Ozone-assisted cataluminescence sensor based on morphology-controlled TiO2@Mg-MOF-74 composite for rapid detection of N-hexane

Four different morphologies of TiO 2 were successfully synthesized and the morphological dependence of the catalytic performance was investigated for monitoring of n -hexane. TiO 2 nanotubes showed the best catalytic performance for the cataluminescence (CTL) reaction of n -hexane because of their high specific surface area and ordered arrangement. To further enhance catalytic activity, a TiO 2 nanotube@Mg-MOF-74 composite was synthesized, which was used to construct a CTL sensor for rapid detection of n -hexane rapidly; the introduction of Mg-MOF-74 improved the adsorption capacity and selectivity. A CTL sensor was constructed based on TiO 2 nanotube@Mg-MOF-74 for the rapid detection of n -hexane, Under the optimal conditions there was a good linear relationship between CTL signal intensity and the concentration of n -hexane in the range 0.20–200.0 mg/L. The detection limit (LOD, S/N  = 3) was 0.08 mg/L. The RSD values for 11 consecutive measurements using the same sensor and 7 different sensors were 2.8% ( n  = 11) and 3.5% ( n  = 7), respectively, demonstrating good repeatability and reproducibility. Finally, the sensor was used to detect n -hexane in air samples from different workplaces, with recoveries ranging from 90.2 to 106.4%, showing good accuracy. Thus, the developed CTL sensor could be used for rapid detection of n -hexane in air, avoiding damage to health caused by excessive inhalation. Graphical abstract