Fabrication and enhanced electromagnetic wave absorption properties of sandwich-like graphene@NiO@PANI decorated with Ag particles

The fabrication of sandwich graphene@NiO@PANI decorated with Ag particles was successfully carried out using multi-step method. A facile hydrothermal route (graphene@Ni(OH)2) was used in the first step, and calcination of precursor by tube furnace (graphene@NiO) in second step, followed using a situ polymerization (graphene@NiO@PANI), and finally formation of the quaternary composite (graphene@NiO@PANI@Ag) via reduction of AgNO3. The obtained samples were analyzed by kinds of instruments and the electromagnetic parameters demonstrated that the improving EM absorption property (−37.5 dB) of graphene@NiO@PANI@Ag was ascribed to the better attenuation constant, impedance matching and enhanced interfacial effects. For graphene@NiO@PANI@Ag, the maximum reflection loss was up to −37.5 dB at 13.4 GHz, and bandwidth exceeding −10 dB was 4.9 GHz for a thickness of 3.5 mm. Thus, the graphene@ NiO@PANI@Ag composite, with a high EM absorption performance and wide absorbing bandwidth, is a promising microwave absorbent.