PbS量子点/MoO3纳米带复合材料的低温气敏性能研究

Study on the Gas Sensing Properties of PbS Quantum Dots/MoO_3 Nanobelts at Low Temperature

采用液相法制备PbS量子点修饰MoO_3纳米带复合材料。利用XRD、FESEM、TEM、EDS等表征手段分析样品组成、结构与形貌,分别将MoO_3纳米带、PbS量子点、PbS量子点/MoO_3纳米带组装成陶瓷管气敏元件并测试其对NH_3的气敏性能。结果表明,在低温(20~100℃)下PbS量子点/MoO_3纳米带复合材料对NH3具有良好检测能力,最低测试限为10 ppm。由于PbS量子点均匀分布在MoO_3纳米带表面可形成异质结界面,这可有助于电子、空穴的分离,从而显著改善电子传输性能和气敏特性。

PbS quantum dots（ QDs） decorated MoO3 nanobelts were prepared by liquid phase method.The composition,structure and morphology of PbS QDs/MoO3 nanobelts were charactered by XRD,FESEM,TEM and EDS measurements. Gas sensors based on MoO3,PbS QDs and PbS QDs/MoO3 nanobelts were assembled using commercial ceramic tubes and their gas sensing properties towards NH3 were tested. The results show that gas sensors based on PbS QDs/MoO3 nanobelts have a good gas sensing response to NH3 at a relative low temperature range（ 20-100 ℃）,and the lowest detect limit is 10 ppm.PbS QDs are uniformly dispersed on the surface of the MoO3 nanobelts, and then the formed heterojunction interface may favor for the separation of electrons and holes,which will greatly improve their electron transfer ability and gas sensing performance.