Controlled Solution Synthesis And Characterization Of Manganese Compound Inorganic Materials

The goal of this dissertation is to enrich and develop the novel synthetic routes to prepare micron- and nano-scale inorganic materials based on solution synthesis. In this dissertation, a serious of inorganic materials of manganese compounds, such as binary manganese chalcogenides, manganese oxides, manganese oxysalts and ternary manganese chalcogenides, have been fabricated via various routes. The control of the morphology and size of the products has also been investigated. The detailed contents can be summarized as follows:1. A solvothermal technique using KBH4 as the reductant, element S (Se) as the S (Se) source has been developed to fabricate metastable y-MnS hollow spheres and a-MnSe uniform nanospheres and nanorods. The effects of the solvent, the reaction temperature, and the concentration and reducibility of the reductant on the phase of the MnS products are studied in detail. A possible growth mechanism for the γ-MnS hollow sphere is also tentatively proposed on the basis of the experimental results. Using the effects of the reaction temperature and the dispersion of the reactants in the solvent, the morphological control of the a-MnSe products can be successfully performed.2. An ultrasonic-assisted method has been developed to prepare colloidalnanoparticles with diameters about 5-10 nm at normal temperature and pressure through a similar seed-mediated growth process. The present method can be successfully extended to the synthesis of colloidal γ-Fe₂O₃ nanoparticles with diameter about 5 nm at room temperature in a closed system. All the products have a good crystallinity, and the particle size can be easily tuned by the reaction temperature without any additional size-selection process. A conventional thermal decomposition of precursor MnCO₃ has been used to synthesize α-Mn₂O₃ and MnO and the precursor MnCO₃ was synthesized by a hydrothermal reduction...