H2 sensors based on WO3 thin films activated by platinum nanoparticles synthesized by electroless process

Platinum (Pt) nanoparticles were successfully synthesized on tungsten oxide (WO3) thin films by electroless process without any further post-treatment. The prepared Pt nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and field-emission scanning electron microscopy. Gas sensors based on the Pt–WO3 films were found to provide repeatable and significant responses to ppm-level H2. The size of Pt nanoparticles increases with the deposition time and has improved the sensing characteristics of the sensors. The work in this paper paves a facile way to the fabrication of Pt nanoparticles on metal oxide surface at a low temperature (68 °C).