Bi2O3 particles are introduced as foreign additives onto SnO2 nanoparticles (NPs) surfaces for the efficient detection of oxygenated volatile organic compounds (VOCs). Bi2O3-loaded SnO2 materials are prepared via the impregnation method followed by calcination treatment. The abundant Bi2O3/SnO2 interfaces are constructed by the uniform dispersion of Bi2O3 particles on the SnO2 surface. The results of oxygen temperature-programmed desorption suggest that Bi2O3-loaded SnO2 samples display improved surface oxygen ions than neat-SnO2 NPs. As a result, the gas sensor based on 1 mol% Bi2O3-loaded SnO2 (1Bi-L-SnO2) composites shows significantly higher sensitivity and a faster response speed toward various oxygenated VOCs compared with SnO2, especially at 200 °C and 250 °C. The results of catalytic combustion and temperature-programmed reaction measurements reveal the dominant role of adsorption and partial oxidation during ethanol combustion on SnO2 and 1Bi-L-SnO2 surfaces. In this case, the improvement in the sensing performance of the 1Bi-L-SnO2 sensor can be associated with the increase in surface oxygen ions at Bi2O3/SnO2 interfaces. The results confirm the significant role of surface functionalization for sensing materials. The obtained outstanding sensing performance provides the potential application for the simultaneous detection of total oxygenated VOCs in practice.
Keywords: Bi2O3-loading; SnO2 nanoparticles; interface; oxygenated VOC detection; surface oxygen ions.