3D Composites of CNTs Vertically Grown on Xuan Paper Fibers and Their Microwave Absorption Application

Carbon nanotubes (CNTs) have attracted considerable attention as promising microwave-absorbing materials because of their excellent electrical conductivity and superior mechanical properties. In this study, vertical CNTs were conformally grown on Xuan-paper fibers via chemical vapor deposition (CVD). The inherent penetration and capillary-diffusion characteristics of Xuan paper enable rapid transport of the catalyst solution and uniform distribution of catalytic nanoparticles throughout the fiber network. Hydroxyl groups on the cellulose fibers anchor these nanoparticles through hydrogen bonding and polar interactions, ensuring stable immobilization of catalyst. The structure of vertical CNTs growing on the fibers exhibits outstanding microwave-absorption performance with the RL min of −23.2 dB at 5.12 GHz in the case of 6.5 mm and the effective absorption bandwidth of 5.1 GHz (4.1–6.16 GHz and 14.64–17.68 GHz). This strategy offers a novel route for fabricating three-dimensional CNT-based composites and bridges traditional craftsmanship with modern nanotechnology.