Enhanced Acetic Anhydride Detection Based on ZnO/ La2O3 Nanoparticles with High Selectivity and Sensitivity

Acetic anhydride is a crucial chemical composition for heroin synthesis and is also a hazardous volatile organic compound. Hence, the development of a reliable and sensitive chemical sensor for its detection is essential. In this study, ZnO/La ₂ O ₃ nanoparticles were successfully synthesized via a simple one-step hydrothermal process to detect acetic anhydride. The surface morphology, composition, and microstructure of particles were thoroughly analyzed. The 0.2 at% La-ZnO based gas sensor exhibits a maximum of 422 toward 100 ppm acetic anhydride at the optimal operating temperature of 300°C. The synergistic catalysis between ZnO and La ₂ O ₃ heterojunction solves the problem of low sensitivity of pure ZnO to acetic anhydride. The unique selectivity and high sensitivity of sensors to acetic anhydride are associated with the Lewis acids-bases interaction because of the enhanced Lewis base sites on the surface of sensing materials. Significantly, the gas-sensitive mechanism is elaborated, including the effect of heterojunction and oxygen vacancies, and the catalysis of La ₂ O ₃ . The most important thing is that the rapid detection of acetic anhydride has been realized, which is significant in curbing the spread of drugs.