Constructing ohmic contact on hollow carbon nanocages to enhance conduction loss enabling high-efficient microwave absorption

Metal organic frameworks (MOFs) derived carbon materials have attracted much attention as hopeful electromagnetic microwave absorbents. However, the poor impedance matching and high filler content severely limited its electromagnetic absorption application. The introduction of hollow structural engineering is beneficial to improving microwave absorption performance. Herein, we designed and constructed Ni-incorporated hollow N -doped carbon nanocages (Ni/NCNs) to reveal interfacial charge transfer in electromagnetic wave attenuation. The hollow carbon structure facilitates impedance matching, highly dispersive Ni nanoparticles not only build a dense magnetic coupling network but also generate a series of Ohmic contact heterogeneous interfaces with hollow NCNs, extremely accelerating the charge transfer and enhancing conduction loss. Thanks to hollow structure, optimized impedance matching, and abundant Ohmic contact heterogeneous interfaces, the Ni-50/NCNs exhibit a minimum reflection loss of -57.3 dB. The results demonstrate that Ni-50/NCNs composites have great potential to be considered efficient electromagnetic wave materials, and the designed Ohmic contact heterogeneous interfaces pave the way in the study of electromagnetic wave absorption mechanisms.