UV-enhanced gas sensing properties of ZnTiO3

초록

ZnTiO3 nanowires were synthesized by using a thermal evaporation technique. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction revealed that the nanowires were single crystals and 40-120 nm in diameter and up to a few hundreds of micrometers in length. The sensing properties of multiple networked ZnTiO3 nanowire sensors toward NO2 gas at room temperature under UV irradiation were examined. The ZnTiO3 nanowire gas sensors showed a remarkably enhanced response to NO2 gas at room temperature under ultraviolet (UV) light illumination. The response of the ZnTiO3 nanowires to NO2 gas at room temperature increased from ~81 to ~724% with increasing the UV light illumination intensity from 0 to 1.2 mW/cm2. The significant improvement in the response of the ZnTiO3 nanowires to NO2 gas by UV irradiation is attributed to the increased change in resistance due to the increase in the number of electrons participating in the reactions with NO2 molecules by photo-generation of electron-hole pairs.