Unveiling the role of oxygen vacancies: Micropore-rich Ovm-TiO2 nanocatalysts for enhanced cataluminescence detection of isobutyraldehyde

This study addresses the urgent demand for simple and sensitive online gas monitoring technologies in the field of environmental safety by developing a high-performance cataluminescence (CTL) sensor based on oxygen-vacancy-rich microporous titanium dioxide (Ovm-TiO 2 ) for detecting trace isobutyraldehyde (IBL). The Ovm-TiO 2 material, synthesized via a two-step heating process combined with a KBH 4 treatment, features abundant oxygen vacancy defects on its surface, which are pivotal to enhancing sensor performance. Density functional theory (DFT) calculations unravel the surface-mediated mechanism, the oxygen vacancies serve as active sites, drastically enhancing the chemical adsorption and activation of O 2 on the Ovm-TiO 2 surface, which is the key to boosting the cataluminescence efficiency. The developed sensor exhibits outstanding detection performance for IBL, with a wide linear range (0.0100–5.00 mg/L, R 2  = 0.9997), a low detection limit (3 μg/L), and achieved recovery rates of 87.6%–107% with good reproducibility (relative standard deviation, RSD: 5.3%–9.0%) in practical sample analysis. This work not only provides a viable online monitoring solution for IBL but also elucidates the CTL enhancement mechanism at the atomic level, offering important theoretical foundations and practical insights for designing highly sensitive gas sensors.