Homogeneous heterogeneous (heterophase) interfaces regulated with low energy barriers have a fast response to applied electric fields and could provide a unique interfacial polarization, which facilitate the transport of electrons across the substrate. Such regulation on the interfaces is effective in modulating electromagnetic wave absorbing materials. Herein, we construct NbS₂–NiS₂ heterostructures with NiS₂ nanoparticles uniformly grown in NbS₂ hollow nanospheres, and such particular structure enhances the interfacial polarization. The strong electron transfer at the interface promotes electron transport throughout the material, which results in less scattering, promotes conduct ion loss and dielectric polarization relaxation, improves dielectric loss, and results in a good impedance matching of the material. Consequently, the absorbing band may be successful tuned. By regulating the amount of NiS₂, the heterogeneous interface is finely alternated so that the overall wave-absorbing performance is shifted to lower frequencies. With a NiS₂ content of 15 ​wt% and an absorber thickness of 1.84 ​mm, the minimum reflection loss at 14.56 ​GHz is −53.1 ​dB, and the effective absorption bandwidth is 5.04 ​GHz; more importantly, the minimum reflection loss in different bands is −20 dB, and the microwave energy absorption rate reaches 99% when the thickness is about 1.5–4.5 ​mm. This work demonstrates the construction of homogeneous heterostructures is effective in improving the electromagnetic absorption properties, providing guideline for the synthesis of highly efficient electromagnetic absorbing materials.

As electromagnetic technology advances and demand for electronic devices grows, concerns about electromagnetic pollution intensify. This has spurred focused research on innovative electromagnetic absorbers, particularly chalcogenides, noted for their superior absorption capabilities. In this study, we successfully synthesize 3R–TaS₂ nanosheets using a straightforward calcination method for the first time. These nanosheets exhibit significant absorption capabilities in both the C-band (4–8 ​GHz) and Ku-band (12–18 ​GHz) frequency ranges. By optimizing the calcination process, the complex permittivity of TaS₂ is enhanced, specifically for those synthesized at 1000 ​℃ for 24 ​h. The nanosheets possess dual-band absorption properties, with a notable minimum reflection loss (RL_min) of −41.4 ​dB in the C-band, and an average absorption intensity exceeding 10 ​dB in C- and Ku-bands, in the absorbers with a thickness of 5.6 ​mm. Additionally, the 3R–TaS₂ nanosheets are demonstrated to have an effective absorption bandwidth of 5.04 ​GHz (3.84–8.88 ​GHz) in the absorbers with thicknesses of 3.5–5.5 ​mm. The results highlight the multiple reflection effects in 3R–TaS₂ as caused by their stacked structures, which could be promising low-frequency absorbers.

Although VB-Group transition metal disulfides (TMDs) VS₂ nanomaterials with specific electronic properties and multiphase microstructures have shown fascinating potential in the field of electromagnetic wave (EMW) absorption, the efficient utilization of VS₂ is limited by the technical bottleneck of its narrow effective absorption bandwidth (EAB) which is attributed to environmental instability and a deficient electromagnetic (EM) loss mechanism. In order to fully exploit the maximal utilization values of VS₂ nanomaterials for EMW absorption through mitigating the chemical instability and optimizing the EM parameters, biomass-based glucose derived carbon (GDC) like sugar-coating has been decorated on the surface of stacked VS₂ nanosheets via a facile hydrothermal method, followed by high-temperature carbonization. As a result, the modulation of doping amount of glucose injection solution (Glucose) could effectively manipulate the encapsulation degree of GDC coating on VS₂ nanosheets, further implementing the EM response mechanisms of the VS₂/GDC hybrids (coupling effect of conductive loss, interfacial polarization, relaxation, dipole polarization, defect engineering and multiple reflections and absorptions) through regulating the conductivity and constructing multi-interface heterostructures, as reflected by the enhanced EMW absorption performance to a great extent. The minimum reflection loss (R_min) of VS₂/GDC hybrids could reach −52.8 dB with a thickness of 2.7 mm at 12.2 GHz. Surprisingly, compared with pristine VS₂, the EAB of the VS₂/GDC hybrids increased from 2.0 to 5.7 GHz, while their environmental stability was effectively enhanced by virtue of GDC doping. Obviously, this work provides a promising candidate to realize frequency band tunability of EMW absorbers with exceptional performance and environmental stability.