Dielectric properties and microwaves response behavior of polypyrrole-derived N -doped carbon nanotubes

A series of N-doped carbon nanotubes (NCNTs) have been synthesized via a temperature-controlled annealing of polypyrrole (PPy) hierarchical nanostructures. The microstructures, dielectric properties and microwaves response behavior of these NCNTs were systematically investigated. The results indicate that initial pyrrolic N in PPy was gradually converted into pyridinic and graphitic N during the annealing process. NCNT prepared at 700 °C exhibits excellent broadband microwave absorption performance, where its effective absorption bandwidth (reflection loss value lower than − 10 dB) reaches 8.20 GHz in the frequency range of 9.80–18.00 GHz. A model refers to conductive loss and polarization relaxation was adopted to explain the high-performance microwave absorption. This research greatly expands the development of N-doped CNTs for the application in microwave areas.