PVA/Ti3C2Tx/CoFe2O4 nanocomposite hydrogel for TENG-powered and flexible gas sensor: towards highly selective room temperature triethylamine gas detection with fast response and recovery

The development of triboelectric nanogenerator (TENG)-powered gas sensors capable of actively harvesting environmental energy has become critically important in today's energy-conscious world. This study presents a triethylamine (TEA) gas sensor based on a PVA/MXene/CoFe 2 O 4 nanocomposite hydrogel TENG, utilizing heterointerface-rich MXene/CoFe 2 O 4 nanomaterials combined with polyvinyl alcohol (PVA) polymer matrix. Systematic characterization via XRD, XPS, SEM, and TEM elucidated the composite's elemental composition and microstructure. The PTMC-7 TENG-powered sensor demonstrated exceptional electrical output, generating 170 V open-circuit voltage under 7 N contact force at 1 Hz frequency - sufficient to power 30 LEDs through rectifier-integrated circuits. Its silicone encapsulation enabled finger-joint mounted micro-motion detection. The sensor exhibited 105.11 % response to 100 ppm TEA at room temperature with fast response/recovery (31 s/23 s) and outstanding stability (<3.2 % degradation over 30 days). By converting TENG output modulation into gas concentration readings, this design achieves battery-free TEA detection while synergistically integrating energy harvesting and sensing functionalities, establishing a novel paradigm for flexible sensor development.