Highly selective H2 gas sensors based on ZnO-modified SnO2 nanorod arrays

In this work, uniform SnO₂ nanorod arrays have been grown by plasma-enhanced chemical vapor deposition (PECVD). The SnO₂ nanorods are about 5 nm at the tip, 20 nm in the bottom and 300 nm in length. The surface of the nanorods was modified by ZnO nanoclusters deposited by sputtering and by spin coating. The effects of ZnO surface modification on sensing properties of SnO₂ nanorod arrays were investigated. The SnO₂ nanorod array sensor modified with ZnO deposited by spin coating showed normal donor-like sensing response to CO gas, while it showed inverse acceptor-like sensing response up to 18.8 at 350 °C to 100 ppm H₂ gas. Thus, highly selective sensors to H₂ gas were exhibited.