Integrated Temperature–NH₃ Multiplex Sensing Fibers Enabled by Programmable Assembly of MXene@MoS₂ Heterojunction and p/n-Type Thermoelectric Core for Firefighting Clothing

Abstract

Firefighting clothing provides essential safeguards for firefighters while engaging in fire suppression and life rescue operations. However, the inability to actively detect hazardous gas and self-thermal degradation of conventional firefighting clothing induce critical safety threats to firefighters. Herein, we design a dual-mode perceptual sensor via programmable assembly of single-walled carbon nanotubes (SWCNTs) and Ti₃C₂T_x MXene@MoS₂ nanocomposite in dual-mode triaxial structural aerogel fiber (DM-TSF) for both selective NH₃ and temperature monitoring. The DM-TSF is prepared through triaxial wet spinning, with an alternating p/n-type thermoelectric (TE) core, a signal decoupling aramid nanofibers layer, and an NH₃ sensing outer sheath. The TE core is composed of alternately interconnected p-type/SWCNT and n-type SWCNT/Polyethyleneimine, which exhibits high TE efficiency (8.44 μV K⁻¹ for p-segment, 7.44 μV K⁻¹ for n-segment) and wide-range (10–500 °C) temperature monitoring in DM-TSF. Furthermore, the abundant adsorption sites and high-density Schottky heterojunctions of the Ti₃C₂T_x MXene@MoS₂ nanocomposite in the outer sheath enabled DM-TSF to exhibit an outstanding sensitivity (3.14% ppm⁻¹@20 ppm) and high selectivity for NH₃. A portable wireless system based on DM-TSF was further developed and integrated into firefighting clothing for temperature and NH₃ monitoring, triggering alarms within 2 s and 28 s, respectively. This work sheds new light on the fabrication of intelligent multiplex hazard detection fibers that can respond to multi-hazard elements, thereby enhancing firefighters’ safety in complex fire scenarios.

Graphical Abstract

Keywords

Coaxial wet spinning / Temperature–NH₃ sensing fiber / MXene nanosheets / MXene@MoS₂ heterojunctions / Multiplex hazard detection

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Funding

Guiding Project of Scientific Research Plan of Education Department of Hubei Province

Wuhan Textile University School Fund (B)(k24016)

RIGHTS & PERMISSIONS

Donghua University, Shanghai, China