利用模板法和溶胶-凝胶法分别制备了 SnO2和 LaFeO3纯材料,并检测了纳米复合材料 SnO2/LaFeO3对CO 的气敏性能。在实验过程中,观察到纳米复合材料85％SnO2＋15％LaFeO3(85Sn-La)及90％SnO2＋10％LaFeO3(90Sn-La)在检测CO 时出现了一个反常现象,通常CO 表现为还原性气体的性质,然而在T≤200℃的温度范围内,与CO 的作用增加了复合氧化物85Sn-La及90Sn-La的电阻,而这一现象只在与氧化性气体反应时观察过。这种在特定环境下,n型材料与还原性气体(施主)作用时,其导电特征表现为与氧化性气体(受主)作用时相同的现象称为类受主现象。类受主现象只在低温阶段被观察到,且复合氧化物85 Sn-La表现最为明显。利用温度、气氛与材料表面的交互作用来解释所观察到的实验现象：在低温情况下,CO 与材料表面的吸附氧及羟基发生反应,增加了表面的电荷,降低了材料表面的导电性,因而表现为类受主现象。
Template method and sol-gel method have been used to synthesize SnO2 and LaFeO3 ,and the CO gas sensing properties of the as-prepared SnO2/LaFeO3 nanocomposites have been studied.During the test,an a-nomalous phenomenon has been observed:nanocomposites 85%SnO2+15%LaFeO3(85Sn-La)and 90%SnO2+10%LaFeO3 (90Sn-La)showed a decreased conductivity towards interaction with CO at temperature lower than 200 ℃,which we call it an acceptor-like behavior.
Acceptor-like behavior has been observed at low temperature only and shows a maximum acceptor effect for nanocomposite 85Sn-La.The interaction between temperature;gas and the material surface has been proposed to explain the observed behavior.At low temperature,a reaction between CO and hydroxyl absorbed on the sur-face will occur,resulting in the increase of the material surface charge and the decrease of the conductivity.
参考文献
| [1] | Hagemeyer A;Hogan Z;Schlichter M;Smaka B;Streukens G;Turner H;Volpe A;Weinberg H;Yaccato K.High surface area tin oxide[J].Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications,20071(1):139-148. |
| [2] | Sanju Rani;Somnath C. Roy;M.C. Bhatnagar.Effect of Fe doping on the gas sensing properties of nano-crystalline SnO_2 thin films[J].Sensors and Actuators, B. Chemical,20071(1):204-210. |
| [3] | B.Levasseur;S.Kaliaguine.Methanol oxidation on LaBO3 (B = Co,Mn,Fe) perovskite-type catalysts prepared by reactive grinding[J].Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications,20081/2(1/2):29-38. |
| [4] | Jong Won Yoon;Maria Luisa;Grilli;Elisabetta Di Bartolomeo;Riccardo Polini;Enrico Traversa.The NO{sub}2 response of solid electrolyte sensors made using nano-sized LaFeO{sub}3 electrodes[J].Sensors and Actuators, B. Chemical,20011/3(1/3):483-488. |
| [5] | Wang, X.;Qin, H.;Sun, L.;Hu, J..CO_2 sensing properties and mechanism of nanocrystalline LaFeO_3 sensor[J].Sensors and Actuators, B. Chemical,2013:965-971. |
| [6] | Gurlo A;Sahm M;Oprea A;Barsan N;Weimar U.A p- to n-transition on alpha-Fe2O3-based thick film sensors studied by conductance and work function change measurements[J].Sensors and Actuators, B. Chemical,20042(2):291-298. |
| [7] | Rani S;Bhatnagar MC;Roy SC;Puri NK;Kanjilal D.p-Type gas-sensing behaviour of undoped SnO2 thin films irradiated with a high-energy ion beam[J].Sensors and Actuators, B. Chemical,20081(1):35-39. |
| [8] | Wang, JX;Sun, XW;Yang, Y;Wu, CML.N-P transition sensing behaviors of ZnO nanotubes exposed to NO2 gas[J].Nanotechnology,200946(46):465501:1-465501:4. |
| [9] | G. Korotcenkov;V. Brinzari;V. Golovanov;A. Cerneavschi;V. Matolin;A. Tadd.Acceptor-like behavior of reducing gases on the surface of n-type In_2O_3[J].Applied Surface Science: A Journal Devoted to the Properties of Interfaces in Relation to the Synthesis and Behaviour of Materials,20041/4(1/4):122-131. |
| [10] | Kim YS;Hwang IS;Kim SJ;Lee CY;Lee JH.CuO nanowire gas sensors for air quality control in automotive cabin[J].Sensors and Actuators, B. Chemical,20081(1):298-303. |
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