Fabrication and H2-Sensing Properties of SnO2 Nanosheet Gas Sensors

Abstract

Vertically formed and well-defined SnO2 nanosheets are easy to fabricate, involving only a single process that is performed under moderate conditions. In this study, two different sizes of a SnO2 nanosheet were concurrently formed on a Pt interdigitated electrode chip, with interconnections between the two. As the SnO2 nanosheets were grown over time, the interconnections became stronger. The ability of the fabricated SnO2 nanosheets to sense H2 gas was evaluated in terms of the variation in their resistance. The resistance of a SnO2 nanosheet decreased with the introduction of H2 gas and returned to its initial level after the H2 gas was replaced with air. Also, the response-recovery behaviors were improved as a result of the growth of the SnO2 nanosheets owing to the presence of many reaction sites and strong interconnections, which may provide multipassages for the electron transfer channel, leading to the acceleration of the reaction between the H2 gas and SnO2 nanosheets.