Enhanced ethanol sensing properties of SnO2/CdSnO3 heterostructure via a facile carbon incorporation strategy

The efficient detection of ethanol is crucial for environmental monitoring and human health. However, metal oxide semiconductors (MOS) such as CdSnO 3 often suffer from low sensitivity, poor selectivity, and high detection limits. Doping and heterostructure construction have been demonstrated as effective strategies to enhance the gas-sensing properties of MOS. In this work, a carbon-modified SnO 2 /CdSnO 3 heterostructure was synthesized by a one-step glucose-assisted hydrothermal method. Among them, CSO@C*6 based sensor exhibits the highest response toward ethanol gas. Its response value to 100 ppm ethanol is 47.52 at optimal working temperature of 237.5 ℃, 5.7 times higher than that of pure CdSnO 3 (8.27). Besides high response, the CSO@C*6 based sensor represents excellent selectivity, rapid response speed (1 s) and extremely low theoretical LOD to ethanol (2.81 ppb). The ethanol sensing performance of the CSO@C*6 was significantly enhanced, mainly due to (1) its high specific surface area, (2) carbon-induced oxygen enrichment effect and its hydrophobicity, and (3) the formation of n-n heterojunction. This work proposes a facile approach for synthesizing heterostructures and demonstrates the potential of carbon modification in improving gas-sensing performance.