Fabrication of H2 Gas Sensor Based on ZnO Nanarod Arrays by a Sonochemical Method

We report a simple method for fabricating ZnO gas sensors via a sonochemical route and their H2 gas sensing properties. Vertically aligned ZnO nanorod arrays as a sensing material were synthesized on a Pt-electrode patterned alumina substrate under ambient conditions. The advantage of the proposed method is a high speed of processing. The gas sensor based on ZnO nanorod arrays with large specific surface area showed a high response to H2 and a detection limit of 70 ppm at 250 oC. Also, their response and recovery time were relatively short and a complete regeneration was observed. A mechanism for sensing H2 gas on the surface of ZnO nanorods is proposed. Key Words: Sonochemistry, ZnO gas sensors, Nanorod array