N-doped carbon hollow spheres supported N-doped carbon nanotubes for efficient electromagnetic wave absorption

Abstract

Hierarchical and hollow heteronanostructures had attached wide attention in electromagnetic wave (EMW) absorption fields due to their adjustable impedance matching and loss property. However, fabrication of well-defined heteronanomaterials with hierarchical and hollow features is challenging. Here, we develop a simple method to prepare N-doped carbon hollow spheres supported by N-doped carbon nanotubes (Ni@NCNT/NCHSs). Due to the hierarchical and hollow features, the Ni@NCNT/NCHSs exhibit high-efficiency EMW absorption performance. With a thickness only 1.6 mm, the optimized heteronanostructure has an RLmin of −64.75 dB and an EAB of 4.17 GHz. The experimental results demonstrate that the hierarchical and hollow heteronanostructures have significantly enhanced dielectric loss and conductive loss of the Ni@NCNT/NCHSs as well as the impedance matching characteristics, which are responsible for their enhanced EMW absorption performances. This work presents an effective method to synthesize hierarchical and hollow heteronanostructures for high-performance EMW absorption.