ZnO:Cd nanorods hydrogen sensor with low operating temperature

In this paper, the properties of hydrogen (H2) sensor based on Cd-doped zinc oxide (ZnO:Cd) nanorods are investigated. The nanorods are synthesized using hydrothermal method and sensors are fabricated by spinning nanorods on the glass substrate. All samples show the hexagonal phase of wurtzite, and their XRD diffraction peaks shift slightly to lower 2θ angle when the concentration of Cd increase. The cadmium dopant plays a vital role in fine tuning the structure of crystal and the size of rods, and it also enhances the stability of ZnO. Via Cd-doping, the performance of hydrogen sensors based on ZnO nanorods improves significantly. Among all sensors doped with various Cd concentration, the 2 at% Cd-doped sensor performs best, since it is able to detect 500 ppm hydrogen at relatively lower operating temperatures ranging from 50 °C to 100 °C with faster response and shorter recovery time.