A self-powered β-Ni(OH)2/MXene based ethanol sensor driven by an enhanced triboelectric nanogenerator based on β-Ni(OH)2@PVDF at room temperature

In the era of the Internet of Things (IoT), the promotion of self-powered ethanol sensors is essential in many fields such as agriculture and chemical industry. This work presented a β-Ni(OH)2/MXene gas-sensing composite and a β-Ni(OH)2@PVDF triboelectric nanogenerator (NP-TENG). An NP-TENG-driven ethanol gas sensor (NNES) was constructed by directly connecting the NP-TENG in series with interdigital electrodes coated with β-Ni(OH)2/MXene sensitive composite. In a room temperature and high-humidity environment, the NP-TENG produces a peak-to-peak voltage of 427.95 V and output power density of 482.9 mW/m2, which exhibits an abundant self-powered ability to operate not only microelectronic devices, such as LEDs and thermo-hygrometer sensor, but also to detect body movements, such as finger touch, elbow bend, etc. The NNES demonstrates a high response (∼6.67) and rapid response/recovery time (15 s/4 s) towards 100 ppm ethanol vapor at a relative humidity of 87 % and a room temperature of 26 °C. Moreover, the sensor has excellent repeatability, selectivity, and long-term stability. This work broadens TENG's application area for self-powered gas sensors as well as responds to the requirements for low-powered, miniaturized, and maintainable sensors for IoT technologies in agriculture and industry.