Controllable fabrication of hierarchical Bubble-like Co3O4 tubes with enhanced trimethylamine sensing performance

To facilitate the effective monitoring of human health and environmental quality, it is essential to develop high-quality gas sensors for trimethylamine (TEA) with stable sensing sensitivity and low resistance fluctuations in a wide range of humid atmospheres. To this end, a novel Bubble-like Co3O4 tube was fabricated through a ZIF-67 intermediate-assisted thermal decomposition strategy, and its surface morphology and nanostructure were comprehensively investigated. Furthermore, a systematic comparison of the gas sensing properties between Rod-like Co3O4 and Bubble-like Co3O4 was also conducted. The results demonstrated that the introduction of ZIF-67 intermediate not only decreased the baseline resistance of the Bubble-like Co3O4 sensor but also enhanced its gas-sensing performance. Specifically, the response value of the sensor fabricated using Bubble-like Co3O4 for detecting 100 ppm TEA at 180 °C was around ten times higher than that of the Rod-like Co3O4 sensor, while achieving a low detection limit of 55 ppb. Furthermore, the gas sensor exhibited excellent selectivity and anti-humidity stability, with negligible variation in response value even after 30 days, retaining approximately 98 % of the initial value. This remarkable sensing-performance can be attributed to several factors, including the large specific surface area, abundant oxygen vacancies, and efficient Co3+/Co2+ catalyzing. Overall, this work sheds new light on the rational design of high-performance TEA sensing materials for practical applications.