Oxygenated VOC Detection Using SnO₂ Nanoparticles with Uniformly Dispersed Bi₂O₃

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.