Highly sensitive and selective toluene sensor based on Ce-doped coral-like SnO2

Abstract

Coral-like SnO₂ nanostructure was synthesized via a simple hydrothermal treatment in the presence of glucose. The characterization results showed that the size of coral-like SnO₂ powders is about 13 nm with porous structure. The special surface area and the average size of pores are about 46.9 m² g⁻¹ and 7.61 nm, respectively. Subsequently, we investigated the gas-sensing properties of the sensors based on the coral-like SnO₂. We chose CeO₂ as a dopant and made three CeO₂ doped sensors with 0.5%, 1.5%, and 2.5% for the mole ratio of Ce to Sn. The gas sensing tests indicated that CeO₂ as the dopant can significantly enhance the gas selectivity toward toluene, and the sensor with 1.5% mole ratio showed the highest sensitivity toward toluene at 190 °C, which is much higher than that toward other VOC gases such as ethanol, acetone, and formaldehyde. The efforts in the research have proved that the CeO₂ doped SnO₂ could be a potential candidate of highly sensitive and selective gas sensors for toluene.