Preparation&Catalysis Study Of Co₃O₄Nanoparticles And Its Core-Shell Structure Composites

Co3O4is a kind of transition metal oxdies of the Ⅷ subgroup element. As typical p-type semiconductor with empty electron orbitals, Co3O4possess excellent catalytic activity with a well ability to accept electron pair. Since morphology and particle size of nanoparticles have important effect on its catalytic performance, we prepared various kinds of Co3O4nanoparticles with different morphologies and particle sizes by controlling the experimental conditions. In addition, SiO2/Co3O4nanocomposite catalysts with different coating forms were prepared using SiO2as catalyst support.Co3O4nanoparticles with different morphologies and particle sizes were prepared through solvothermal method by controlling the experimental conditions, such as the types of cobalt salt, surfactant, precipitant, solvant, and the reaction temperature, to investigate the influence of different reaction conditions on morphologies and particle sizes of Co3O4nanoparticles. Different particle sizes of Co3O4on the catalytic effects of the thermal decomposition of ammonium perchlorate (AP) were studied by Differential scanning calorimetry (DSC).Highly dispersed SiO2microspheres with mean diameter of200nm were prepared by modified Stober method. Then the prepared SiO2nanoparticles were coated with Co3O4via liquid precipitation method and urea homogeneous precipitation method respectively, thus a new type SiO2/Co3O4core-shell catalysts with different coating forms were obtained. The thickness of Co3O4shell could be controlled by changing the concentration of precursor Co(NO3)2·6H2O.The catalytic activities of SiO2/Co3O4composites for thermal decomposition of AP were studied by DSC. The results indicate that the catalytic activity of SiO2/Co3O4nanocomposites on the thermal decomposition of AP is excellent, especially for particle-coated SiO2/Co3O4nanocomposites. And with the increase of Co(N03)2·6H20, the Co3O4shell thickness increase, which possess different catalytic activities.Co3O4/SiO2core-shell composites were synthesized by depositing SiO2on Co3O4nanoparticles by hydrolysis and condensation of TEOS precursor. The morphology and structure of Co3O4/SiO2composites were characterized by XRD, TEM, IR, Raman. The thermal decomposition effects of Co3O4and Co3O4/SiO2on AP were studied by DSC. The results show that Co3O4/SiO2nanocomposites possess vobvious core-shell structure, and excellent catalytic performance attributed to the protection of SiO2shell, which prevent the agglomeration of Co3O4nanoparticles.