Carbon Nanotube Grown from Cobalt Supported on Biomass-Derived Carbon as Nanocomposite for the Attenuation of Electromagnetic Waves

In applications such as aerospace, automotive, and mobile devices, reduction of weight is crucial for enhancing the performance, minimizing the energy expenditure, and extending the operational lifespan. Lightweight electromagnetic wave-absorbing materials offer a viable solution to achieve these objectives without compromising the absorption efficiency. Additionally, the cost-effective production of these materials facilitates large-scale manufacturing, thereby broadening the application scope of electromagnetic wave absorption technology. In this study, an ultralight hierarchical biomass-derived porous carbon (BPC)/Co/carbon nanotube (CNT) composite was prepared highly efficiently by employing a microwave plasma-assisted reduced chemical vapor deposition technique. Taking advantage of the renewable wood, the BPC served as the matrix, in which CNTs with magnetic Co nanoparticles were grown on the surface of the BPC. The hierarchical structure with zero-dimensional Co nanocrystals, one-dimensional CNTs, and three-dimensional BPC matrix could fertilize the loss mechanism availably, which was rationally endowed with enhanced electromagnetic wave dissipation capacity under a low loading content. Consequently, the composite demonstrated a remarkable minimum reflection loss of −78.7 dB at a thin matching thickness of 1.9 mm despite having a filler content as minimal as 10 wt %. Furthermore, the radar cross-section could be significantly reduced to 21.5 dB m 2 when the detection angle was fixed at 20°. This work offers insights into designing and fabricating next-generation ultralight electromagnetic wave absorbers through a cost-effective, ecofriendly, and efficient approach.