Аңдатпа
The detection of volatile organic compounds (VOCs) released during spoilage is crucial for monitoring food quality and safety in storage and transportation. These VOCs serve as key indicators of microbial activity and chemical degradation, making them essential targets for gas-sensing applications. Various materials, including metal oxides and polymer-based composites, have been explored for their ability to detect spoilage-related VOCs due to their sensitivity and selectivity [1]. However, the efficiency of these sensors depends on factors such as surface properties, defect states, and adsorption mechanisms. This study employs Density Functional Theory (DFT) to systematically investigate the interaction of VOCs with sensing materials, focusing on the role of surface modifications and defects in enhancing sensor performance. Understanding these mechanisms will aid in the development of highly sensitive and selective sensors for real-time spoilage detection [2]. This study investigates the ZnO (100) surface for its ability to detect various toxic volatile organic compounds (VOCs) released during spoilage. The findings suggest that the ZnO (100) surface exhibits selectivity toward ethanol and acetone gases. Structural analysis of the ZnO (100) surface determined lattice constants of a = 3.263 Å and c = 5.235 Å , with a unit cell volume of 48.30 ų . The adsorption energy of ethanol on the ZnO surface was calculated as -94.45 eV , indicating a strong and favorable interaction. The ethanol molecule interacted with the surface via the hydroxyl group site, drawing +1.27e of charge from the surface. The ethanol gas exhibits a high adsorption energy on the surface, making its desorption more challenging. Consequently, elevated temperatures are required to facilitate gas desorption. To address this and lower the operating temperature of the gas sensor, we propose the development of a ZnO/CuO heterostructure. In this study, we employed the CuO(111) surface to examine gas adsorption behavior, where ethanol showed an adsorption energy of -1.75 eV on the heterostructure. The analysis of adsorption energy, bond length alterations, and structural parameters offers a comprehensive understanding of interaction dynamics at the molecular level, which is crucial for advancing sensor technology in monitoring air quality and detecting hazardous gases. Figure 1