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 degrees C to 100 ppm H-2 gas. Thus, highly selective sensors to H-2 gas were exhibited.