In order to achieve an efficient response of the absorber to electromagnetic waves (EMW), vacancy modulation and phase optimization of the composites are crucial. In this study, a phosphorus-doped vacancy modulation and phase interface optimization engineering was designed to prepare nine MOFs-derived metal selenides@carbon double matrix P-doped NiSe₂/CoSe₂@NC (PNCS). The optimal solution of the EMW absorber mechanism was explored by modulating the doping concentration and the calcination temperature. The selection of safeguarded priorities in this work is of constructive significance for the rationalization of EMW absorber preparation is constructive. Upon achieving a ratio of one third of the phosphorus source in the selenide matrix, the calcination temperature of 400 ℃ introduces moderate defects, thus providing the sample with optimal EMW absorption capabilities. With a maximum effective absorption bandwidth of 7.04 GHz at an ultra-thin matching thickness of 2.1 mm. This value covers the entire X and Ku bands within a usable thickness of 2.6 mm, which is significantly superior to other samples of the same type samples. The “dual-core-driven” strategy of heterogeneous interfaces and oxygen vacancies optimizes dielectric relaxation and polarization, supporting a prospective effect on the development and wide application of novel EMW absorbers.

In view of the current serious electromagnetic pollution problem, it is urgent to study efficient electromagnetic wave absorbing materials. The construction of multiphase inhomogeneous interfaces is an effective means, especially for the fine design of multicomponent materials. In this study, multiphase composites with tunable heterogeneous interfaces were prepared by hydrothermal synthesis, carbon coating and high-temperature annealing processes. Multiple component composites constructed rich heterogeneous interfaces, which exhibited strong interfacial polarization effects and effectively improved the absorption efficiency of electromagnetic wave (EMW). The fine tuning of the heterogeneous interfaces is achieved through component adjustment, which enhances the charge carrier transport efficiency and the polarization loss capability. Ultimately, the multiphase VS₂@C@WS₂ composites obtained excellent EMW absorption performance, with the minimum reflection loss and the maximum effective absorption bandwidth of −66.35 dB and 5.12 GHz, respectively. In this work, the controllable construction of heterogeneous interfaces is achieved through the tuning of components, which provides a valuable method for optimizing the polarization loss.

With the accelerating development of electronic technology, how to effectively eliminate electromagnetic radiation pollution has become a critical issue. Electromagnetic wave (EMW) absorption materials have an irreplaceable position in the field of military stealth as well as in the field of electromagnetic pollution control. In order to cope with the complicated electromagnetic environment, the design of multifunctional and multiband high-efficiency EMW absorbers remains a daunting challenge. In this work, a hierarchical porous molybdenum carbide matrix with a three-dimensional porous structure was designed by salt melt synthesis (SMS) strategy. Furthermore, the relationship between the structure and the impedance matching performance was explored by stepwise modification via ultrathin layered MoS₂ nanoflakes. Analysis indicates that the extent of modification of hierarchical porous molybdenum carbide by MoS₂ nanoflakes modulates the dielectric performance due to differences in morphology and the introduction of heterogeneous structures, along with a dramatic impact on the impedance matching performance. In particular, the prepared MS/MC/PNC-2 composite exhibits a reflection loss (RL) of −55.30 dB at 2.4 mm, and an ultra-broad effective absorption bandwidth (EAB) of 7.60 GHz is obtained at 2.0 mm. The coordination of structure and component enables the absorber to exhibit strong absorption, wide bandwidth, thin thickness, and multi-band absorption characteristics. Noticeably, the effective absorption performance in the broadband for X and Ku is also satisfying, as well as possessing moderate marine anti-corrosion performance. This study contributes to an in-depth understanding of the relationship between impedance matching and EMW absorber performance and provides a reference for the design of multifunctional, multiband microwave absorbing materials.

Modern communication systems call for high performance electromagnetic wave absorption materials capable of mitigating microwaves over a wide frequency band. The synergistic effect of structure and component regulation on the electromagnetic wave absorption capacity of materials is considered. In this paper, a new type of three-dimensional porous carbon matrix composite is reported utilizing a reasonable design of surface impedance matching. Specifically, a thin layer of densely arranged Fe-Cr oxide particles is deposited on the surface of porous carbon via thermal reduction to prepare the Fe-Cr-O@PC composites. The effect of Cr doping on the electromagnetic wave absorption performance of the composites and the underlying attenuation mechanism have been uncovered. Consequently, outstanding electromagnetic wave absorption performance has been achieved in the composite, primarily contributed by the enhanced dielectric loss upon Cr doping. Accordingly, an effective absorption bandwidth of 4.08 GHz is achieved at a thickness of 1.4 mm, with a minimum reflection loss value of –52.71 dB. This work not only provides inspiration for the development of novel absorbers with superior performance but also holds significant potential for further advancement and practical application.