High-performance ethanol sensor based on Ag/In2O3 heterojunction with exceptional sensitivity and selectivity

Detecting ethanol is critically important due to its widespread industrial applications and potential safety hazards, posing significant risks to both industrial production and human health. However, the development of ethanol sensors with high sensitivity and selectivity remains a substantial challenge. In this study, we demonstrate a highly sensitive and selective ethanol sensor based on rationally-designed heterojunctions, fabricated by decorating In2O3 nanotubes with Ag nanoparticles (NPs) through solvothermal and coprecipitation methods. The obtained Ag/In2O3 sensor exhibits exceptional ethanol sensing performance (S = 110.5 to 100 ppm), which exhibits an approximately 11-fold enhancement compared to that of pristine In2O3, and surpasses those of most ethanol sensors ever reported. Such improvement is mainly attributed to the synergistic effects of Schottky junction formation, electronic sensitization, and chemical catalysis, which collectively enhance electron transfer efficiency and surface reaction kinetics. Moreover, the as-constructed sensor demonstrates rapid response/recovery characteristics (50/70 s), excellent selectivity against interfering gases, and remarkable long-term stability, representing its promise toward practical applications.