▎ 摘　　要

SiC/graphene nanocomposites were rapidly synthesized by hexamethyldisilane and methane decomposition in atmospheric plasmas. Results indicate that the products without methane addition were SiC/C composites composed of SiC nanoparticles with dimension of 5-30 nm and carbon nanoshells with few layers. With the addition of methane, graphene nanosheets with 1-8 layers generated, and they attached with SiC nanoparticles and carbon nanoshells, forming SiC/graphene nanocomposites with point-surface structure. The formation of graphene nanosheets improved the microwave absorption ability, and the optimal reflection loss approached -65.7 dB at 11 GHz with an absorber thickness of 1.6 mm. Electromagnetic parameters indicated the improving microwave absorption was associated to the enhanced polarization/conduction loss due to the formation of point-surface structure.