Electrostatic self-assembled CS/Ti3C2Tx/Co@CNTs composites with gradient carbon structure and wideband microwave absorption

In July 2025, researchers including Li Tianshuo from the High Temperature Electromagnetic Materials Team of Wuhan University of Science and Technology published their latest findings in "Nano Research", reporting a three-dimensional gradient carbon structure electromagnetic wave absorption material (CS/Ti₃C₂T_x/Co@CNTs) prepared by electrostatic self-assembly. This material achieves a minimum reflection loss of -55.01 dB and an effective absorption bandwidth of 9.07 GHz with an ultra-low density of only 0.03 g/cm³, providing a new solution for electromagnetic protection of 5G communication equipment.

The research team utilized the principle of positive and negative charge attraction to anchor the two-dimensional Ti₃C₂T_x MXene layers onto the carbon framework derived from melamine sponge (CS), and through the catalytic in-situ growth of carbon nanotubes by cobalt nanoparticles (Co@CNTs), they constructed a hierarchical structure of "carbon framework - MXene - core-shell carbon nanotubes". Electron microscopy analysis revealed that the Ti₃C₂T_x layers effectively blocked the carbon framework pores, forming multiple electromagnetic wave reflection surfaces. The carbon nanotubes with diameter differences grow on the MXene and carbon framework, resulting in rich hetero interfaces such as Co-CNTs and CNT-Ti₃C₂T_x. This structure effectively improves the impedance matching problem of the MXene material.

The electromagnetic performance tests indicate that the advantages of this material stem from a triple synergy mechanism:

1. Conductive loss: the three-dimensional carbon network forms a continuous conductive path with CNTs, converting electromagnetic energy into Joule heat.

2. Interface polarization: the accumulation of charges at the heterojunction leads to polarization loss under an alternating electric field.

3. Multiple Reflection: The large-sized MXene layers construct an electromagnetic wave "maze" effect within the material.

Compared with the MXene-based absorbing materials reported in recent years, this material exhibits outstanding comprehensive performance at a 10% filling rate. Its effective absorption bandwidth covers the C to X bands (4 - 18 GHz), and the absorption intensity at a thickness of 3.4 mm exceeds that of most similar materials. This electrostatic self-assembly strategy has solved the impedance mismatch problem caused by the high electrical conductivity of MXene, opening up a new path for lightweight electromagnetic protection in aerospace and integrated circuits.

This work is supported by Nation Natural Science Foundation of China (Grant Nos. 52304410 and 51972242), the Major Project of Hubei Province (Functional coating and materials, 2023BAA003) and the Young Top-notch Talent Cultivation Program.

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 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 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.