Developing the triethylamine sensor with excellent sensitivity and selectivity is important for detecting the triethylamine concentration change in the environment. In this work, flower-like CeO₂-SnO₂ composites with different contents of CeO₂ were successfully synthesized by the one-step hydrothermal reaction. Some characterization methods were used to research the morphology and structure of the samples. Gas-sensing performance of the CeO₂-SnO₂ gas sensor was also studied and the results show that the flower-like CeO₂-SnO₂ composite showed an enhanced gas-sensing property to triethylamine compared to that of pure SnO₂. The response value of the 5 wt.% CeO₂ content composite based sensor to 200 ppm triethylamine under the optimum working temperature (310 °C) is approximately 3.8 times higher than pure SnO₂. In addition, CeO₂-SnO₂ composite is also significantly more selective for triethylamine than pure SnO₂ and has better linearity over a wide range of triethylamine concentrations. The improved gas-sensing mechanism of the composites toward triethylamine was also carefully discussed.

Methane detection is extremely difficult, especially at low temperatures, due to its high chemical stability. Here, WO₃ nanosheets loaded with SnO₂ nanoparticles with a particle size of about 2 nm were prepared by simple impregnation and subsequent calcination using SnO₂ and WO₃·H₂O as precursors. The response of SnO₂-loaded WO₃ nanosheet composites to methane is about 1.4 times higher than that of pure WO₃ at the low optimum operating temperature (90 °C). Satisfying repeatability and long-term stability are ensured. The dominant exposed (200) crystal plane of WO₃ nanosheets has a good balance between easy oxygen chemisorption and high reactivity at the dangling bonds of W atoms, beneficial for gas-sensing properties. Moreover, the formation of a n–n type heterojunction at the SnO₂-WO₃ interface and additionally the increase of specific surface area and defect density via SnO₂ loading enhance the response further. Therefore, the SnO₂-WO₃ composite is promising for the development of sensor devices to methane.