Development of cataluminescence sensor system for benzene and toluene determination

A novel and sensitive gas sensor was proposed for the determination of benzene and toluene based on its cataluminescence (CTL) by oxidation in the air on the surface of coral-like TiO2/SnO2 nanoparticles. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) were employed to characterize the as-prepared samples. The luminescence characteristics and the optimal conditions were investigated in detail under the optimized conditions. In gas-sensing measurements, benzene and toluene were employed as target analytes. The results show that the gas sensor based on the TiO2/SnO2 nanostructures exhibited outstanding cataluminescence (CTL) properties such as stable intensity, high signal/noise values, short response and remarkably improved sensitivity compared with pure SnO2 nanostructures. Additionally, a principal component analysis method was used to investigate the recognizable ability of the presented CTL sensor, it is found that benzene and toluene can be distinguished clearly. The fascinating gas-sensing properties including enhanced sensitivity, selectivity, stability and recognizable ability enable the presented TiO2/SnO2 nanocomposites to be a promising candidate for fabricating cataluminescence (CTL) gas sensor which can be applied for detecting environmental gas contaminants. The mechanism for the improved performance was also discussed based on the experimental results.