Shape-controlled synthesis of cobalt particles by a surfactant-free solvothermal method and their catalytic application to the thermal decomposition of ammonium perchlorate
Abstract
Submicro-Co particles with different morphologies were successfully synthesized by a simple solvothermal and surfactant-free approach. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images revealed that the average size was approximately 2 μm and the microstructure of the as-synthesized particles could be regulated by the contents and ratio of Co2+/NaOH. The phase structure and composition of the as-synthesized samples were characterized by X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS) and Raman spectroscopy. The results indicated that the as-synthesized Co particles were covered with a thin layer of CoO. Based on time-dependent experiments, the growth mechanisms of three kinds of typical structures and morphologies were proposed. The magnetic hysteresis loops showed ferromagnetic characteristics and the best saturation magnetization (Ms) and coercivity (Hc) were found to be 162.5 emu g−1 and 104.3 Oe, respectively. Moreover, the exothermic peak of ammonium perchlorate thermal decomposition shifted towards the lower temperatures by 108 °C through addition of 4% Co particles, indicating that the Co particles exhibited a good catalytic effect for potential applications.