Low-dimensional cobalt doped carbon composite towards wideband electromagnetic dissipation

Composites composed of a carbon matrix decorated with a metal or metal oxide derived from zeolitic imidazolate frameworks (ZIFs) have been widely applied as suitable electromagnetic wave absorbers due to their high porosity and controllable morphology. However, achieving ideal absorption performance remains a challenge owing to the inadequate conductivity and high density of the metal components. Therefore, a temperature-controlling treatment was employed for the bimetal ZIFs, and the corresponding derivatives exhibited an excellent dissipation ability with a minimum reflection loss value of −54.3 dB and an effective bandwidth of 7.0 GHz at a thickness of 2.4 mm, which resulted from the strong dipole polarization behavior. Furthermore, after successfully controlling the Zn/Co ratio, the attenuation capability was greatly enhanced at a thickness of 1.4 mm, with bandwidths of 13.0–18.0 GHz. Overall, this work provides an ameliorated strategy for microwave absorption performance of carbon-based materials.