MXene/Co3O4 composite based formaldehyde sensor driven by ZnO/MXene nanowire arrays piezoelectric nanogenerator

Formaldehyde is widespread in daily life and industrial production, and the detection of formaldehyde is an important measure related to human health. Currently, self-powered high-performance gas sensors have aroused great interests. In this work, MXene/Co3O4 composite-based formaldehyde (HCHO) sensor working at room temperature (RT) driven by ZnO/MXene nanowire (NW) arrays piezoelectric nanogenerator (PENG) was reported. A series of characterizations were performed to verify the synthesis of the sensing materials. With HCHO concentration increasing from 0.01 ppm to 10 ppm, the MXene/Co3O4 composite sensor showed obvious response. The piezoelectric output voltage based on ZnO/MXene NW arrays showed great self-powered ability to drive the MXene/Co3O4 composite sensor. The humidity influence and the flexibility of the gas sensor were investigated for potential application. In addition, the flexible PENG can be used to collect human motion energy as wearable devices. The possible gas sensing mechanism was attributed to the synergistic interfacial interactions between MXene and Co3O4.