Nanocrystalline Metal Oxides for Methane Sensors: Role of Noble Metals
Figure 1
The schematic of hydrogen or methane sensing using catalytic metal on metal oxide film. (a) A typical noble metal/metal oxide Schottky junction. (b) When exposed to hydrogen or methane a voltage shift occurs in the capacitance—voltage characteristics. (c) Diffusion of hydrogen through the noble metal and formation of dipole layer across the noble metal/ metal oxide junction.