# Preparation and properties of starch-based carbon aerogel/FeCoNi composite wave-absorbing materials

## TL;DR

This paper introduces a new lightweight and eco-friendly material for absorbing electromagnetic waves, using starch and FeCoNi composites with strong absorption performance.

## Contribution

The novel contribution is the development of FeCoNi-doped starch carbon aerogels with enhanced microwave absorption through magnetic-dielectric synergy.

## Key findings

- The material achieved a minimum reflection loss of −60.89 dB at 3 mm thickness.
- The effective absorption bandwidth expanded to 7.91 GHz at 3.5 mm thickness.
- The composite combines a porous structure with magnetic-dielectric synergy for efficient wave absorption.

## Abstract

To address the increasingly serious electromagnetic pollution problem in the era of 6G communication, electromagnetic wave-absorbing materials have gradually become a research focus in modern society. In this work, cassava starch was selected as the precursor, and FeCoNi precipitates were introduced. Starch-based aerogel/FeCoNi composite wave-absorbing materials (FeCoNi/SA) were obtained through sol–gel and freeze-drying processes. Afterward, starch-based carbon aerogel/FeCoNi composite wave-absorbing materials (FeCoNi/SCA) were produced via high-temperature carbonization in a vacuum muffle furnace. The microstructure, chemical features, and wave-absorbing performance of FeCoNi/SCA were examined, and the absorption mechanism was discussed. The results indicated that at a matching thickness of 3 mm, the minimum reflection loss (RLmin) reached −60.89 dB, and the effective absorption bandwidth (EAB) was 6.27 GHz (7.31–13.58 GHz). When the matching thickness increased to 3.5 mm, the EAB expanded to 7.91 GHz (5.61–13.52 GHz). This type of material combines a lightweight porous architecture and a magnetic–dielectric synergistic loss effect, providing a feasible strategy for the development of high-efficiency and environmentally friendly wave-absorbing materials.

FeCoNi-doped starch carbon aerogels achieve superior microwave absorption (RLmin = −60.89 dB, EAB = 7.91 GHz) via magnetic–dielectric synergy, offering a green strategy for efficient electromagnetic attenuation.