Controllable fiberization engineering of cobalt anchored mesoporous hollow carbon spheres for positive feedback to electromagnetic wave absorption

In order to overcome the limitations of single attenuation mechanism materials in effectively absorbing electromagnetic waves (EMW), meticulous microstructural design of composites and an elevated degree of integration of wave absorbing mechanisms are crucial. Utilizing mesoporous hollow carbon spheres as precursors, PCHM@Co_mX_n (X = Se, S, O) nano-microspheres were synthesized by anchoring cobalt nanoparticles on the surface, controllable encapsulating in continuous fiber structure by electrostatic spinning technique subsequently. The carbon shell-cavity core configuration interspersed with nanoparticles has the advantage of light weight, low density and extensive defects. Abundant heterogeneous interface in carbon fiber offers excellent electrical conductivity and high specific surface area, while a three-dimension conductive network optimizes the transmission loss to incident EMW. The efficient synergy of multiple mechanisms enables PCHM@CoSe₂/CNFs to achieve a strong reflection loss of −50.55 dB at a matched thickness of 2.0 mm, while the EAB_max value can be extended to a remarkable 6.80 GHz at 2.3 mm, which is considerably superior to fiber samples encapsulating other cobalt-based nanoparticles of the same family. This work provides an innovative direction for the development of high-performance EMW absorbers.