Construction of Co3O4 porous rod/graphene heterostructures toward strong and broadband microwave absorption applications

Microwave absorbing materials (MAMs) are of paramount importance to address electromagnetic radiation pollution concerns. However, the development of MAMs with strong absorption, broadband and good impedance matching features still faces challenges. Herein, a compositional and structural engineering strategy is proposed to tailor the polarization and multiple reflection and scattering characteristics, and the Co3O4 porous rod/graphene (Co3O4 PR/G) heterostructures are constructed. The porous rod structure of Co3O4 and plentiful heterointerfaces between Co3O4 and graphene generate massive microwave attenuation paths and promote the interfacial polarization, resulting in improved microwave attenuation. The Co3O4 PR/G heterostructures exhibit the minimum reflection loss of −49.1 dB and effective absorption bandwidth of 9.3 GHz, overpowering many similar reported microwave absorbers. This work is a new attempt for the development of advanced MAMs with strong absorption and broad bandwidth characteristics, which provides an effective compositional-structural regulating strategy to promote microwave absorption.