Study on the sensitivity of transition metal-modified WO3 materials toward triethylamine and H2S gases in food safety by density functional theory

Abstract

The corrupt triethylamine gas and H₂S gas in food safety pose a threat to food and human health. The development of efficient gas sensing materials can sensitively monitor these gases to ensure the safe development of the food industry. In this study, the sensitivity mechanism of transition metal Me (Me = Co, Fe, Mn, Ni) modified WO₃-based sensors was systematically investigated based on density functional theory (DFT). By calculating the adsorption energy, electronic structure and charge transfer characteristics of gas molecules on the modified WO₃ surface, it is found that the introduction of transition metal Me significantly enhances the chemical adsorption capacity of WO₃ for triethylamine and H₂S, and has higher charge transfer ability for H₂S and TEA. The analysis of electron density of states shows that the synergistic effect of Me metal and WO₃ interface reduces the valence band of WO₃–002 composite material and transforms into conductor. There are free electrons near Me atom, forming metal‑oxygen bonds with surrounding O atoms, which is more conducive to the migration of electrons. This change is more conducive to the adsorption of gas molecules and improves the selectivity of gas recognition. The transition metal modification strategy can effectively optimize the performance of WO₃-based sensors. This study provides a new idea for the design of food safety rapid detection devices.