Pulsed laser deposited platinum and gold nanoparticles as catalysts for enhancing the CO sensitivity of nanostructured SnO2 sensors

We report on the influence of Pt and Au catalyst nanoparticles on the sensitivity towards CO of nanostructured SnO2-based sensors. The Pt and Au nanoparticles presenting various nanostructural characteristics were deposited on the top of the SnO2 sensing films by means of pulsed laser deposition (PLD). It is shown, for the first time, that Au nanoparticles can be as efficient as Pt nanoparticles for enhancing the sensing performance towards CO. While the catalytic activity of Pt nanoparticles is shown to present a sharp size effect (with a maximum peaking around 2 nm), the Au nanoparticles are found to exhibit a rather high reactivity over a wider range of particles size ranging from similar to 9 to 30 nm.