Quantum Dots Sensitized SnO₂ Based Gas Sensor With UV-Enhanced

Since harmful gases may cause acid rain and photochemical smog,high-performance room temperature NO₂sensors are urgently needed to detect or monitor ppb levels of NO₂.In the atmosphere UV excitation can activate chemical reactions at lower operating temperatures,making room temperature detection possible.At the same time,the one-dimensional structure and quantum dots are favorable for carrier migration and activation of gas because of their large specific surface area and high surface permeability.This paper mainly focuses on one-dimensional structure,quantum dots,ultraviolet excitation,room temperature and other directions.The main tasks include:(1)Three different SnO₂nanostructures:SnO₂nanospheres,SnO₂nanosheets and SnO₂nanowires,were synthesized by three methods.A variety of structural and morphological characterization and gas sensing properties were tested,including XRD,SEM,TEM,PL.Compared with the gas sensing properties of the three structures,the best one-dimensional SnO₂nanowires were selected for recombination.(2)The one-dimensional SnO₂nanowires were combined with ZnO by aging method,which was characterized and gas-sensitive by UV excitation.The performance of ZnO/SnO₂nanowires composites is lower than that of pure SnO₂nanowires,and quantum dots are chosen as sensitizers for the composites.(3)The one-dimensional SnO₂nanowires were combined with ZnO quantum dots by aging method control each proportion to make the sensor performance higher.The optimum gas sensing performance of the sensor is obtained under ultraviolet excitation.Gas sensing properties of SZQ1%composite sensors at room temperature are explored in this paper.Using one-dimensional SnO₂nanowires as precursors to ZnO quantum dots,different gases were detected under ultraviolet excitation.Gas sensing results show that the combination of a certain proportion of ZnO quantum dots can effectively improve the gas sensing performance of semiconductor oxide gas sensors,and UV excitation can significantly improve the sensing performance of composite materials.It provides practical support for room temperature gas sensors excited by ultraviolet light in the future.