Ozone-assisted Cataluminescence Sensor Based on Morphology- Controlled TiO2 @Mg-MOF-74 Composite for Rapid Detection of N- hexane

As a volatile organic compound (VOCs) in air, N-hexane can cause damage to the nervous system. Therefor, it is essential to monitor the levels of n-hexane in air for human health. In this work, four different morphology TiO ₂ were successfully synthesized and the morphological dependence of the catalytic performance was investigated. TiO ₂ nanotubes showed the best catalytic performance for CTL reaction of n-hexane because of high specific surface area and ordered arrangement. To further enhance catalytic activity, TiO ₂ nanotubes@Mg-MOF-74 composite was synthesized,which was used to construct CTL sensor for detecting N-hexane rapidly, the introduction of Mg-MOF-74 improved the adsorptivity and selectivity. Then, a CTL sensor was construct based on TiO ₂ nanotubes@MOF-74 for the rapid detection of N-hexane, under the optimal conditions, there was a good linear relationship between CTL signal intensity and concentration of n-hexane in the linear range of 0.2–200.0 mg/L, and the detection limit (LOD, S/N  = 3) was 0.08 mg/L. The RSD values of the results for 11 consecutive measurements by one same sensor and 7 different sensors on the same day were 2.80% (n = 11) and 3.50% (n = 7), showing good repeatability and reproducibility. At last, the sensor was used to detect n-hexane in air samples from different workplaces, with recoveries ranging from 90.2–106.7%, showed good accuracy. Thus, the established CTL sensor could be used for the rapid detection of n-hexane content in the air, avoid damage to the body caused by excessive inhalation.