Nanodiamond@hollow carbon sphere architectures for synergistically enhanced electromagnetic absorption and thermal insulation

Abstract

Carbon materials stood out for electromagnetic absorption due to the lightweight, high-stability and well designability. At present, the research bottleneck lied in achieving broadband absorption and versatility. Novel nanodiamond@hollow carbon sphere architectures were designed in this work, involved with all‑carbon hollow structures and the multiple heterophase interfaces. Bifunctional improvement was realized through the all‑carbon architectures design. Superior electromagnetic wave absorption performance was obtained at an extremely low loading ratio of 5 wt% of the nanodiamond@hollow carbon sphere architectures. With a thickness of 2.15 mm, the optimal reflection loss peak could be −47.1 dB, and the specific absorbing value achieved 438 dBmm−1. Meanwhile, the nanodiamond@hollow carbon sphere architectures exhibited significantly improved thermal insulation characteristics. The simultaneously enhanced electromagnetic absorption and thermal insulation performances were proved to be benefited from the multiple CN hybridizations and the novel all‑carbon hollow hierarchical structures with controllable interfaces. This work serves as a referencing significance for the development of lightweight multi-functional electromagnetic absorbing materials.