Enhanced Gas Sensing Characteristics of Au-Loaded TiO2 Nanotube Sensors

The loading of noble metals was carried out to enhance the gas sensing characteristics of TiO2 nanotube-based sensors. Using a photochemical deposition method, Au nanoparticles were successfully deposited on TiO2 nanotubes prepared by a hydrothermal method in a highly-dispersed state. The sensor device using a porous film composed of the Au-loaded (0.5 wt%) TiO2 nanotubes exhibited improved sensor responses to 10-50 ppm toluene in air at 500 degrees C. The sensor response was about two times higher than that of a sensor using commercial TiO2 nanoparticles (degussa P-25). The results demonstrate that the Au loading is a very efficient method for improving the sensing characteristics of TiO2 nanotube-based sensors operative at high temperatures.