Hierarchical Three-Dimensional Cobalt Phosphate Microarchitectures: Large-Scale Solvothermal Synthesis, Characterization, and Magnetic and Microwave Absorption Properties
文摘
Novel hierarchical cobalt phosphate (α- and β-Co2P2O7) and cobalt hydrogen phosphate hydroxide [Co11(HPO3)8(OH)6] three-dimensional (3D) architectures with different morphologies were synthesized under a solvothemal condition. The form and shape of cobalt phosphate can be readily tuned by adjusting experimental parameters of the reaction system. The novel hierarchical α-Co2P2O7 microcrystals with basketry-like microstructures were obtained with a molar ratio of Co2+/H3PO4/CH3NH2/HO(CH2)2OH of 1:1.2:1:108, the reaction temperature of 180 °C, and the reaction time of 5 days; dumbbell-like β-Co2P2O7 microspheres were formed with the same reaction temperature and time but the molar ratio of 1:1.2:1:54, and Co11(HPO3)8(OH)6 with peony-like nanostructures was prepared with the same molar ratio and reaction time as β-Co2P2O7 but the reaction temperature of 120 °C. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectra (FT-IR) technologies, a Quantum Design superconducting quantum interference device (SQUID) magnetometer, and a network analyzer. The formation mechanism of cobalt phosphate microstructures was investigated in detail.