A research team led by Professor Wang Guangsheng from the School of Chemistry has made significant progress in the phase transition engineering for electromagnetic wave (EMW) absorbers. Their work, titled "Dielectric Modulation Based on TiO₂ Phase Transition Engineering," has been published in the prestigious journal Advanced Functional Materials.

Doctoral student Bai Yunxia is the first author of the paper, with Professor Wang Guangsheng, Associate Professor Liu Dapeng, and Postdoctoral Fellow Zhao Peiyan serving as corresponding authors.

The rapid advancement of communication technologies has made electromagnetic waves ubiquitous, bringing convenience to daily life and industrial production. However, they also pose challenges to human health and the stable operation of electronic equipment, creating an urgent need for high-performance EMW absorbers. The performance of these materials largely depends on their dielectric properties, yet research on the specific mechanism by which phase transitions regulate dielectric properties remains relatively limited.

This study thoroughly investigatesthe mechanism of phase-change engineering for modulating electromagnetic properties through a strategy of metal doping. Transition metal doped TiO₂ supported on carbon substrates (denoted as C-M/TiO₂, C = carbon, M = Fe, Co, Ni) nanofibers are prepared using a simple electrospinning strategy combined with subsequent thermal treatment. The results show that the phase ratio of rutile-TiO₂ to anatase-TiO₂ can be easily adjusted by varying the type of transition metal dopant, which in turn regulated the conductivity and dielectric properties of the materials. Among the tested metals, Ni doping promoted the formation of a higher proportion of rutile-TiO₂, thereby exerting a more significant effect on the dielectric parameters. Specifically, the optimized C-Ni/TiO₂ sample achieved a minimum reflection loss of −62.2 dB and a maximum effective absorption bandwidth of 6.2 GHz (with a thickness of 2.2 mm).

This work not only provides valuable insights into regulating dielectric parameters via phase transition engineering but also offers important theoretical guidance and potential material solutions for advancing electromagnetic protection in aerospace and telecommunications.

The research was supportedby the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China.

Link to the article: https://doi.org/10.1002/adfm.202526359

Editor: Lyu Xingyun