The effect of Pd on the H2 and VOC sensing properties of TiO2 nanorods

This work presents highly sensitive TiO2 nanorods modified with palladium to investigate the sensing properties of H2 and volatile organic compound (VOC) gases. TiO2 nanorods were synthesized in a mixed solution containing 1 ml of titanium n-butoxide (TnBT) by the hydrothermal method. Pd on the surface of the TiO2 nanorods was decorated by heat treatment. The samples were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. The electrical properties of the TiO2 and Pd loaded TiO2 nanorods were investigated under a dry air flow at a temperature range from 30 °C to 200 °C. The H2 sensing properties of the TiO2 nanorods decorated with Pd were investigated in the concentration range of 500-2000 ppm at 200 °C. Moreover, the effect of Pd on the VOC gas sensing properties of the TiO2 nanorods was examined at 200 °C. The results revealed that the nanorods modified with palladium exhibited excellent sensing performance to H2 at 30 °C, and also had the appropriate sensor behavior at 200 °C with clear response-recovery, good stability, and reproducibility. The maximum VOC response was obtained for ethanol.