The room-temperature sensing performance of ZnO nanorods for 2-methoxyethanol solvent

Quasi-vertically aligned zinc oxide nanorod (ZnO NR) arrays were synthesized via hydrothermal processing on glass substrates coated with a conductive layer of aluminium-doped zinc oxide (AZO). Different characterization techniques were used to study the phase structures, surface morphology and elemental composition of the prepared nanorods, including X-ray diffraction (XRD), field emission scanning microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). The sensing behaviour of the ZnO NR arrays has been demonstrated toward different concentrations of 2-methoxyethanol solvent, a highly toxic organic compound. The sensitivity of the prepared sensor is 24 nA/(ppm cm−2) and 60 nA/(ppm cm−2) at applied voltages of 5 V and 10 V, respectively. Its limit of detection (LoD) is 190 ± 5 ppm independently of the applied voltage. The mechanism of the sensing behaviour was explained based on the charge-transfer mechanisms.