Superior triethylamine detection at room temperature by {-112} faceted WO3 gas sensor

Effective detection of triethylamine (TEA) is important for the human health and environment, while challenging. In this study, a novel hierarchical flower-like WO3 nanomaterial was synthesized using a microwave-assisted gas-liquid interface method. The morphology and exposed facets of WO3 nanomaterials can be manipulated through the control of the volume ratio between the water and ethylene glycol (EG) during the synthesis. Our results demonstrate that the samples prepared with water/EG ratio of 8:32 are mainly exposed {-112} facets, which have the best gas sensing response of 180.7 to 100 ppm TEA at room temperature (RT). Its superior gas sensing performance and stability are also evidenced by the short recovery speed of 72 s to 100 ppm TEA at RT. More importantly, our experiments revealed an excellent selectivity in terms to other volatile organic compounds and further confirmed by the first-principles theoretical results. The outcomes of this study suggest that the surface engineering technique is a promising approach to improve the gas sensing performance of metal oxides gas sensor and show great potential for TEA practical detection and monitoring.