Regulating long-range travelling electrons for simultaneous electromagnetic absorption and interference shielding of Co@C nanofibers

Multifunctional electromagnetic nanofibers are potential in wearable wireless devices. Manipulating the electromagnetic response of a material is a reasonable strategy for developing diversified electromagnetic functions. Herein, a multifunctional electromagnetic nanofiber (Co@C) is proposed. Due to the intrinsic local π-bonds, residual defects/groups, heterogeneous interfaces, and magnetic multiresonance, Co@C nanofibers show excellent electromagnetic attenuation performance. More importantly, a long-rang travelling electron regulation strategy is proposed to switch the electromagnetic function of the Co@C composites between electromagnetic absorption and interference shielding. The optimal electromagnetic wave absorption performance reaches −48.79 dB, and the maximum average electromagnetic interference shielding performance reaches 30 dB. As the simultaneous acquisition of electromagnetic absorption and shielding functions is of great significance for practical applications, patterned design is performed on the surface of the Co@C composites. A perfect electromagnetic resonant absorption band with an absorption coefficient near 1 appears. The patterned Co@C composite features frequency-selective absorption by customizing the geometric parameters of the pattern. This work breaks through the limitations of the single function of traditional electromagnetic nanomaterials and inspires the development of electromagnetic materials towards multiple functions.