Design and understanding of SnO2 architecture decorated by MoS2 quantum dots for enhancing triethylamine sensing

The size effect through quantum dots is an effective method to improve the performance of gas sensors. This paper reports the design of a triethylamine sensor based on a SnO 2 -MoS 2 heterojunction structure. The porous SnO 2 was synthesized using a polystyrene microsphere template and then loaded with MoS 2 quantum dots (MoS 2 QDs) by the impregnation method. The gas-sensitizing properties of the prepared sensors were systematically investigated. Compared with the single SnO 2 and MoS 2 gas sensing materials, the SnO 2 -MoS 2 sensor showed higher selectivity to triethylamine at the optimal operating temperature of 160 °C, and the response performance was improved by 192 %. The results show that the SnO 2 -MoS 2 heterojunction improves the sensing performance due to its unique pore structure, oxygen vacancies and n-n heterojunction. In addition, the energy band structure and triethylamine sensing mechanism of SnO 2 -MoS 2 heterojunctions were analyzed by density functional theory. This work provides significant value for the study of gas-sensitive properties and triethylamine sensors of SnO 2 -MoS 2 QDs composites. • The porous SnO 2 architecture decorated by MoS 2 quantum dots was facilely synthesized. • The optimal operating temperature of the sensor is 160℃. • The simulated electrostatic potential of triethylamine is used to understand the response mechanism.