Preparation and properties study of high performance Eu2Sn2O7–SnO2 composites humidity sensor

Abstract

In the work, a high-performance Eu2Sn2O7–SnO2 (ES-2) humidity sensors were prepared through a one-step hydrothermal method. Eu2Sn2O7 is a bimetallic material can increase the adsorption capacity to water molecules and promote electron transfer, thus improving the sensitivity of the sensor. The introduction of Eu2Sn2O7 promotes the increase of the content of oxygen vacancies in the ES-2 composite material, which promotes the accelerated decomposition of water molecules, and facilitates the formation of the chemisorbed layer to improve the sensitivity of the sensor and the response time. The increase in specific surface area of ES-2 provided more adsorption sites for H2O and also provided a good transport channel for water molecules to diffuse into the interior of the material. ES-2 humidity sensor exhibits high sensitivity (22,405 ± 363), small humidity hysteresis (1 ± 0.3 %), short response/recovery time (7/6 ± 0.5 s), good repeatability and stability (11%–95 % RH). This study not only promotes the development of SnO2-based humidity sensors, but provides new ideas for the preparation of high-performance humidity sensors.