Construction of MnO-skeleton cross-linked by carbon nanotubes networks for efficient microwave absorption

Constructing nanostructures with abundant heterogeneous interfaces is highly efficient in improving microwave absorbing properties. Herein, a simple chemical vapor deposition (CVD) route for the in-situ growth of carbon nanotubes (CNTs) in the voids of MnO particles clusters skeleton has been developed to fabricate MnO/CNTs heterostructure composites with tunable dielectric properties. The optimized MnO/CNTs-1 composite with 45 wt% CNTs content exhibits comprehensive enhanced microwave absorption performance, with the minimum reflection loss (RL_min) can reach -50.6 dB (20 wt% in paraffin composite). The effective absorption bandwidth (RL < -10 dB, 90% absorption) up to 13.7 GHz was achieved by adjusting the thickness from 2 to 5 mm, covering the entire C, X and Ku bands. Herein, the MnO particles and CNTs networks act as skeleton and crosslinker, respectively. The MnO particles attached throughout the CNTs networks can provide multiple interfacial polarization and multiple scattering/reflection. Our works provide new insights for the facile designing lightweight nanostructure to enhance the microwave absorption performance of the CNTs.