Herein, the advances in low-dimensional core-shell EM wave absorption materials are outlined and a selection of the most remarkable examples is discussed. The derived key information regarding dimensional design, structural engineering, performance, and structure-function relationship are comprehensively summarized. Moreover, the investigation of the cuttingedge mechanisms is given particular attention. Additional applications, such as oxidation resistance and self-cleaning functions, are also introduced. Finally, insight into what may be expected from this rapidly expanding field and future challenges are presented.

Rational designing of one-dimensional (1D) magnetic alloy to facilitate electromagnetic (EM) wave attenuation capability in low-frequency (2–6 GHz) microwave absorption field is highly desired but remains a significant challenge. In this study, a composite EM wave absorber made of a FeCoNi medium-entropy alloy embedded in a 1D carbon matrix framework is rationally designed through an improved electrospinning method. The 1D-shaped FeCoNi alloy embedded composite demonstrates the high-density and continuous magnetic network using off-axis electronic holography technique, indicating the excellent magnetic loss ability under an external EM field. Then, the in-depth analysis shows that many factors, including 1D anisotropy and intrinsic physical features of the magnetic medium-entropy alloy, primarily contribute to the enhanced EM wave absorption performance. Therefore, the fabricated EM wave absorber shows an increasing effective absorption band of 1.3 GHz in the low-frequency electromagnetic field at an ultrathin thickness of 2 mm. Thus, this study opens up a new method for the design and preparation of high-performance 1D magnetic EM absorbers.

structure and chemical variety endow MXene with many attractive properties such as high intrinsic conductivity, large specific surface, high electron mobility, mechanical stability, abundant surface functional groups, and defects. [10] However, it is urgent to ameliorate the excessive permittivity and conductivity of MXene, promoting it to be competitive and promising microwave absorbers.To solve serious electromagnetic pollution radiated out from high-power popularized 5G commutation network, MA have been attracted extensive interest. [11] Characteristic impedance matching becomes a key issue responsible for high microwave energy attenuation capacity. MXene with 2D anisotropy holds powerful potential as the lightweight MA material due to its relatively low percolation threshold. [12] However, restricted by the excessive conductivity and permittivity, MXene obtains improper impedance matching and thereby weak microwave absorbing property. [13] Dielectric property engineering through compositing [14][15][16] and heterojunction design [17,18] have been widely applied to address the above obstacles. The bi-components with specially designed interfaces can effectively manage the dielectric property in terms of conduction and polarization behavior, such as, Ti 3 C 2 T x MXene/carbon nanotubes (CNTs). [19] Besides, the design of the microstructure plays an important role in the improvement of impedance matching and microwave performance. Constructing 2D nanosheets into 3D hierarchical network is an effective method to provides the larger specific surface area and higher porosity. [20] Hollow and porous structures bring more scattering and reflection sites, resulting in the enhanced MA. [21] However, the traditional preparation method focused on the electrostatic adsorption [22,23] and vacuum-assisted filtration, [24,25] which cannot effectively control the morphology of composite. The weak connection and high contact resistance between Ti 3 C 2 T x and CNTs also hinder the extended application. [26] Dielectric-magnetic synergy is also an effective strategy to achieve appropriate impedance matching of MA material. [27][28][29] Magnetized MXene hybrid materials enhance microwave attenuation by the synergistic effect of dielectric dissipation and Hierarchical hollow structure with unique interfacial properties holds great potential for microwave absorption (MA). Ti 3 C 2 T x MXene has been a hot topic due to rich interface structure, abundant defects, and functional groups. However, its overhigh permittivity and poor aggregation-resistance limit the further application. Herein, a hierarchical MXene-based hollow microsphere is prepared via a facile spray drying strategy. Within the microsphere, few-layered MXene nanosheets are separated by dispersed carbon nanotubes (CNTs), exposing abundant dielectric polarization interfaces. Besides, numerous magnetic Fe 3 O 4 nanospheres are uniformly dispersed and confined within nano-cavities between 1D network and 2D framework. Such a novel structure simultaneously promotes interfaci...

Structural engineering via the template method is efficient for micro‐nano assembling. However, only structural design and lack of composition control restrict their advanced application. To overcome this issue, applying a template to simultaneously realize the structural design and fine component control is highly desired, which has been ignored. In this study, a spinel‐shaped MoS2 heterostructure with controlled phase ratios of 1H and 2H phase is developed using the AlOOH template method. This work demonstrates that the MoS2 phase transition mechanism from 2H to 1T is substantially attributed to the close exposed crystal's surface and approximately accordant surface energy. The superiority and additional proof are provided based on density‐functional theory simulation, transmission electron microscope holography, etc. With an effective absorptance region of 6.3 GHz under a thickness of 1.4 mm, the reported samples present outstanding microwave absorption capacity. This is attributed to the beneficial coupled effect between the well‐designed structure and phase regulation. This work offers valuable insights into structural engineering and component regulation template methods.