ppb level triethylamine detection of yolk-shell SnO2/Au/Fe2O3 nanoboxes at low-temperature

Yolk-shell nanostructures with high specific surface area and more active areas become the development direction of gas sensors. In this work, yolk-shell SnO₂/Au/Fe₂O₃ nanoboxes with specific surface area of 38.3 m² g⁻¹ were successfully prepared. The size of Fe₂O₃ nanocubes was about 300 nm, the thickness of SnO₂ was about 20 nm and the diameter of Au nanoparticles was about 12 nm. Benefiting from the distinctive structure and catalytic activity of precious metals, the as-prepared SnO₂/Au/Fe₂O₃ yolk-shell nanostructures showed outstanding response to triethylamine (TEA) gas at 240 °C. The response value to 100 ppm TEA gas was 126.84, which was about 6 times and 14 times of the Au/Fe₂O₃ and Fe₂O₃ samples. In addition, yolk-shell SnO₂/Au/Fe₂O₃ nanoboxes also exhibited a low detection limit (50 ppb), good response and recovery character (7/10 s). This experiment provided novel ideas for the design of new nanostructures for gas sensors.