Structure control and growth mechanism of beaded SiC nanowires with microwave absorption properties

Large-scale SiC nanowires (SiCnws) were successfully synthesized on graphite substrates by a catalyst-free carbon thermal reduction process using low-cost silicone oil, silica powder, and activated carbon. The control of different nanowire structures was achieved by parameter regulation. An in-depth discussion of their growth mechanisms is provided. Beaded SiCnws consisting of amorphous SiO2 beads and SiC strings were synthesized at 1400 °C. The formation of beads is mainly due to the supersaturation of SiO vapor, which leads to the reaction of excess SiO to form SiO2 at the defects of the SiCnws. The dielectric parameters of beaded SiCnws were analyzed, and it was found that the beaded SiCnws have a maximum effective absorption width of 1.84 GHz and a maximum reflection loss of −16.03 dB. The exploration of the growth mechanism of beaded SiCnws in this study provides a useful reference for the preparation of one-dimensional nanomaterials.