Selective trimethylamine sensors based on Co3O4 modified WO3 spheres

Co3O4 modified WO3 microspheres with excellent trimethylamine (TMA) gas sensitive performance were prepared by a simple hydrothermal method using ZIF-67 as a template. The morphology, elemental composition, structure of the compounds, and gas-sensitive properties of the sensors based on them were researched by SEM, XRD, XPS as well as the gas-sensing analysis system. The prepared Co3O4 modified WO3 spheres exhibit significantly enhanced TMA gas sensitive properties, such as high response (198) to 100 ppm TMA, excellent selectivity, rapid response/recovery rate (11.7/2.1 s), good repeatability, long-term stability, and low detection limit (0.17 ppm) at 285 celcius. The sensing properties of the WO3/Co3O4 sensor may be due to the large surface area, significant resistance modulation effect of the p-n heterostructure, and catalytic effect of Co3O4. This work suggests that Co3O4 modified WO3 spheres may play an important role in the field of high-performance TMA sensors.