Microwave absorption enhancement and loss mechanism of lamellar MnO₂ nanosheets decorated reduced graphene oxide hybrid

Manganese oxide/reduced graphene oxide (MnO₂/rGO) hybrid with layered MnO₂ nanosheets grow on rGO surfaces have been prepared for microwave absorbing. The hybrid exhibits significantly enhanced microwave absorption properties compared with rGO and MnO₂. A maximum reflection loss value can reach − 26.7 dB at 11.04 GHz with the matching thickness of 2.6 mm, and the effective absorption bandwidths exceeding − 10 dB and − 20 dB are 3.6 GHz and 1.06 GHz, respectively. The enhancement in microwave absorption efficiency of MnO₂/rGO hybrid is arose from the synergistic effects between lamellar MnO₂ and rGO in its unique three-dimensional (3D) architecture, which leads to strong conduction loss and multiple reflections, and further in favour of appropriate impedance matching ratio and good attenuation ability. These fundamental understandings on the property–structure relationship of as-synthesized MnO₂/rGO hybrid will prove an efficient approach to the designing and construction of MnO₂-based 3D nanostructures for advanced electromagnetic wave absorbing applications.