Mesoporous ZnO nanosheet as gas sensor for sensitive triethylamine detection

Controlled evolution of surface microstructure and phase boundary of ZnO nanoparticles for the multiple sensitization effects on triethylamine detection

In ZnO gas sensors, donor defects (such as zinc interstitials and oxygen vacancies) are considered active sites for the chemical adsorption and ionization of oxygen on the surface of ZnO, which can significantly enhance the sensor's response. However, the influence of the surface microstructure and phase boundaries of ZnO nanoparticles on the chemical adsorption and ionization of surface oxygen has rarely been explored. In this study, we developed a mixed-phase ZnO nanoparticle gas sensor with a rich phase boundary showing 198-50 ppm improvement in response to triethylamine at 340 °C. This is attributed to the generation of defects originating from lattice mismatch at the ZnO - zincite phase boundaries, which providing more active sites for adsorption of oxygen and triethylamine molecules. This work demonstrates a feasible method of combining surface microstructure regulation with pyrolysis strategies to develop ZnO sensors with significantly enhanced gas response performance.

Metal Oxide Semiconductor Sensors for Triethylamine Detection: Sensing Performance and Improvements

Triethylamine (TEA) is an organic compound that is commonly used in industries, but its volatile, inflammable, corrosive, and toxic nature leads to explosions and tissue damage. A sensitive, accurate, and in situ monitoring of TEA is of great significance to production safety and human health. Metal oxide semiconductors (MOSs) are widely used as gas sensors for volatile organic compounds due to their high bandgap and unique microstructure. This review aims to provide insights into the further development of MOSs by generalizing existing MOSs for TEA detection and measures to improve their sensing performance. This review starts by proposing the basic gas-sensing characteristics of the sensor and two typical TEA sensing mechanisms. Then, recent developments to improve the sensing performance of TEA sensors are summarized from different aspects, such as the optimization of material morphology, the incorporation of other materials (metal elements, conducting polymers, etc.), the development of new materials (graphene, TMDs, etc.), the application of advanced fabrication devices, and the introduction of external stimulation. Finally, this review concludes with prospects for using the aforementioned methods in the fabrication of high-performance TEA gas sensors, as well as highlighting the significance and research challenges in this emerging field.