Multifunctional poly(vinyl alcohol)/Ag nanofibers-based triboelectric nanogenerator for self-powered MXene/tungsten oxide nanohybrid NO2 gas sensor

Triboelectric nanogenerators (TENGs) have broad application prospects in flexible electronics and self-powered sensing devices. In this paper, a poly(vinyl alcohol)/silver (PVA/Ag) nanofibers-based TENG was developed for human respiration, movement and harmful gas monitoring. The peak-to-peak value of open-circuit voltage and powered density from the wind-driven PVA/Ag-based TENG can reach up to 530 V and 359 mW/m2, respectively. Constant voltage output can be achieved at a large range of wind speeds (2.5–8 m/s) and humdity levels (30–65% RH) by integrating a voltage regulator module with the wind-driven TENG, which provides a feasible solution for the wind-driven TENG as a stable voltage source under different wind strength. The self-powered Ti3C2Tx MXene/WO3 sensor driven by TENG has an excellent response (ΔUs/Usa = 510% @ 50 ppm) for NO2 gas at room temperature, which is 15 times larger than that of the resistive MXene/WO3 sensor. A multifunctional self-powered detection system was developed by integrating four TENGs with a gas sensor for detection of wind direction and wind-borne NO2, which can be used to trace the source of harmful gases. The wind-driven self-powered sensor system provides a sustainable and maintenance-free detection platform, which has great application potential in the field of environmental monitoring.