Synergy Effect of Noble Metal-loading and Surface Modification with Mesoporous SnO2 on the Gas-sensing Properties of SnO_2

摘要

Simultaneous surface modification of SnO_2 powder with a mesoporous SnO_2 (m-SnO_2) layer and noble metal-loading has been conducted. The sensors fabricated with the powders prepared with Pt-loading and subsequent modification with the m-SnO2 layer showed higher H_2 response than the sensors fabricated with the reverse procedure sequence. Similar synergistic effects in sensing properties to CH_4 and C_2H_5OH were also observed at higher operating temperatures. However, such a synergy effect was not observed when CO was employed as a sample gas. Thus, strict control of mesoporous structure and loading state of catalyst microparticles on the surface of SnO_2 was found to be effective technique, which improved the gas-response properties of SnO2-based sensors.