Huijing Yang

NiO Hierarchical Nanorings on SiC: Enhancing Relaxation to Tune Microwave Absorption at Elevated Temperature

We fabricated NiO nanorings on SiC, a novel hierarchical architecture, by a facile two-step method. The dielectric properties depend on temperature and frequency in the range from 373 to 773 K and X band. The imaginary part and loss tangent increase more than four times and three times with increasing temperature, respectively. The architecture demonstrates multirelaxation and possesses high-efficient absorption. The reflection loss exceeds -40 dB and the bandwidth covers 85% of X band (approximately -20 dB). The synergistic effect between multirelaxation and conductance is beneficial to the microwave absorption. Our findings provide a novel and feasible strategy to tune microwave absorption.

Graphene nanohybrids: excellent electromagnetic properties for the absorbing and shielding of electromagnetic waves

Graphene has been long sought-after over the past few decades because of its multiple functions and broad applications in various fields, such as energy, information, medicine, military equipments, and aerospace. In particular, it has been significantly reported in electromagnetic wave absorbing and shielding fields, promoting it as the most cutting-edge topic. Herein, we systematically comb the structures and electromagnetic functions of graphene hybrids. We demonstrate the advances in the microwave response mechanism, including relaxation, charge transport, magnetic resonance, and eddy currents, as well as magnetic-dielectric synergistic effects. Furthermore, our review mainly focuses on graphene-dispersed systems, flexible graphene papers, graphene hybrids, and 3D graphene architectures.