Enhanced sensing performance of TiO₂/Ag₂V₄O₁₁ nanoheterostructures to ethanol gas

High performance sensor for gas species detection is a significant task not only for fundamental sciences but also for industries. In this study, a new type of ethanol gas sensor based on one-dimensional TiO₂/Ag₂V₄O₁₁ nanoheterostructures (NHSs) is reported. The sensitivity of the NHSs to ethanol is much higher than those of pure TiO₂ and Ag₂V₄O₁₁. By regulating the content of TiO₂ and Ag₂V₄O₁₁, it is found that TiO₂/Ag₂V₄O₁₁ NHSs with T/A (TiO₂/Ag₂V₄O₁₁) molar ratio of 2:1 exhibit excellent sensing performances to ethanol. The sensitivity at 300 °C to 100 ppm ethanol is 25.6, about 6 times and 3 times higher than TiO₂ and Ag₂V₄O₁₁, respectively, and the sensor also possesses good selectivity to ethanol gas. Specifically, the NHSs exhibit efficient sensitivity (4.2–100 ppm ethanol gas) and excellent stability at room temperature. High-depth mechanism study reveals that besides the contribution of the fast electron transfer properties of the Ag₂V₄O₁₁, the formation of nanoheterojunctions and the rich surface interfaces rooting from the hybridization of nanoparticles (NPs) and nanowires (NWs) can significantly enhance the sensing performance of the NHSs.