“Appropriate dressing” non-fluorination strategy: Dopamine coating CuSiF6 framework derived F-rich SiC/CuF2@C electromagnetic wave absorber

Abstract

For enhancing the electromagnetic wave (EMW) absorbing performance of SiC-based composites, constructing multiple interface polarization and defects through doping highly electronegative fluoride (F) is of great significance. However, integrating F constituent into SiC composites using presently available fabrication techniques of fluorination with high-temperature sintering really remains a challenge due to the pronounced temperature sensitivity and the chemical activity of fluoride. Herein, we present a facile one-step “non-chemical fluorination” strategy on a PDA-coated CuSiF6 framework with optimal “chemical dressing”, which generated a high-performance EMW absorber (denoted as SiC/CuF2@C-5) with intense reflection loss (RLmin) of −42.74 dB and broad effective absorption bandwidth (EAB) of 5.6 GHz (9.12–14.72 GHz). The proper PDA-coated on CuSiF6in situ induced the uniform distribution of SiC and doping of electronegative F-sites in the carbon matrix, eliminating the extra fluorination procedure and preventing the gasification of fluoride. Moreover, generated abundant hetero-interfaces, and the enriched defects regulated polarization loss and impedance matching. This work presents a promising synthesis strategy for high-performance SiC-based EMW absorbing material.