Abstract
Carbon materials have gained significant attention for their potential as highly efficient microwave absorbers. However, it remains a challenge to attain a perfect integration of thin thickness, wide frequency bandwidth, lightweight and strong absorption through structural design of carbon materials. Herein, we design multidimensional and hierarchical carbon nanofiber networks consisting of core -shell carbon nanofibers wrapped by hollow carbon nanoparticles, named CPDA@RCNFs. CPDA@RCNFs which are derived from cellulose and polydopamine (PDA) were prepared by electrostatic spinning, deacetylation, self -polymerization, and carbonization, successively. Thanks to the cooperation of three-dimensional conductive networks, core-shell/hollow/ porous structures, as well as doped nitrogen and oxygen heteroatoms, CPDA@RCNFs exhibit excellent comprehensive microwave absorption performance. Specifically, an ultra -strong reflection loss value of -63.31 dB and a wide frequency bandwidth of 5.60 GHz (12.32 -17.92 GHz) are achieved at a very thin thickness of 1.8 mm with an ultra -low filler loading of 5 wt%. This work provides a new insight into the structural design of advanced high-performance microwave absorption carbon materials.