Electrospinning and in-situ hierarchical thermal treatment to tailor C–NiCo2O4 nanofibers for tunable microwave absorption

The development of high-efficiency microwave absorbing materials in different frequency bands is expected to satisfy the requirement of real-time communication and national defense especially active camouflage in the information era. Herein, a carbon modified nickel cobalt oxide, C–NiCo2O4, porous nanofiber is successfully constructed by electrospinning and in-situ hierarchical thermal treatment engineering. The thermal treatment temperature enables tailoring of the C content of C–NiCo2O4 so as to modulate the conduction loss. More importantly, the absorption frequency can be tuned from Ku to X and even to C band due to that the proper tailoring affords varying synergy effect of dielectric and magnetic properties on impedance matching degree of each C–NiCo2O4 composite. Since low reflection loss suggests efficient energy conversion and heat generation, the high electromagnetic absorption makes the material extremely potential for application in multifunctional nano-micro electromagnetic devices.