance of sulfur in these ligands has resulted to be the preferred complexes for the synthesis of metal sulfide nanoparticles. All the prepared complexes were characterized using techniques such as IR and 1HNMR spectroscopy, elemental analysis, and thermogravimetric analysis. All the spectra data obtained were consistent with the coordination of the ligands through sulfur atom to the metal ion. The thermogravimetric analysis of all complexes decomposed to form metal sulfide, which really confirmed that all the complexes could be used to metal sulfide nanoparticles. All the prepared complexes were used to synthesize MxSy nanoparticles. The metal sulfide nanoparticles were successful prepared by thermal decomposition of the single-source precursor in hexadecylamine solution. The reaction parameter such as the concentration (1.0, 0.5, 0.25 and 0.125 g), reaction temperature (80, 130, 200, 250 °C) and the time (5, 10, 15, 20, 25 and 30) of the reactionwere varied to see their effect on the preparation of the nanoparticles. The prepared metal sulfide nanoparticles were characterized using techniques such as UV spectroscopy, photoluminescence spectroscopy, X-ray diffraction analysis and transmission electron microscopy. The concentration was found to have a profound effect in size and shape of the prepared nanoparticles. The nanoparticles prepared at various concentrations were dominated by sphere with an average size of 2-30 nm. The XRD pattern confirmed that the composition is not affected by the temperature. Thetemperature has a dramatic effect in size, shape and the stoichiometry of the reaction. This was confirmed by an increase in size as the temperature was increased, with the exception of cobalt sulfide nanoparticles that decrease in size while temperature was increase. The XRD pattern showed different composition as the temperature was varied. Time of the reaction was found to affect the particles size of the nanoparticle. The sizes of the nanoparticles were increase as the time of the reaction was prolonged.