Abstract: This study developed a high-performance cataluminescence (CTL) sensing platform based on Dy?O?/La?O? rare-earth composite oxides for specific detection of 1,2-epoxypropane (PO). Through optimized composition regulation of the rare-earth oxides, the Dy2O3/La2O3 heterointerface demonstrated remarkable synergistic catalytic effects, achieving both high sensitivity (LOD = 82.8 μM) and exceptional selectivity (10-fold higher response to PO than interferents). Under optimal conditions (detection wavelength: 575 nm; temperature: 360 °C; gas flow rate: 320 mL·min?1), the CTL intensity showed excellent linear correlation with PO concentration (y = 9701.25x + 15085.19, R2 = 0.9969), with an ultralow detection limit (8.28×10?? mol·L-1). The sensing system exhibited outstanding stability (RSD < 3% over 11 cycles) and satisfactory recovery rates (96-108%). A "photoexcitation-oxygen activation-selective oxidation-characteristic luminescence" sensing mechanism was proposed. This work provides a novel strategy for developing rare-earth oxide-based sensing materials and offers an innovative solution for environmental VOC monitoring.

Key words: Rare-earth composite oxides, Interfacial synergistic effect, Propylene oxide detection; Cataluminescence sensor, Gas-sensing reaction mechanism