Synthesis, Characterization And Properties Of Manganese And Iron Oxides Nano-microspheres

Nano structural materials exhibit a lot of excellent performance, such as small density, high BET specific surface areas and nano sphere paries. It is always shown different physicochemical properties and has potential application in many fields. The synthesis and performance of nanometer materials is an exciting research field. The the synthesis of transition metal oxides that and their properties obtained particular attention. In this study, nanostructure Micro-Spheres transition metal oxide is fabricated by hydrothermal method. The samples were characterized by using XRD, SEM, TEM, DTA /TG, and so on. The catalysis and electrochemical performance of the sample were investigated. The results were summarized as follows:1.Urchin Nanometer sphere were fabricated via hydrothermal method using reagent-grade ammonium persulfate and manganese sulfate as the staring materials. The reactions were carried out by control reaction temperature and time without surfactant and catalyst. And the structures of urchin nanometer sphere were studied. The results show that: spheres are composed of nano-fiber or nano-rods, diameter of sphere is about 5μm, length of nano-rods is about 2³Î¼m. The diameter of nano-rods become coarsen and shorter with increase of temperature or time, the structural transformation from nano-fiber(5nm) to nano-rods(60nm).2.This paper investigated the MnO₂ catalytic performance by catalyze thermal decomposition of potassium chlorate and retrogradation methylene blue with catalyze H₂O₂. The results show that: MnO₂ urchin Nanometer sphere with uniform and complete sphere structure which was synthesized at Hydrothermal temperature 100℃, 40h (100℃*40h) effect was obviously to thermal decomposition of potassium chlorate, Thermally decomposed temperature decreased 230℃, Thermally decomposed step decreased for one. Decomposition rate of retrogradation methylene blue with catalyze H₂O₂ is more than 60% by add 0.2g Nanometer sphere(Hydrothermal temperature 120℃*36h).3.In this work, MnO₂ electrochemical performance was studied by test performance of CV and constant current charging-discharging. The results show that: The CV and constant current charging-discharging of Core-Shell and hollow shell structured urchin nanometer sphere constitute ofβ-MnO₂ andγ-MnO₂ better than other hydrothermal products, and the specific capacitance was as high as 210 F·g^-1. MnO₂ performs good electrochemistry property, and it can apply to composite electrode material for super capacitor. 4.Urchin, framboid or dumb-bellα-Fe₂O₃ nanometer sphere were synthesized by hydrothermal method using demonized water and iron sulfate as raw materials. The reactions were carried out by control reaction temperature or time without surfactant and catalyst, and the structure of urchin nanometer sphere were studied. The results show that: nanometer sphere are composed of nano particles, the size of nano particle is about 50⁶0nm.5.The catalytic performance ofα-Fe₂O₃ was investigated by catalysis thermal decomposition of solid propellant of ammonium perchlorate. The results show that: The accession flower and urchin microspheres, which were synthesized at hydrothermal condition 140℃*8h, exhibit significantly effect on catalysis thermal decomposition of ammonium perchlorate. Thermally decomposed temperature decreased 70℃, catalytic effect is significant.