A novel sensor for fast detection of triethylamine based on rutile TiO2 nanorod arrays

A TiO2 nanoparticle (TP) film is employed as a seed layer for the hydrothermal growth of single crystalline rutile TiO2 nanorod arrays on the substrate. The TP films were prepared by dip coating method from the TiO2 sols. The TiO2 nanorods are smooth with the average diameter of ∼65 nm and the length of ∼1 μm. The nanorods consist of parallel tiny nanotips about 3–5 nm in diameter on the top surface of the stem nanorod. Morphological evolutions versus reaction time were explored in detail through a series of SEM and XRD characterizations. The results indicated that the size of the rods increased with the reaction time increasing. A thin film sensor was formed from different sizes of single crystalline rutile TiO2 nanorod arrays growing on a ceramic tube in situ and exhibited an improved triethylamine sensing performance with a fast response of 2 s and a detection limit of 0.1 ppm. The experiment results show that the TiO2 nanorod arrays are a kind of promising material for detecting trace TEA.