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Nanocomposites containing magnetic nanoparticles embedded in a polymer matrix with good thermal stability (up to 200°C) are technologically important. We report an environmentally benign solid–solid approach for synthesis of cobalt sulfide and its nanocomposite using a thermally stable matrix of polyphenylene sulfide. Physicochemical characterizations reveal the formation of nanoclusters of the hexagonal phase CoS. Even though bulk CoS is nonmagnetic, magnetization studies exhibit anomalous magnetic behavior for phase-pure nanoscale CoS and its nanocomposites.

A highly crystalline ZnO nano pencils/rods were successfully synthesized via low cost and template free solvothermal method. The reaction was carried out at 200 C for 2, 5 and 12 h respectively. The reaction time enhances the photoluminescent properties of ZnO, mainly the intensity of green emission band increased. X-ray diffraction revealed the formed products have a wurtzite structure. The morphology and microstructure analyses of ZnO nano pencils/rods were performed by field emission scanning electron microscopy and transmission electron microscopy. The ZnO nanorods are about 20 to 70 nm in width and length varies from nm to sub-micron size. TEM confirms formation of pencil and rod shaped ZnO nanostructures. ZnO synthesized using different reaction time showed UV-Visible absorbance at 372 nm. Photoluminescence measurement showed UV emission peak and broad yellow–green emission peak centered at 390 and 500 nm respectively. Photocatalytic activity of synthesized ZnO was evaluated by following the degradation of aqueous methylene blue dye. Change in the photocatalytic activity was observed with change in reaction time of ZnO synthesis. ZnO prepared at 2 h of reaction time showed apparent rate constant (Kapp) of 8.8×10−2 min−1 for MB degradation.

At present, there is considerable interest in polymer-metal chalcogenides/oxides based nano-composites on account of their tunable optical, magnetic, electronic and catalytic properties. Here in, we report a simple single step approach for the in-situ synthesis of combined cobalt sulphide/cobalt oxide in polyphenylenesulphide (PPS) polymer matrix. We have illustrated the suitability of this methodology by reacting commonly available cobalt precursors with engineering thermoplastic, PPS. The cobalt precursor was homogeneously mixed with PPS in the molar ratios of 1:1, 1:5, 1:10, 1:15, respectively, followed by heating the mixtures obtained at the melting temperature of the polymer (285?C) for six hours. The resultant products were characterized by X-ray Diffractometry (XRD), Field-Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscope (HRTEM), Diffuse Reflectance Spectroscopy (DRS) technique and Fourier Transformation Infra red Spectroscopy (FTIR). Formation of mixed phases viz., sulphide and oxide of cobalt within modified PPS matrix was confirmed by XRD. The resultant nanoparticles of cobalt sulphide and cobalt oxide embedded in the PPS matrix showed crooked and chunk morphology. The optical properties of the resultant nanocomposites indicate the shift in the absorption hump due to nanoscale size effect.