Research progress on spherical carbon-based electromagnetic wave absorbing composites

Electromagnetic waves constitute an essential element of societal progress, and the environmental impact resulting from using electromagnetic waves warrants significant considerations. Carbon materials have garnered considerable attention in the functional domain owing to their remarkable electrical conductivity and dielectric characteristics. Notably, spherical carbon materials, characterized by their substantial specific surface area and tunable dielectric properties, have emerged as efficient additives for microwave absorbers. These materials excel in absorbing electromagnetic energy while minimizing energy dissipation. When incorporated into absorbers of varying compositions, sizes, and morphologies, these carbon spheres facilitate the synergistic operation of multiple loss mechanisms, containing conductive loss, magnetic loss, and polarization loss. This concerted action significantly enhances the electromagnetic wave absorption performance. This paper offers a comprehensive review of the advancements in carbon sphere-based materials designed for absorbing electromagnetic waves. It also furnishes an intricate exposition of the methodologies employed in their preparation and a meticulous analysis of their performance. The paper summarizes the microstructural attributes and mechanisms governing electromagnetic wave absorption in various carbon sphere configurations, considering factors such as composition, morphology, size, and structure. In conclusion, this study forecasts the potentials of carbon sphere-based nanomaterials in the realm of electromagnetic waves, along with an assessment of forthcoming research focal points and conceivable challenges.