Synthesis And Characterization Of Antimony-based Namomaterials Via A Hydrothermal Method

The morphologies of materials are often regarded as particularly important factors that influence the chemical or physical properties of products. Shape-controlled synthesis of well-defined inorganic nanocrystals have received considerable attention. As a result, much effort has been explored for rational controlling over shape, size, dimensionality, and complexity of nanocrystals. Various methodologies have been developed to synthesize the well-defined morphologies. In this paper, two methods have been carried out to controll the morphologies:on the one hand, the morphologies of materials are restricted via the choice of appropriate addctives such as surfactants and the tatio of mixture solvents; on the other hand, the morphologies of materials are restricted via the optimization of the experiments conditions and parameters. Herein, we report the fabrication of the Sb2O3 products with three different uniform microarchitectures via a facile hydrothermal synthetic method and the structures, properties and possible mechanisms leading to the microarchitectures were proposed, respectively.The main works and results are followed as bellow:(1) The bow-tie-like antimony trioxide (Sb2O3) nanostructures composed of nanosheets which have a width of-400 nm, a length of up to-2μm, and a thickness of-50 nm, have been successfully synthesized in a large scale via a facile hydrothermal method from the mixture of aqueous solutions of SbCl3 and Na2CO3 at 120℃for 12h without using any surfactant or template. Results from XRD, SEM TEM, BET, UV-vis and PL measurements were carried out to characterize the resulting precipitates. The results show that the products can be indexed as orthorhombic phase Sb2O3 and consist of particles with nearly uniform and monodispersed bow-tie-like nanostructures, also, the products exhist excellent optical property. The bow-tie-like Sb2O3 nanostructures exhibit superior optical properties. On the basis of these results, possible growth mechanism for the formation of bow-tie-like Sb2O3 nanostructures is presented and discussed.(2) Sb2O3 nanostructures with different morphologies, such as spindle-like hollow microstructure and cobblestone-like particles, have been successfully synthesized with cetyltrimethylammonium bromide (CTAB) as a soft-template via a hydrothermal method. When the kind of mixture solvents is controlled, Sb2O3 products with different morphologies can be selectively produced. It was found that the experimental parameters, such as the reaction temperature, time and mineralizer, played crucial roles in the respective morphological control of Sb2O3 structures. On the basis of these results, possible growth mechanisms for the formation of hollow spindle-like and cobblestone-like microstructures are presented and discussed. It is found that the shapes of micelle forned by CTAB in different solvents played a key role in determining the product morphology. What't more, Results from Raman and BET measurements were carried out to characterize the resulting pruducts. The Raman spectroscopic study indicated that the obtained Sb2O3 samples were high pure and good crystallizability of orthorhombic-phase Sb2O3 crystal. Comparing with the cobblestone-like Sb2O3 particles Raman spectrum, the hollow spindle-like Sb2O3 microstructures Raman spectrum not only was the intensity of the vibrational modes greatly decreased, but also were the frequencies of Raman bands down shifted. The materials have a large surface area of 9.61 m2 g-1 and a uniform mesoporous diameter of 18.64 nn.(3) Sb2O3 nanowires with great aspect ratio, about 233 nm in diameter, and microspheres assembled by nanowires were successfully synthesized using a simple hydrothermal method involving polyvinyl alcohol (PVA) as a self-assembly reagent.The morphologies and structural properties of the as-grown Sb2O3 nanowires and microspheres were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FIRT) and thermogravimetry analysis (TGA). It was found that the experimental parameters, such as mineralizer, played crucial roles in the morphological control of Sb2O3 nanowires. The possible growth mechanism has been discussed. PVA played a crucial role in the self-assemble formation of Sb2O3 microspheres. The photocatalytic activities towards degradation of rhodamine B (RhB) by Sb2O3 nanowires and microspheres under UV light has been investigated. It is found that the products modified by dopants, such as TiO2, ZnO and Co2O3, exhibited remarkable photoactivity.