Titanium Dioxide-Yttrium(III)-Oxide Composite Based Cataluminescence Gas Sensor for Fast Detection of Propylene Oxide

Abstract

Abstract By using nano TiO2-Y2O3 as catalyst, cataluminescence (CTL) phenomenon of propylene oxide (PO) was studied, and it was found that the sensor has high sensitivity and good selectivity for the detection of propylene oxide. The common volatile organic compounds (VOCs) such as acetone, acetaldehyde and benzene show no response to the catalysis of TiO2-Y2O3. Based on this phenomenon, a propylene oxide CTL sensor was designed. The ratio of TiO2 and Y2O3 and the annealed temperatures of the composites were optimized. It was found that when the mass ratio of TiO2 and Y2O3 was 1:3 and the annealed temperature was 500 °C, the catalytic materials showed the best performance. 0.3 L min−1 of carrier gas flow rate, 490 nm of detection wavelength and 197 °C of working temperature were selected as the optimal working conditions, and under the optimized conditions, the quantitative analysis was performed and CTL intensity was linearly correlated with PO concentration from 4.5 mg L–1 to 1375 mg L–1 with a detection limit (3σ) of 1.25 mg L–1. The sensor was used for quantitative analysis and real-time monitoring of propylene oxide residues in fumigation cereals. The result was consistent with that analyzed by gas chromatography. The CTL sensor proposed here had many merits such as high sensitivity, rapidity and simple operation and had potential application prospects in the rapid detection of propylene oxide in food. At last, the mechanism of catalytic oxidation of PO was discussed as well.