Fe-Biomass Carbon Aerogels Combine Conductive and Magnetic Properties

Biomass-derived carbon aerogels infused with iron combined a hierarchical porous structure, low electrical resistivity and magnetic behavior in a materials study aimed at energy-storage and electromagnetic-shielding applications. The optimized formulation, designated CS/CMC-50%-C and produced from chitosan and sodium carboxymethyl cellulose, reached a resistivity of 0.454 Ω·cm and a specific surface area of 458.9 m²·g⁻¹. It also retained stable electrical conductivity and integral structural integrity through ten consecutive charge–discharge cycles.

The researchers fabricated the aerogels through a multistep process beginning with Fe³⁺-mediated coordination cross-linking of the two biomass precursors. Directional freeze-drying created a high-porosity precursor aerogel, which was then carbonized at high temperature. This sequence allowed the investigators to regulate the material’s microscopic morphology and electrical properties by varying the precursor ratio. The optimized material formed a well-developed hierarchical porous architecture and exhibited a higher degree of graphitization, factors associated with its performance as a lightweight conductive solid.

Iron served both a structural and functional role during carbonization. The process generated Fe₃O₄ nanocrystals in situ, while also producing Fe–C bonds. Together, these features imparted favorable magnetic behavior to the carbon aerogel and reinforced the interconnections within its internal conductive network. In other words, the iron-containing phase did more than add magnetism: its integration into the carbon matrix was linked to preservation of electrical transport pathways. The reported findings therefore demonstrate coupled magnetic and electrical characteristics rather than merely showing that iron was physically mixed into a carbon framework.

Directional freezing and Fe³⁺ cross-linking were central to controlling the precursor’s structure before carbonization, and the study indicates that the balance between chitosan and carboxymethyl cellulose influenced the final morphology and conductivity. The reported 458.9 m²·g⁻¹ surface area, low resistivity and three-dimensional porous network make the optimized aerogel a promising candidate for lightweight electromagnetic-shielding and energy-storage materials. The ten-cycle result also provides an initial indication of electrical and structural stability under repeated charge–discharge operation, although the supplied findings do not establish long-term cycling durability or performance under practical operating conditions.

Subject of Research: Fabrication and characterization of magnetic conductive carbon aerogels derived from iron-cross-linked chitosan and carboxymethyl cellulose.

Article Title: Structural regulation and coupled electrical-magnetic properties of biomass-derived Fe-incorporated carbon aerogels

Article References: Xu, Y., Huang, L., Hu, D., Ke, Y., Li, H., Yang, J., Fu, B., Zhao, H., Sha, L., Sun, M., & Yuan, T. (2026). Structural regulation and coupled electrical-magnetic properties of biomass-derived Fe-incorporated carbon aerogels. Journal of Materials Science, 61(40), 30916-30934. https://doi.org/10.1007/s10853-026-13634-7

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13634-7

Keywords: biomass-derived aerogels, chitosan, carboxymethyl cellulose, iron nanoparticles, Fe₃O₄, carbon aerogels, electrical conductivity, magnetic materials, porous carbon, energy-storage materials, Structural, regulation