Nano Bimetallic@Carbon Layer on Porous Carbon Nanofibers with Multiple Interfaces for Microwave Absorption Applications

Porous carbon fibers (FeCo@C-PCFs) hybrids are fabricated by a two-step process involving the electrospinning followed by heat treatment, in which several steps are involved including the reduction of polyvalent metal ions, the produced alloy nanoparticles are encapsulated into porous carbon substrate, yielding the FeCo-polyacrylonitrile networks (FeCo-PAN) that are formed in situ and function as the building blocks. After altering feeding proportion of Co2+ and Fe3+, the formation of FeCo@C-PCF compounds could be controlled. More importantly, FeCo alloys seem to have higher chemical stability. With different graphitization degrees, FeCo@C-PCF compounds were proven to be outstanding microwave (MW) absorbent including thickness, effective bandwidth, and reflection loss (RL). The maximum RL values reached −56 dB at 1.85 mm and broadest bandwidth was 8.3 GHz.