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Abstract: The amorphous MoS2 nanoparticles have been synthesized by a simple oxidation–reduction reaction in an aqueous solution. A series of products with different morphologies, such as MoS2 nanospheres, inorganic fullerene-like nanospheres, nanorods and Mo bended rods, can be obtained by annealing the amorphous MoS2 nanoparticles under N2 atmosphere under 400–1200°C. These products have been characterized by X-ray diffraction, field emission scanning electronic microscopy, transmission electron microscopy and high-resolution transmission electron microscopy in detail. The possible transformation mechanism for the structure has been discussed based on the experimental results. In addition, the optical properties of IF-MoS2 have also been performed by UV–vis absorption spectroscopy. [Copyright &y& Elsevier]

Abstract: W/WS2 inorganic fullerene-like (IF) nanoparticles with core–shell structure are synthesized by the reaction of tungsten nanospheres and sulfur at relatively low temperatures (380–600°C) under hydrogen atmosphere, in which tungsten nanospheres were prepared by wire electrical explosion method. Images of transmission electron microscopy and high-resolution transmission electron microscopy show that the composite particles are of core–shell structure with spherical shape and the shell thickness is about 10nm. X-ray powder diffraction results indicate that the interlayer spacing of IF-WS2 shell decreases and approaches that of 2H-WS2 with increasing annealing temperatures, representing an expansion of 3.3–1.6%. A mechanism of IF-WS2 formation via sulfur diffusion into fullerene nanoparticles is discussed. Thermal analysis shows that the nanoparticles obtained at different temperatures exhibit similar thermal stability and the onset temperature of oxidization is about 410°C. Encapsulating hard tungsten core into IF-WS2 and the spherical shape of the core–shell structures may enhance their performance in tribological applications. [Copyright &y& Elsevier]

Abstract: TiO2/SrFe12O19 composite nanoparticles with core-shell structure have been obtained. The core SrFe12O19 nanoparticles were synthesized by citrate precursor technique with Fe/Sr ratio of 10.8, and then the shell TiO2 nanocrystals were derived via sol–gel technology. The presence of a small amount of polyethyleneimine (PEI) on the surface of the strontium ferrite nanoparticles facilitates this coating process. The morphology, crystalline structure, particle size and size distribution of TiO2/SrFe12O19 composite nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and 3000HSA analyzer (MALVERN), respectively. Energy-dispersive spectroscopy (EDS) was utilized for the elemental analysis of the products. The as-prepared composite particles can be utilized as a magnetic photocatalyst, which can be fluidized and recovered by an applied magnetic field enhancing both separating and mixing efficiency for recyclable fluids. Magnetic properties and photocatalytic activities of these powders have been evaluated. The result of the experiments shows that the saturation magnetizations of titania-coated SrFe12O19 nanoparticles decrease as increasing the thickness of the titania coating, while the coercivity does not show any change after coating. Photocatalytic activities of these powders increase with increasing the thickness of TiO2 coating layer. [Copyright &y& Elsevier]

Abstract: A core-shell structure TiO2/BaFe12O19 composite nanoparticles that can photodegrade organic pollutants in the dispersion system effectively and can be recycled easily by a magnetic field is reported in this paper. The obtained samples were characterized by energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The TiO2/BaFe12O19 magnetic photocatalyst is composed of two parts: (1) TiO2 shell used for photocatalysis and (2) BaFe12O19 core for separation by the magnetic field. The photocatalytic activity of the as-prepared magnetic photocatalyst increased with increasing the thickness of TiO2 coating layer. On the other hand, the saturation magnetizations of titania-coated BaFe12O19 nanoparticles decreased with increasing thickness of the titania coating, while the coercivity does not show any change after coating. [Copyright &y& Elsevier]