Large-scale preparation of Co nanoparticles as an additive in carbon fiber for microwave absorption enhancement in C band
Yingying Zhu, S. F. Wang, Y. S. Zhang, Zhigang Wu, Bo Zhong, D. R. Li, Fengcai Wang, J. J. Feng, Jun Tang, Ran Zhuo, Pengzhi Yan
Abstract
Recent studies have found that the core-shell structured metal nanoparticles and porous carbon nanofibers (PCNF) are combined into a microwave absorbing material through electrospinning, which exhibits excellent microwave absorption performance. In this study, the core-shell structure Co nanoparticles prepared by the self-developed HEIBE process (production rate of > 50 g/h) were combined with porous carbon fibers, and their absorbing properties were greatly improved. The morphology of Co/PCNF demonstrated that CoNPs are randomly dispersed in the porous carbon nanofibers and carbon nanofiber form complex conductive network which enhances the dielectric loss of the materials. Meanwhile, the Co/PCNF has a low graphitization and shows a significant improvement in permittivity due to the combination of CoNPs and high conductivity of carbon material. The maximum reflection loss (RL) of Co/PCNF reaches - 63.69 dB at 5.28 GHz with a thickness of 5.21 mm and the absorption bandwidth (RL ≤ - 10.0 dB) is 12.92 GHz. In terms of 5.60 mm and 6.61 mm absorber, there are two absorption peaks of - 47.64 dB and - 48.30 dB appear around 12.50 GHz and 14.10 GHz, respectively. The results presented in this paper may pave a way for promising applications of lightweight and high-efficiency microwave absorbing materials (MAMs).