0D/1D/2D architectural Co@C/MXene composite for boosting microwave attenuation performance in 2–18 GHz

Ti₃C₂T_x is considered a candidate for high-efficiency microwave absorption materials due to its adjustable electrical conductivity, low density and high specific surface area in recent years. However, the single absorption mechanism could not meet the practical requirements as the functional microwave absorbers. Herein, 0D/1D/2D architectures of Co@C/MXene with 0D Co nanoparticles, 1D carbon nanotubes (CNTs) and 2D Ti₃C₂T_x MXene nanosheets were rationally fabricated to enhance the microwave attenuation performance, in which Co@CNTs were in situ grown on Ti₃C₂T_x MXene nanosheets. By changing the amount of Ti₃C₂T_x MXene to optimize the impedance matching properties, the Co@C/M − 10 absorber exhibits excellent microwave attenuation performance with a minimum reflection loss of −50.5 dB at 5.9 GHz under a thickness of 4.0 mm. Meanwhile, the maximum effective absorption bandwidth (<−10 dB) of Co@C/M − 10 absorber can reach 5.8 GHz under 2.0 mm. The remarkable absorption performance can be ascribed to the synergistic effects of interface polarizations and magnetic loss. Moreover, the radar cross section (RCS) simulation was also performed via CST. Under the incident angle of 0°, the RCS reduction value of Co@C/M − 10 can reach 33.5 dBm². This work provides a strategy for synthesizing MXene-based composite materials with tunable electromagnetic attenuation and wide absorption bandwidth performance.