Oxygen vacancy‐rich ZnO nanorods‐based MEMS sensors for swift trace ethanol recognition

Ethanol vapor plays a significant role in the aspects of human health and industrial production, thus necessitating a swift, sensitive, and low-power ethanol detection in the field of future gas sensors. In this work, we prepared microelectro-mechanical system ethanol sensors based on ZnO nanorods (NRs) and nanoparticles (NPs) for trace ethanol detection. Both ZnO samples were synthesized by a facile hydrothermal method. The comparison results exhibited that ZnO NRs based sensors prevailed over NPs-based counterparts in terms of sensitivity, optimal operation temperature, and reaction speeds. Briefly, that ZnO NRs-based sensors presented a large response (11.5 toward 5 ppm), fast response/recovery times (5 s/5 s), ultralow detection limit (400 ppb), and tiny power consumption (30 mW) at 245 degrees C, surpassing most of recently reported ethanol sensors and commercial products based metal oxides. The abundant oxygen vacancies, large specific surface area, and porous structure were primarily responsible for the excellent sensor performance. This work also offers a facile and competitive approach to realize a sensitive and swift trace ethanol recognition with minimal power consumption, catering for the demanding requirements of future gas sensors in the fields of wearable devices and Internet of Things.