Electromagnetic wave absorbing properties of In–Sn/rGO composites supported by impurity defect

With the fast development of E-communication technology, effective electromagnetic wave absorbing materials are highly needed to address the growing electromagnetic pollution. Herein, Indium doped tin microsphere/reduced graphene oxide (In–Sn/rGO) composites with rich impurity defects were synthesized via the sol-gel and hydrothermal method. The excellent microwave absorption of In–Sn/rGO composites can be attributed to the modifications of electronics status and Fermi energy level after In doping. This can significantly increase the carrier mobility between In–Sn microspheres and rGO sheets to strike a superior interfacial polarization loss. As a result, the maximum absorptivity can reach ?51.16 dB at 8.73 GHz (thickness: 3.5 mm) with a lower filler loading of 10 wt%. Meanwhile, the synthesized In–Sn/rGO composites also exhibit an ultra-wide absorbing frequency range of 13.84 GHz (within the X band, Ku band, and most of the C band). This research provides a new idea for the synthesis of effective microwave absorbing material by introducing impurity defects.