Self-Templated Hierarchically Porous Graphitic Aerogels for Emi Shielding

As electronic systems become increasingly integrated into daily life, the demand for lightweight, effective, and environmentally sustainable materials for electromagnetic interference (EMI) shielding continues to grow. In this study, we investigate the EMI shielding performance of hierarchically porous graphitic aerogels (HGAs) synthesized from albumen protein through controlled pyrolysis. These single-component, bio-derived aerogels differ from conventional carbon aerogels by combining ultralow density, hierarchical porosity, and tunable electrical conductivity without templating, chemical activation, surface functionalization, or multistep processing. By varying the carbonization temperature, heating rate, and sample thickness, we demonstrate direct control over the aerogel's microstructure, density, and electrical properties, and consequently, the EMI shielding behavior. The HGA exhibits an outstanding specific shielding effectiveness of over 16 200 dB cm² g^{- 1}, outperforming previously reported single-component carbon-based aerogels synthesized through simple pyrolysis by more than an order of magnitude. Furthermore, we show that processing conditions can be used to deliberately control the dominant attenuation mechanism, enabling a shift from reflection-dominated to absorption-dominated shielding behavior, with the latter being particularly promising for mitigating secondary electromagnetic pollution. These findings establish protein-derived, single-component HGAs as a simple, tunable, and high-performance platform for EMI shielding, with broad implications for aerospace, electronics, and future wireless communication technologies.