贵金属Pd离子掺杂纳米ZnSnO_3的氢敏性能及掺杂机理  

Hydrogen Sensing Properties and Doping Mechanism of Nano ZnSnO_3 Doped with Noble Metallic Pd Ions

作　　者：曾文[1] 刘天模[1,2] 雷晓飞[1] 甘浩宇[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400030 [2]重庆大学国家镁合金材料工程技术研究中心,重庆400030

出　　处：《纳米技术与精密工程》2010年第6期527-531,共5页Nanotechnology and Precision Engineering

基　　金：国家留学基金委公派研究生项目(留金出20093012);重庆市自然科学基金资助项目(CSCT2005BA4015);重庆大学中央高校基本科研业务经费资助项目(CDJXS10131154)

摘　　要：为了提高ZnSnO3的氢敏性能,以共沉淀法制备ZnSnO3并对其进行了贵金属Pd2+掺杂.采用X射线衍射仪(X-ray diffraction,XRD)及透射电镜(transmission electron microscopy,TEM)对制备的气敏材料进行结构及形貌表征,并使用静态配气法测试了掺杂前后ZnSnO3的氢敏性能.结果表明:掺杂Pd2+可显著提高ZnSnO3的氢敏性能.在工作温度为240℃、浓度为300×10-6的条件下,Pd2+掺杂纳米ZnSnO3对氢气的灵敏度为12,是未掺杂时的3倍.基于第一性原理探讨气敏机理,计算结果表明:Pd2+掺杂改变了ZnSnO3能带间的电子运动状态,使ZnSnO3费米能级由0.725 eV移动到1.035 eV,在费米能级附近产生新的电子峰,使其电导性能在气敏反应过程中改变更为明显.Pd2+掺杂还使ZnSnO3表面吸附氧的能力显著增加,对提高氢敏性能起到了关键作用.To improve the hydrogen sensing properties of ZnSnO3,nano ZnSnO3 doped with Pd ions was prepared using coprecipitation method in this paper.The microstructure and morphology of the prepared gas-sensitive materials were characterized using X-ray diffraction（XRD） and transmission electron microscopy（TEM）,respectively.The hydrogen sensing properties of the undoped and Pd2＋ doped ZnSnO3 were investigated using the static volumetric method.Results show that doping of Pd ions can significantly improve the hydrogen sensing properties of ZnSnO3.At the operating temperature of 240 ℃ and with the concentration of 300×10-6,the sensitivity of Pd2＋-doped ZnSnO3 to hydrogen is 12,which is three times that of the undoped sample.Further investigation of the gas sensing mechanism based on first-principles was conducted and calculation results indicate that the electronic athletic state of ZnSnO3 is changed after Pd2＋ was doped.The Fermi energy shifted from 0.725 eV to 1.035 eV and a new electronic peak was formed near the Fermi energy,leading to greater variation of conductivity in the gas-sensing reaction process.In addition,doping of Pd2＋ remarkably enhances the competence of oxygen adsorption on the surface of ZnSnO3,which plays a crucial role in improving the hydrogen sensing properties of ZnSnO3.

关 键 词：ZnSnO3 Pd2+掺杂 氢敏性能 第一性原理 

分 类 号：TB383.1[一般工业技术—材料科学与工程]