In today's world, wireless devices such as mobile phones, routers, and smart terminals are deeply integrated into daily life. The accompanying electromagnetic radiation not only interferes with the operation of precision electronic instruments but may also pose potential risks to human health. Developing materials that can efficiently absorb electromagnetic waves has become key to addressing this issue.
However, traditional EMW absorption materials have long faced a fundamental bottleneck: materials like carbon-based ones often have high reflectivity, preventing waves from penetrating effectively, while metal-based materials struggle with impedance mismatch, hindering efficient energy dissipation. "It's like a container that needs to both let the electromagnetic waves 'enter the door' smoothly and ensure they are 'consumed entirely' inside. Balancing these two aspects is exceptionally challenging," explained Associate Professor Zirui Jia.
To overcome this dilemma, the Qingdao University team proposed a unique "heterointerface-defect synergy" design approach. Using solvothermal-electrospinning technology, they combined CoS2 and NiS2 sulfides with hollow carbon nanofibers (HCNFs) to create a composite material with a gradient electronic structure.
The ingenuity of this design lies in its dual synergistic effects: Firstly, the heterointerface formed between CoS2 and NiS2 generates a strong built-in electric field, driving directional charge transfer and facilitating the rapid conversion of electromagnetic energy into heat for dissipation. Secondly, intentionally introduced sulfur vacancies act as "energy traps," coupling with the built-in electric field to further enhance EMW absorption loss. Concurrently, the three-dimensional network structure of the hollow carbon nanofibers not only optimizes impedance matching for efficient wave entry but also prolongs the propagation path of the waves, boosting absorption efficiency.
Experimental data reveal the exceptional performance of the optimized CoS2/NiS2@HCNFs composite: At a minimal thickness of 2.6 mm, the effective absorption bandwidth (EAB) covers 8.32 to 18.4 GHz, encompassing the entire X-band (8-12 GHz) and Ku-band (12-18 GHz). At a thickness of 2.4 mm, the minimum reflection loss (RLmin) reaches -48.04 dB, meaning over 99.99% of the incident electromagnetic wave energy is absorbed. Compared to single-metal sulfide systems, the EAB is increased by 61%. Furthermore, even with a low filler loading of 15 wt%, the material maintains excellent absorption performance at a 60° oblique incidence.
These findings have been published in the journal Nano Research on May 14.
"This composite material combines the advantages of being lightweight, broadband, and highly lossy, making it suitable for a wide range of applications," said Professor Guanglei Wu. In civilian sectors, it can be used for electromagnetic shielding in 5G base stations and electronic devices to reduce radiation pollution. In the military field, it could serve as a core material for stealth equipment, lowering radar detection probability.
The team stated that their next steps will focus on optimizing the large-scale production process to reduce costs and exploring its application in low-frequency EMW absorption scenarios, aiming to translate this innovation into practical use more rapidly.
This research received support from the National Natural Science Foundation of China (No.52377026 and No. 52301192), the Taishan Scholars and Young Experts Program of Shandong Province (No. tsqn202103057), the Natural Science Foundation of Shandong Province (No. ZR2024ME046 and No. ZR2024QE313), and the Postdoctoral Science Foundation of China (No. 2024M761554).
DOI Link:
https://doi.org/10.26599/NR.2026.94908411
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
