Enhanced microwave absorption of g-C3N4/poly(vinylidene difluoride)/carbon black composites

Abstract

The two-dimensional (2D) nanostructures have been widely applied as microwave absorption materials due to their unique structural features towards electromagnetic wave absorption. Herein, we have prepared graphitic carbon nitride (g-C3N4) nanosheets with a facile synthesis process, and then it was composited with a minimal amount of polyvinylidene difluoride (PVDF) and carbon black (CB) to enhance the microwave attenuation of g-C3N4 and to present an eco-friendly and cost-effective microwave absorbing material (MAM) as g-C3N4/PVDF/CB. The designed g-C3N4/PVDF/CB composite delivers a maximum return loss of −30.93 dB at 11.44 GHz, corresponding to an absorption efficiency of over 99.92%, with an average return loss of −17.29 dB. However, the dielectric performances were also elucidated with independent contributions of dielectric constant, tangent loss, and conductivity towards the microwave absorption performances. The integration of absorption medium PVDF and conductive medium CB to g-C3N4 offers the excellent absorption ability of g-C3N4/PVDF/CB. Hence, in the exploration of new MAM, g-C3N4/PVDF/CB may be an attractive microwave-absorbing material with strong dielectric parameters and excellent absorption effects.