In-situ growth of NiCo bimetal anchored on porous straw-derived biochar composites for the boosted microwave absorption properties

As people's protection awareness about electromagnetic pollution is gradually increasing, the demand for absorbing materials with renewability and environmental friendliness has attracted widespread attention. In this paper, the straw-derived biochar combined with NiCo alloys composites were successfully fabricated in the process of high temperature carbonization and subsequent hydrothermal reaction. The electromagnetic parameters of porous biocarbon/NiCo composites can be effectively tuned by the NiCo contents. The porous biocarbon/NiCo composites present the improved absorbing performance due to the synergy effect of magnetic-dielectric characteristics. An exceptional reflection loss (RL) is -27.0 dB at 2.2 mm thickness and an effective absorption bandwidth can reach 4.42 GHz (11.71-16.13 GHz). These results demonstrate that the porous biocarbon/NiCo composite could be used as a new generation absorbing material because of low density, light weight, excellent conductivity, and strong absorption characteristics.