Visible light-activated ethanol sensor based on flower-like N3-loaded ZnO composites

Flower-like ZnO materials loaded by different amount of N3 dye were successfully synthesized via a facile one-step hydrothermal method. Several characterization techniques were applied to analyze the compositional, structural and morphological information of the products, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis spectrophotometer (UV-vis). Ethanol sensing properties of sensors were tested for the N3-loaded ZnO composites under various light illumination conditions. Unusually, the sensor based on 0.10 wt. % N3-loaded ZnO exhibits the higher response, lower detect limit, shorter response time and more outstanding selectivity under green light illumination in comparison to those of sensors loaded with other N3 concentration as well as sensors illustrated by UV light or in dark condition. This study demonstrates that dye loading is an efficient and promising route in the development of high-performance gas sensors based on wide-band gap semiconductors with visible light irradiation.