Currently, as the electromagnetic (EM) environment becomes increasingly complex, single-function EM materials can hardly resist the increasing electromagnetic interference (EMI), and there is an urgent need to develop multifunctional EM materials. In this work, multifunctional WSe₂/Co₃C was prepared by simple hydrothermal methods. Its dielectric performance and EM response were investigated. Efficient absorption, shielding performance, and energy conversion devices were customized. By tailoring the loading content, WSe₂/Co₃C can switch between EM absorption and EMI shielding. The maximum shielding effectiveness (SE) of WSe₂/Co₃C reached 36 dB, and high reflection loss (RL) of −60.28 dB and wide effective absorption bandwidth (EAB) of 6.16 GHz can be obtained at low thickness. The multiple EM attenuation mechanisms brought by the combination of two-dimensional (2D) WSe₂ and magnetic Co₃C are considered to be the main reason for the enhanced EM attenuation ability. The WSe₂/Co₃C composite provides a viable candidate for developing multifunctional EM materials in 2–18 GHz.

Dedicating to the exploration of efficient electromagnetic (EM) absorption and electromagnetic interference (EMI) shielding materials is the main strategy to solve the EM radiation issues. The development of multifunction EM attenuation materials that are compatible together EM absorption and EMI shielding properties is deserved our exploration and study. Here, the graphene-wrapped multiloculated NiFe₂O₄ composites are reported as multifunction EM absorbing and EMI shielding materials. The conductive networks configurated by the overlapping flexible graphene promote the riched polarization genes, as well as electron transmission paths, and thus optimize the dielectric constant of the composites. Meanwhile, the introduction of magnetic NiFe₂O₄ further establishes the magnetic-dielectric synergy effect. The abundant non-homogeneous interfaces not only generate effective interfacial polarization, also the deliberate multiloculated structure of NiFe₂O₄ strengthens multi-scattering and multi-reflection sites to expand the transmission path of EM waves. As it turns out, the best impedance matching is matched at a lower filled concentration to achieve the strongest reflection loss value of −48.1 dB. Simultaneously, green EMI shielding based on a predominantly EM absorption and dissipation is achieved by an enlargement of the filled concentration, which is helpful to reduce the secondary EM wave reflection pollution to the environment. In addition, the electrocatalytic properties are further examined. The graphene-wrapped multiloculated NiFe₂O₄ shows the well electrocatalytic activity as electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), which is mainly attributed to the interconnected structures formed by graphene and NiFe₂O₄ connection. The structural advantages of multiloculated NiFe₂O₄ expose more active sites, which plays an important role in optimizing catalytic reactions. This work provides an excellent jumping-off point for the development of multifunction EM absorbing materials, eco-friendliness EMI shielding materials and electrocatalysts.

High efficiency microwave absorption (MA) materials with tunable electromagnetic (EM) features have been highly sought. However, it is still a challenge to achieve multi-bands absorption performance by simple optimizing the chemical composition of MA materials. Herein, a simple solvothermal method was used to embed magnetic Fe₃O₄ nanoclusters on MoS₂ nanosheets, in which magnetic nanoclusters were quantitatively customized. More importantly, the MA frequency and MA properties of the material are highly tailored, and multi-bands absorption is achieved. The minimum reflection loss (RL) of Fe₃O₄/MoS₂ composite reaches −87.24 dB and is about 4 times more than pure MoS₂ nanosheets. The effective absorption bandwidth reaches 5.52 GHz (≤-10 dB). These desirable properties result from the introduction of appropriate magnetic Fe₃O₄ nanoclusters, which provide optimal synergistic effect of dielectric and magnetic losses. This result provides a feasible idea for designing high efficiency MA materials with tunable EM features in the future.

Flexible and wearable electromagnetic interference (EMI) shielding material is one of the current research focuses in the field of EMI shielding. In this work, for the first time, WS₂-carbon fiber (WS₂-CF) composites are synthesized by implanting WS₂, which has a multiphase structure and a large number of defects, onto the surface of carbon fiber (CF) by using a simple one-step hydrothermal method, and are applied to protect electronic devices from EMI. It is found that the EMI shielding performance of WS₂-CF is significantly improved, especially for those at S— and C-bands. At 2 GHz, the EMI shielding efficiency could reach 36.0 dB at a typical thickness of 3.00 mm of the composite, which is much better than that of pure CF (25.5 dB). Besides paving a novel avenue to optimize the electromagnetic shielding performance of flexible and wearable CF-based EMI shielding materials, which have great potential in the practical application for EMI shielding, this work provides a new paradigm for the design and synthesis of EMI shielding materials which have a broad application prospect.

Lightweight and high-efficiency microwave absorption materials with tunable electromagnetic properties is a highly sought-after goal and a great challenge for researchers. In this work, a simple strategy of confinedly implanting small NiFe₂O₄ clusters on reduced graphene oxide is demonstrated, wherein the magnetic clusters are tailored, and more significantly, the electromagnetic properties are highly tuned. The microwave absorption was efficiently optimized yielding a maximum reflection loss of –58 dB and ~12 times broadening of the bandwidth (at –10 dB). Furthermore, tailoring of the implanted magnetic clusters successfully realized the selective-frequency microwave absorption, and the absorption peak could shift from 4.6 to 16 GHz covering 72% of the measured frequency range. The fascinating performances eventuate from the appropriately tailored clusters, which provide optimal synergistic effects of the dielectric and magnetic loss caused by multi-relaxation, conductance, and resonances. These findings open new avenues for designing microwave absorption materials in future, and the well-tailored NiFe₂O₄-rGO can be readily applied as a multi-functional microwave absorption material in various fields ranging from civil and commerce to military and aerospace.

In this work, atomic layer deposition (ALD) was employed to fabricate coaxial multi-interface hollow Ni-Al₂O₃-ZnO nanowires. The morphology, microstructure, and ZnO shell thickness dependent electromagnetic and microwave absorbing properties of these Ni-Al₂O₃-ZnO nanowires were characterized. Excellent microwave absorbing properties with a minimum reflection loss (RL) of approximately –50 dB at 9.44 GHz were found for the Ni-Al₂O₃-100ZnO nanowires, which was 10 times of Ni-Al₂O₃ nanowires. The microwave absorption frequency could be effectively varied by simply adjusting the number of ZnO deposition cycles. The absorption peaks of Ni-Al₂O₃-100ZnO and Ni-Al₂O₃-150ZnO nanowires shifted of 5.5 and 6.8 GHz towards lower frequencies, respectively, occupying one third of the investigated frequency band. The enhanced microwave absorption arose from multiple loss mechanisms caused by the unique coaxial multi-interface structure, such as multi-interfacial polarization relaxation, natural and exchange resonances, as well as multiple internal reflections and scattering. These results demonstrate that the ALD method can be used to realize tailored nanoscale structures, making it a highly promising method for obtaining high- efficiency microwave absorbers, and opening a potentially novel route for frequency adjustment and microwave imaging fields.