Conduction-atomic force microscopy study of H2 sensing mechanism in Pd nanoparticles decorated TiO2 nanofilm

In situ conduction-AFM is used to observe room temperature hydrogen gas response mechanism of Pd nanoparticles decorated TiO2 nanofilm. The response mechanism is due to chemical and electronic sensitization of the nanofilm. The nanofilm with thickness ∼5 nm, in range of the wall thickness of a typical TiO2 nanotube, is prepared by atomic layer deposition. For the mechanism study and also for hydrogen sensor applications, this nanofilm with electrical conduction switching from the order of picoampere in air, to ∼0.30 μA in 1000 ppm H2 is an alternative to TiO2 nanotube/nanostructures.