Research on electromagnetic absorption performance of graphene/titanium dioxide composites prepared by hydrothermal method

The escalating problem of electromagnetic pollution necessitates the development of efficient, lightweight, and broadband microwave absorbers for both military and civilian applications. While graphene is a promising candidate due to its low density and high electrical conductivity, its standalone use often suffers from impedance mismatch and limited dissipation mechanisms, hindering optimal broadband absorption. To overcome these limitations, strategic hybridization with dielectric materials like titanium dioxide (TiO₂) is pursued to enhance impedance matching and introduce synergistic loss mechanisms. In this study, we employed a hydrothermal method to synthesize composites by depositing TiO₂ coatings on three distinct graphene variants. Characterization revealed that the titanium dioxide-coated reduced graphene oxide (RGO@TiO₂) composite displayed superior microwave absorption performance. Specifically, at a thickness of 2 mm, the composite achieved a minimum reflection loss (RL) of −40.9 dB at 10.3 GHz and an effective absorption bandwidth (RL ≤ −10 dB) of 3.5 GHz. Furthermore, by systematically adjusting the matching layer thickness (1.6–3.2 mm), the composite demonstrated an extended effective absorption bandwidth of 8 GHz, covering the entire X-band. These results indicate that the RGO@TiO₂ composite is a highly promising candidate for broadband electromagnetic absorption, offering significant potential for abating electromagnetic pollution and applications in stealth technology.