Boron carbide (B₄C) is normally known as a structural ceramic with excellent mechanical properties. Herein, the application of graphene-layer-coated B₄C nanosheets (B₄C@GN NSs) as efficient electromagnetic (EM) wave absorption materials was reported for the first time. B₄C@GN NSs grew via the vapor–solid (VS) mechanism and coated with an ultrathin graphene layer through annealing. In addition to its graphene shell, the B₄C@GN NSs had a unique small-sized nanosheet structure with a single sheet thickness of less than 50 nm. Concurrently, B₄C micro- and nanoparticles were purchased or prepared to compare the morphologies and performances of several kinds of different B₄C materials via characterization and analyses. The comparison revealed that the novel B₄C@GN NSs possessed a special structure and a unique graphene shell that led to the great improvement in EM wave absorption. With a thickness of 1.19 mm, the B₄C@GN NSs exhibited a minimal reflection loss (RL_min) of − 24.6 dB and a broad effective absorption bandwidth of 3.9 GHz. The electronic structure was analyzed by XANES to clarify the mechanism. The above results proved B₄C@GN NSs to be an expectant absorber. The development of B₄C@GN NSs might lay a theoretical foundation for the functionalization of structural ceramic materials.

碳化硼（B ₄ C）通常被称为具有优异机械性能的结构陶瓷。在此，首次报道了石墨烯层包覆的B ₄ C纳米片（B ₄ C @ GN NSs）作为有效的电磁波吸收材料的应用。B ₄ C @ GN NSs通过气固（VS）机理生长，并通过退火涂覆了超薄石墨烯层。除了其石墨烯壳外，B ₄ C @ GN NSs还具有独特的小尺寸纳米片结构，单片厚度小于50 nm。同时，购买或准备了B ₄ C微粒和纳米颗粒，以比较几种不同B ₄ C的形貌和性能通过表征和分析获得C材料。比较表明，新型的B ₄ C @ GN NS具有特殊的结构和独特的石墨烯壳，导致电磁波吸收大大改善。B ₄ C @ GN NS的厚度为1.19毫米，反射损耗（RL _min）为-24.6 dB，_最小，有效吸收带宽为3.9 GHz。XANES对电子结构进行了分析，以阐明其机理。以上结果证明了B ₄ C @ GN NSs是预期的吸收剂。B ₄ C @ GN NSs的发展可能为结构陶瓷材料的功能化奠定理论基础。