Multidimensional Co‐Design and Performance‐Mechanism Study of Novel Graphdiyne Composites with Microwave Absorbing Structures

Abstract Graphdiyne (GDY), an emerging member in the carbon material family, possesses abundant chemical bonds, extended conjugated systems, and superior charge carrier mobility, establishing it as a promising novel microwave absorption material. Capitalizing on these attributes, in this work, a flower‐like GDY@Cu₂O composite with a unique nanowall structure is prepared by a one‐step microemulsion method. Remarkably, temperature‐mediated enhancement of electron transport coupled with induced multipolarization synergistically boosts the microwave absorption performance. The optimal specimen (GDY@Cu₂O‐700) achieves an effective absorption bandwidth (EAB) of 6.1 GHz at 2.2 mm matched thickness, with a minimum reflection loss of −49.9 dB@17.7 GHz. Furthermore, a metamaterial is designed at the millimeter scale using GDY@Cu₂O‐700 as the microwave absorbing functional component. Following optimization via 3D electromagnetic simulation software, this metamaterial demonstrates an ultra‐broad EAB spanning 34.1 GHz in the range of 2–40 GHz. This pioneering study delineates the electromagnetic wave absorption characteristics of GDY‐based microspheres with GDY as the primary constituent and provides a valuable reference for designing innovative wave‐absorbing materials.