Hydrothermally grown oriented ZnO nanorod arrays for gas sensing applications

TLDR

C‑axis vertically aligned ZnO nanorod arrays were grown on a ZnO thin film via a simple hydrothermal method. The resulting nanorod arrays, 30–100 nm in diameter and several hundred nanometers long, enabled a gas sensor with high sensitivity to H₂ (20 ppm detection limit) up to 250 °C and strong responses to NH₃ and CO, indicating promise for cost‑effective, high‑performance sensing.

Abstract

C-axis vertically aligned ZnO nanorod arrays were synthesized on a ZnO thin film through a simple hydrothermal route. The nanorods have a diameter of 30–100 nm and a length of about several hundred nanometres. The gas sensor fabricated from ZnO nanorod arrays showed a high sensitivity to H2 from room temperature to a maximum sensitivity at 250 °C and a detection limit of 20 ppm. In addition, the ZnO gas sensor also exhibited excellent responses to NH3 and CO exposure. Our results demonstrate that the hydrothermally grown vertically aligned ZnO nanorod arrays are very promising for the fabrication of cost effective and high performance gas sensors.