Facile process for cost-effective layer-by-layer rGO/SiO2 structure for high microwave absorption

Abstract

This study introduces a cost-effective and eco-efficient method for fabricating an advanced microwave absorber using a layer-by-layer rGO and SiO2 structure. The rGO/SiO2 composite, synthesized via modified Hummer's and Stöber methods, demonstrates remarkable microwave absorption properties. The resultant porous structure, characterized by an SBET of 294.89 m2/g, enables multiple reflections and scatterings of electromagnetic waves. At a sample thickness of 3.8 mm, the material achieves a reflection loss (RL) of −47.43 dB at 12.56 GHz and an effective absorption bandwidth (EAB) of 11.04 GHz. For a 6 mm thick sample, an exceptionally high EAB of 12.72 GHz is observed, maintaining a high RL of −42.32 dB. These results demonstrate that the rGO/SiO2 material is a promising candidate for applications in electromagnetic wave absorption, offering a simple, scalable solution for mitigating electromagnetic pollution and enhancing military stealth technologies.