Heterointerface engineering in Cr2GaC/C hybrids through bottom-up template synthesis for enhanced electromagnetic wave absorption

Abstract

MAX phases are emerging as efficient electromagnetic wave absorption (EMA) materials, favored for their outstanding conductivity, high-temperature stability, and corrosion resistance. However, the limitations of a singular energy loss mechanism and the need for a high filler ratio hinder their further development. Herein, a template method utilizing absorbent cotton as a carbon source was employed to synthesize 0D/1D Cr2GaC/C hybrid materials. The bottom-up preparation strategy maintains the size of the Cr2GaC MAX-phase particles at ~200 nm while ensuring their uniform distribution within the carbon fibers. The abundant heterointerfaces between Cr2GaC and carbon enhanced interfacial polarization, while the carbon fiber network improved conduction loss. Consequently, the Cr2GaC/C hybrid exhibits excellent EMA properties, achieving a minimum reflection loss value of -59.0 dB at a thickness of only 1.56 mm and an ultra-low filler content of 15 wt.%. Additionally, its maximum radar cross section reduction value is 17.78 dB m², showing excellent stealth capability. This research provides new insights into the nanoscale synthesis of MAX phases and offers promising pathways for optimizing their EMA performance.