Double-layer capsule of mesoporous ZnO@SnO2 for sensitive detection of triethylamine

Abstract

To overcome obstacles such as low response and poor selectivity of pure ZnO and SnO₂ gas sensors, the ZnO@SnO₂ sensor was synthesized by hydrothermal synthesis. The samples were characterized by XRD, XPS, SEM, HRTEM, N₂ adsorption–desorption and other techniques. The results show that ZnO@SnO₂ forms an n–n-type heterostructure and presents a double-layer capsule with a size of 0.5–4 μm. The results show that compared with pure ZnO and SnO₂, the ZnO@SnO₂ sensor exhibits a higher response (138.9) to 50 ppm triethylamine (TEA) at 152°C, which is 19.56 times that of the pure ZnO sensor and 21.7 times that of the SnO₂ sensor. It has a short response/recovery time (11/11 s), excellent selectivity and cycling stability. Compared with other volatile organic compounds or gases, it has higher selectivity for TEA detection.