Carboxymethyl cellulose/tea polyphenol/polypyrrole-derived carbon aerogel for electromagnetic wave absorption

A green route is developed for Fe₃O₄/FeN/N co-doped porous carbon aerogels from sodium carboxymethyl cellulose, tea polyphenols and polypyrrole. • Tea polyphenol−Fe 3+ coordination mitigates pyrolysis-induced framework shrinkage and enables uniform polypyrrole dispersion. • The CTP2-700 aerogel exhibits a minimum reflection loss of −58.4 dB (3.1 mm) and effective bandwidth of 5.3 GHz at 2.1 mm (20 wt% loading). • RCS simulations demonstrate good radar stealth; this work guides the design of lightweight biomass carbon-based electromagnetic absorbers. In recent years, the fabrication of lightweight porous carbon aerogels from biomass precursors has attracted considerable attention in the field of electromagnetic wave absorption. Herein, novel Fe 3 O 4 /FeN/N porous carbon aerogels were successfully synthesized using sodium carboxymethyl cellulose as the carbon source, with metal-phenolic networks constructed through the coordination of tea polyphenols and Fe 3+ . These networks not only enable homogeneous dispersion of polypyrrole but also mitigate the shrinkage of carbon frameworks during high-temperature pyrolysis, thereby maintaining the structural integrity of the aerogel products. The as-prepared carbon aerogels possess a hierarchical porous structure and well-developed conductive networks. Electromagnetic parameter tests revealed that the materials achieved a minimum reflection loss of −58.4 dB at a matching thickness of 3.1 mm, together with a broad effective absorption bandwidth of 5.3 GHz at a thickness of 2.1 mm. This work offers an innovative strategy for the green and efficient utilization of cellulose-based materials and demonstrates their potential for developing lightweight, high-performance electromagnetic wave absorbers.