Effect of noble metal functionalization and film thickness on sensing properties of sprayed TiO2 ultra-thin films

Abstract

In this paper, the effect of the thickness of nano-structured TiO2 thin films (12–40nm) and successive deposition of different noble metal nanoparticles on the performances of propanol vapor and H2 gas sensors was investigated. The obtained titania thin films were integrated into a device for UV, gas, and gas/vapor sensing studies at different operating temperatures. Qualitative analysis revealed that the sensor selectivity and its response could be altered by film thickness and type of noble metal nanoparticles. The results indicate that the sensor with 40nm TiO2 film has the highest response to H2 gas (˜ 650%). The fastest response time and the most rapid recovery however were achieved by the sensors made of 12nm sprayed TiO2 ultra-thin films, which also offered the highest selectivity to H2 gas.