Restricted growth of molybdenum carbide nanoparticles in hierarchically porous nitrogen-doped carbon matrix for boosting electromagnetic wave absorption performance.

With the development of electronic science and technology, electromagnetic pollution is becoming increasingly serious, which urgent people to develop wave-absorbing materials with the features of "thin, light, strong and wide". In this paper, restricted growth of molybdenum carbide nanoparticles in hierarchically porous nitrogen-doped carbon matrix (MoC/NC) was designed and prepared via a salt-assisted template route and carbonization process, whose morphology and the wave-absorbing properties are regulated by changing the content of MoC/NC nanoparticles. The honeycomb porous MoC/NC composites with large specific surface area and smooth surface can optimize the impedance matching and allow the entrance, multiple reflections and scattering of incident electromagnetic waves (EMW), which effective enhance the electromagnetic wave consumption. Meanwhile, the honeycomb cross-linked carbon matrix facilitates the construction of the conductive network and enhances its conductive loss. Furthermore, numerous MoC/NC nanoparticles dispersed restricted growth in carbon matrix induces interfacial polarization. In addition, the heteroatom nitrogen doping acts as dipole centers to induce dipole polarization under electromagnetic field. The uniquely designed MoC/NC absorbers show satisfactory EMW absorption behaviors of a minimum reflection loss (RL) of -61.53 dB at 1.5 mm and an effective absorption bandwidth (EAB) of 9.6 GHz at 3.5 mm. This work enriches the variety of EMW absorbers and offers the route to promote the EMW absorption performance, especially large effective absorption bandwidth.