Synthesis Of Morphology Controllable Cobalt Oxide And Research Catalytic Properties

With the deveopment of science and technology, the synthesis of novel morphologiesand superior performance of Co₃O₄has become the focus of researchers due to the extensiveapplications in electrochemical, magnetic, sensor, catalyst, and so on. In this paper, Co₃O₄particles with different morphologies have been prepared through hydrothermal-thermaldecomposition method and solvothermal-thermal decomposition method. The correspondingreaction mechanisms of several products were discussed. Furthermore, the thermaldecomposition properties of ammonium perchlorate（AP） of different morphology of theproducts were studied. The main contents are as follows:Co₃O₄microspheres with rough surface were successfully synthesized with theassistance of sodium dodecylsulphonate（SDS）. The effects of experimental conditions onmorphology and phase have been investigated, such as solvent system, alkali source andcobalt source. The formation mechanism of the Co₃O₄micspheres was explored briefly bycomparing the morphology of the samples obtained with or without the assistance of SDS,and SDS played the role of surfactant and template agent. The decomposition rate of theprecursor gradually increased and the decomposition of CO₂gas escaped fiercely from themicrospheres with the increase of calcination temperature, which results in the breakage andshrinking of the microspheres, so Co₃O₄with different morphologies were prepared.Peanu-like Co₃O₄stacked small nanoparticals was synthesized by solvothermal-thermaldecomposition method. The characterizations such as XRD, SEM and TEM、FTIR andTG-DSC were used to detect and analyze the composition, structure and morphology of theproducts. After exploring the influence of solvent, hydrothermal reaction temperature andtime on the morphology and phase of the precursor, it was concluded that the most suitablecondition for preparing CoCO3with the most complete peanut-like morphology was thatsolvent was ethylene glycol, reaction temperature was180oC and time was24hours, and thenpeanut-like Co₃O₄was prepared by calining the precursor.The nano-level and micron-level Co₃O₄particles could be obtained by calcining thesame precursor at different temperatures. the precursor nanoparticles were synthesized usingethylene glycol, Hexamethylenetetramine, SDS as the starting materials. When the calcination temperature were500oC and700oC, the products are20～40nm and100～300nmnanoparticles, respectively. When the calcination temperature was900oC,1～2μm micronparticles can be prepared. Due to the existence of sintering phenomenon, the paticle size ofthe products increases with the increase of calcintion temperature.The thermal decomposition of ammonium perchlorate of the different morphologiesCo₃O₄particles were studied by using TG-DSC analytical method. The results showed thatCo₃O₄particles with different morphologies have to some extent impact on the thermaldecomposition of ammonium perchlorate, especially, Co₃O₄microsphere that was prepared bycalcinating at350oC. The decomposition temperature range of ammonium perchlorate wasdecreased from284～452oC to223～316oC by the catalysis of Co₃O₄microsphere.