Rational design of the morphology and structure is important for the functional materials to improve their physicochemical properties. Herein, we design hierarchically three-dimensional (3D) structures assembled with yolk-shelled spheres-supported nitrogen-doped CNTs (NCNTs) using Ni(OH)₂@SiO₂ core-shelled spheres as precursors for electromagnetic wave absorption. In the 3D structures, the yolk materials are SiO₂ spheres, while the shell materials are N-doped carbon layers containing Ni, Si and O elements. Importantly, The NCNT arrays with encapsulated Ni NPs are branched out from the yolk-shelled spheres. The hierarchical structures feature the merits of both yolk-shelled and 3D structures. Furthermore, the SiO₂ sphere in the 3D structure can tune the electrical conductivity, affording our hierarchically 3D structure better impedance matching characteristic for electromagnetic wave absorption. As a result, the reflection loss and effective absorption bandwidth of our optimal 3D structure can reach −59.90 dB and 4.24 GHz, respectively, while the thickness of the absorbing film is only 1.4 mm, superior to most of reported carbon-based absorbers. The present method for the regulation of the structure and morphology provides an efficient way to construction of high-performance electromagnetic wave absorbers.

形态结构的合理设计对于功能材料改善其理化性能具有重要意义。在此，我们使用 Ni(OH) ₂ @SiO ₂核壳球体作为电磁波吸收的前体，设计了由蛋黄壳球体支撑的氮掺杂碳纳米管 (NCNTs) 组装而成的分层三维 (3D) 结构。在3D结构中，蛋黄材料是SiO ₂球体，而壳材料是含有Ni、Si和O元素的N掺杂碳层。重要的是，带有封装 Ni NPs 的 NCNT 阵列是从蛋黄壳球体中分支出来的。分层结构具有蛋黄壳结构和 3D 结构的优点。此外，SiO ₂3D 结构中的球体可以调节电导率，为我们的分层 3D 结构提供更好的电磁波吸收阻抗匹配特性。因此，我们优化的 3D 结构的反射损耗和有效吸收带宽分别可以达到 -59.90 dB 和 4.24 GHz，而吸收膜的厚度仅为 1.4 mm，优于大多数报道的碳基吸收剂。本发明的结构和形态调节方法为构建高性能电磁波吸收器提供了一种有效的方法。