Novel porous FexCyNz/N-doped CNT nanocomposites with excellent bifunctions for catalyzing oxygen reduction reaction and absorbing electromagnetic wave

Abstract

In this work, a novel porous iron-based nanocomposite containing Fe3C, Fe3N, Fe (FexCyNz) and nitrogen doped carbon nanotubes (N-CNT) was designed and prepared. The typical product (FexCyNz/N-CNT-1000) possesses a unique characteristic of mesoporous structure with high BET surface area (401.5 m2 g−1) and outstanding electrocatalytic performance for oxygen reduction reaction (ORR) in alkaline solution, such as high limiting currents, superior methanol tolerance, relatively high stability and a near four-electron ORR pathway. More importantly, the onset potential of the representative sample is pretty close to that of commercial Pt/C. Surprisingly, the FexCyNz/N-CNT-1000 exhibits excellent electromagnetic (EM) wave absorption property, especially in the frequency range of C-band. The composite filled with 12% of FexCyNz/N-CNT-1000 sample in paraffin displays a maximum reflection loss (RL) of −25.1 dB at 4.5 GHz with a thickness of 4.0 mm, meanwhile, the absorption bandwidths below -10 dB (90% absorption) were 8.2 GHz with the variation thickness ranging from 2.0 to 5.0 mm. Consequently, we believe the present study provides a good reference for synthesizing novel multifunctional nanomaterials.