Preparation of silver nanoparticles modified SnO2 humidity sensor for tobacco storage environment detection

Abstract

In this paper, silver nanoparticles (AgNPs) modified SnO2 (Ag/SnO2) nanocomposite with excellent humidity performance was prepared by hydrothermal method. Experimental results demonstrate that AgNPs enhance the performance of the SnO2 humidity sensor, which is primarily attributed to increase the oxygen vacancies on the surface of the SnO2 through the incorporation of AgNPs. Density functional theory (DFT) demonstrated that more oxygen vacancies can enhance the chemical and physical adsorption energy of water molecules by SnO2, and decompose more water molecules into conductive H+ ions: simultaneously, the response/recovery times and hysteresis error of SnO2 are reduced. Compared to the SnO2 humidity sensor, Ag/SnO2 exhibits low humidity hysteresis (2.7%), relatively short response/recovery time (5/8 s) and high sensitivity (24292.3). Furthermore, the Ag/SnO2 humidity sensor employed in this study has successfully demonstrated its efficacy in detecting humidity levels within tobacco storage environments, which expands the potential applications of humidity sensors.