Tailoring conductive network nanostructures of ZIF-derived cobalt-decorated N-doped graphene/carbon nanotubes for microwave absorption applications

摘要

Confronted with microwave pollution issues, there is an urgent need for microwave absorption materials that possess optimal combinations of dielectric loss and magnetic loss properties. While a variety of studies focus on the components, the construction of nanostructure is rarely studied, which is of equivalent significance to microwave absorber design. In this work, Co-ZIF-67 was adopted as self-template to grow N-doped graphene/carbon nanotube interlinked conductive networks in-situ under a one-step carbonization process with tailored microwave absorption properties. Diverse microwave absorption performance could be achieved by directly adjusting the proportions among ingredients and the calcination temperature, obtaining a maximum value of reflection loss of-65.45 dB at 17.5 GHz with a sample thickness of just 1.5 mm. The effective absorption bandwidth could be tailored from 3.75 to 18 GHz among different thickness as required. The nanostructures had an apparent impact on the corresponding microwave absorption performance, in which the N-doped carbon-based conductive networks, ferromagnetic cobalt atoms, and interfaces among heterostructure strengthened the dipolar polarization and conductivity loss, magnetic loss, and interfacial polarization, respectively. This synthesis strategy offers a promising pathway for integrating nanostructures and functions, catering to requirements for designing and optimizing prospective microwave absorbers. (c) 2021 Elsevier Inc. All rights reserved.