Optimized impedance matching of micro-porous silicon dioxide coated graphite nanosheets as remarkable microwave absorber

Despite the high electromagnetic wave (EMW) attenuation capabilities, graphite nanosheets (GNs) are still facing great challenges as absorbing material owing to the strong reflection. Herein, a porous silicon dioxide coated GNs (PSi@GNs) is designed by sol–gel reaction to optimize the impedance matching of GNs. The coated porous SiO2 can not only balance the impedance between GNs and air, preventing the EMW reflection, but also increase the interfacial polarization behavior and benefit polarization loss. As a result, the as-synthesized SiO2/GNs exhibits superior EMW absorption performances with the minimum reflection loss (RL) value of −59.835 dB and effective absorbing bandwidth (EAB) of 3.36 GHz at 3.22 mm (25% filled). The advantages of the PSi@GNs potential applications in military radar, electronic communication, weapons and other fields.