Synergistic Effect of Pt-Loading and Mesoporous SnO₂ Layer-Coating on the Gas Sensing Properties of SnO₂ Thick Film Sensors

Abstract

Simultaneous surface modifications of SnO₂ powder with Pt-loading and mesoporous SnO₂ (m-SnO₂) layer-coating have been conducted. The sensors fabricated with the powders prepared with the Pt-loading and subsequent modification with the m-SnO₂ layer showed higher H₂ response than the sensors fabricated with the reverse procedure sequence. Similar synergistic effects in sensing properties to CH₄ and C₂H₅OH were also observed at higher operating temperatures. However, such a synergistic effect was not observed when CO was employed as a sample gas. Thus, strict control of mesoporous structure and loading state of Pt microparticles on the surface of SnO₂ powder was found to be effective technique, which improves the gas-response properties of SnO₂-based sensors.