Sensing properties of hydrogen sensors based on tungsten oxide films activated by platinum nanoparticles prepared by electroless deposition

The characteristics of platinum (Pt) nanoparticles deposited by electroless process on the tungsten oxide (WO3) films and the sensing characteristic of platinum nanoparticles activated WO3 films (Pt-WO3) to hydrogen are addressed in this paper. The WO3 films were grown on Al2O3 substrate by radio-frequency sputtering. An acidic bath having chloroplatinic acid as source of platinum was used to prepare Pt nanoparticles. The films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and filed-emission scanning electron spectroscopy. The sensing performance of the Pt-WO3 films to 25-200 ppm H2 was demonstrated.