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Chalcostibite copper antimony sulfide (CuSbS2) micro-and nanoparticles with a different shape and size have been prepared by a new approach to hot injection route. In this method, sulfur in oleylamine (OLA) is employed as a sulfonating agent providing a simple route to control the shape and size of the particles, which enables the optimization of CuSbS2 for a variety of applications. The sulfur to metallic precursor ratio appears to be one of the most effective parameters along with the temperature and time for controlling the size and morphology of the particles. The growth mechanism study shows in addition to the CuSbS2 phase the presence of not previously observed intermediate phases (stibnite (Sb2S3) and famatinite (Cu3SbS4)) at the initial stage of the reaction. By increasing the ratio of sulfur to copper and antimony, wider and thinner CuSbS2 particles are obtained. The particles have nanoplate and nanosheet morphology with a good shape and size uniformity. Coalescence of very thin nanosheets occurs with increasing reaction time eventually leading to formation of thicker particles which can be called nanobricks. Band gap determinations demonstrate that the obtained CuSbS2 particles have both direct (1.51-1.57 eV) and indirect (1.44-1.51 eV) bandgaps. Transmission Electron Microscopy (TEM) studies revealed that the preferred growth directions are along the basis axes of the unit cell ([100] and [010]). Optical and structural properties of the obtained CuSbS2 particles are indicative for their great potential in different generations of solar cells and supercapacitor applications.

We report an advanced method for the self-organization of an optomagnetic nanocomposite composed of both fluorescent clusters (ZnS quantum dots, QDs) and magnetic nanoparticles (CoFe2O4). ZnS nanocrystals were prepared via an aqueous method at different temperatures (25, 50, 75, and 100 °C). Their structural, optical and chemical properties were comprehensively characterized by X-ray diffraction (XRD), UV-Vis, photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), transmission electron microscopy (TEM), and infrared spectroscopy (FT-IR). The highest PL intensity was observed for the cubic ZnS nanoparticles synthesized at 75 °C which were then stabilized electrosterically using thioglycolic acid. The photophysical analysis of the capped QDs with particle size in the range 9-25 nm revealed that the emission intensity increases and the optical band gap rises compared to uncapped nanocrystals (3.88 to 4.02 eV). These band gaps are both wider than that of bulk ZnS resulting from the quantum confinement effect. Magnetic nanoparticles were synthesized via a coprecipitation route and a sol-gel process was used to form the functionalized, silica-coated CoFe2O4. Finally, thiol coordination was used for binding the QDs to the surface of the magnetic nanoparticles. The fluorescence intensity and magnetic properties of the nanocomposites are related to the ratio of ZnS and CoFe2O4. As-prepared optomagnetic nanocomposite with small size (12-45 nm), acceptable saturation magnetization (about 6.7 emu/g), and satisfactory luminescent characteristics could be successfully prepared. These are promising candidates for biological and photocatalytic applications.

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