Quick Sensing Response of CuO Nanograins for Ethanol Vapour Detection: DFT Analysis of Surface Adsorption Traits

A copper oxide (CuO) sensing element was prepared through spray pyrolysis with optimized deposition conditions to obtain nanograins. Structural studies revealed the polycrystalline nature of the film, and the formation of pure CuO nanograins was confirmed through compositional analysis. Morphological studies confirmed the uniform distribution of the CuO nanograins and porosity of the material, which is critical for gas sensing applications. The prepared sensing element was exposed to various vapours. At 350°C, the prepared CuO nanograins exhibited better response to ethanol vapour. For 100 ppm of ethanol, a response time of 24 s and a recovery time of 35 s were noted. The change in the electrical characteristics of the CuO surface before and after contact with the ethanol molecule was investigated using density functional theory (DFT). All the results collectively indicate that the CuO sensing element can be used for ethanol sensing applications.