SnO2/carbon dots nanocomposite synthesized by one-pot solvothermal technique for high-sensitivity triethylamine gas sensors

The exploration of triethylamine (TEA) gas sensor with low cost, high response and low detection limit is still an urgent challenge. In this work, carbon dots (CDs) activated spherical Tin oxide (SnO2) nanocomposites were synthesized by a simple and friendly one-pot hydrothermal strategy, and CDs with rich functional groups are in-situ introduced into SnO2. SnO2/CDs composites were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy, etc. The gas sensing properties of SnO2/CDs and SnO2 for triethylamine (TEA) were systematically investigated. The sensor based on SnO2/CDs exhibits a highly sensitive response, good selectivity, repeatability and long stability. It shows the response (Ra/Rg = 55) to 100 ppm TEA is approximately 1.8 times that of SnO2 sensor. More attractively, the detection limit of the SnO2/CDs composite to TEA is 90 ppb, which is 6.7 times that of SnO2. The significantly improved TEA sensing performance of SnO2/CDs sensing material is mainly attributed to the formation of heterojunction and the increased active sites due to the introduction of CDs.