Enhanced microwave absorption performance of RGO-modified Co@C nanorods

In this study, Co nanoparticles coated with N-doped carbon films (Co@C) were fabricated using the facile one-pot method. Further, the microwave absorption performance of Co@C prepared at different calcination temperatures was evaluated. When calcinating at 700 °C, the reflection loss values of Co@C are lower than −20 dB with a thickness of 1.5–5.5 mm. The Co particles show enhanced resonation loss with the in situ growth of Co@C on the graphene oxide surface. The presence of reduced graphene oxide (RGO) can prevent agglomeration and reduce the loading content with excellent microwave absorption performance. As expected, the minimum reflection loss of Co@C/RGO reached −44.14 dB when the loading content was only 15% in a paraffin matrix. The considerable microwave absorption performance of this composite can be attributed to the enhanced impedance matching and large interface contact as well as dipolar polarization induced by RGO. This Co@C/RGO composite exhibiting enhanced microwave ability is considered to be an excellent candidate for developing lightweight microwave-absorbing materials.