Synthesis, characterization and microwave dielectric properties of flower - like Co(OH)2/C nanocomposites

Abstract

Flower-like Co(OH) 2 /C nanocomposites have been synthesized by a facile hydrothermal method. Flower-like Co(OH) 2 /C nanocomposites were self-assembled by the nanosheets with the thickness distribution of 50-80 nm and abundant flocculent carbon structures. With the help of transmission electron microscopy and energy dispersive spectrometer, nanosheets were observed to have core/ shell structure, in which Co(OH) 2 worked as cores and amorphous C as shells. When the as-prepared products were heated for 6 h at 180 °C, the Co(OH) 2 cores were amorphous. The heating time increased to 10 h, the Co(OH) 2 cores became crystalline. The formation mechanism and the self-assembly evolution process were proposed. The microwave dielectric properties of Co(OH) 2 /C nanocomposites were investigated in the frequency range of 0.03-18 GHz. Compared with the amorphous Co(OH) 2 /C nanocomposites, crystalline nanocomposites had the better conductivity.