Biomimetic tourmaline/MXene lignocellulose nanofibers aerogel by directional-casting for efficiency fire-resistant, alarm and electromagnetic shielding

The rapid advancement of communication technology has led to issues of electromagnetic radiation, while the use of high-power electronic devices introduces potential fire hazards, threatening lives and property. Integrating flame retardancy, fire alarm functionality, and efficient electromagnetic interference (EMI) shielding into a single lightweight material remains a significant challenge. Here, we propose a biomimetic flame-retardant tourmaline/MXene lignocellulose hybrid aerogel (TMLA-D) with vertical channels using the liquid nitrogen directional freeze-casting method, which possesses both a heat-sensitive fire alarm response function and electromagnetic shielding capability. Compared to lignocellulose aerogel, the heat release rate and total heat release of TMLA-D are reduced by 48.42% and 23.28%, respectively. The limiting oxygen index is significantly enhanced by 47.69%. Upon flame exposure, its heat-sensitive response rapidly generates a potential difference exceeding 100 mV, actively triggering an alarm and extending a bulb’s operation time by 220% in a demonstration. Furthermore, the conductive network formed by MXene provides an electrical conductivity of 19.5 S m⁻¹ , resulting in an efficient electromagnetic interference (EMI) shielding effectiveness of 22 dB. The vertically aligned structure enhances EMI shielding effectiveness by establishing a continuous reflection-absorption pathway for electromagnetic waves. These properties indicate that the TMLA-D has excellent flame retardant, fire warning and electromagnetic shielding capabilities, thus offering a feasible solution for fire alarm systems. Synopsis This aerogel offers sustainable advantages through its biomass-derived lignocellulose base and multifunctional design that reduces material consumption.