Three-dimensional melamine sponge hollow carbon/Ni3ZnC0.7/carbon nanotubes with tunable high-performance microwave absorption performance

Constructing three-dimensional microstructure with special morphology is an important method to improve the flexibility, low density and high performance of absorbing materials. Herein, Ni3ZnC0.7/carbon nanotubes/ melamine sponge hollow carbon (NZC/CNTs/SHC) composites were prepared by vacuum filtrating precursor containing NiZn ions and CNTs followed with calcining under N2 flow. The loading of NZC/CNTs can be tuned by controlling the filtrating time of 0.5, 1 and 2 h. The Ni3ZnC0.7 and CNTs were uniformly dispersed on the surface of melamine sponge carbon skeleton and the carbon shows hollow structure. The 2-NZC/CNTs/SHC composite (filtrating time of 2 h) exhibited a minimum reflection loss (RL) value of -114.5 dB (1.3 mm) and an effective absorption bandwidth (EAB, RL<-10 dB) of 12.5 GHz at a matching thickness of 1.9 mm. The outstanding wave -absorbing properties of NZC/CNTs/SHC composites can be attributed to their unique hollow structure, which results in multiple reflections and scattering, interface/dipole polarization, improved dielectric and magnetic attenuation capability.

Automated summary

Constructing NZC/CNTs/SHC composites with hollow structure by vacuum filtration and calcination can provide excellent wave-absorbing properties due to multiple reflections and scattering, interface/dipole polarization, and improved dielectric and magnetic attenuation capability.