Enhanced ethanol sensing performance for chlorine doped nanocrystalline LaFeO3-δ powders by citric sol-gel method
Enhanced ethanol sensing performance for chlorine doped nanocrystalline LaFeO3-δ powders by citric sol-gel method
复制标题
柠檬酸溶胶-凝胶法增强氯掺杂纳米晶LaFeO3-δ粉末的乙醇传感性能
DOI：
10.1016/j.snb.2017.05.153
复制
发表时间：
2017-11-01
影响因子：
8.4
通讯作者：
Zhang, Yongjia
中科院分区：
文献类型：
--
作者：
Cao, Ensi;Wang, Huihui;Zhang, Yongjia
采用柠檬酸溶胶-凝胶法制备了LaFeO_3-xClx(x=0，0.15，0.3和0.6)粉末。总体而言，氯掺杂的引入增加了薄膜的平均微晶尺寸和晶粒尺寸，降低了材料的本征电阻，提高了材料的酒敏性能。当x=0.6时，传感器在136℃的最佳工作温度下获得了79.2-200ppm乙醇的最佳气体响应，表现出比其他传感器更好的传感性能，在最佳工作温度下具有良好的稳定性、气体响应、选择性、响应和恢复时间。X射线衍射和X射线光电子能谱分析表明，氯掺杂主要以Fe-Cl键的形式存在于晶格和表面，无论是在晶格中还是表面，都比La-Cl键更有利于形成。在XPS结果的指导下，对FeO端基LaFeO_3(010)表面C_2H_5OH气敏过程进行了从头算计算，结果表明，氯掺杂LaFeO_3(010)表面吸附位置和晶格中的氧被氯取代是提高LaFeO_3的乙醇敏感性能的原因。(C)2017爱思唯尔B.V.保留所有权利。
LaFeO3-xClx (x=0, 0.15, 0.3 and 0.6) powders were prepared by citric sol-gel method. On the whole, the introduction of chlorine dopant results in the increase of average crystallite size and grain size, the reduction of intrinsic resistance, and overall enhancement of ethanol sensing performance. The best gas response of 79.2-200 ppm ethanol at prime working temperature of 136 degrees C was achieved by the sensor with x=0.6, which exhibited superior ethanol sensing performance to other sensors with good stability, gas response, selectivity, short response and recovery time at prime working temperature. XRD and XPS results show that chlorine dopant mainly exists in the form of Fe-Cl bond in the lattice and on the surface, which are more favorable to form than the La-Cl bond either in the lattice or on the surface. ab initio calculations on the process of gas sensing to C2H5OH on FeO-terminated LaFeO3 (010) surface were performed under the guidance of XPS result, which indicate that the substitution of oxygen by chlorine both at the surface adsorption site and in the lattice should be responsible for the enhanced ethanol sensing performance of the chlorine doped LaFeO3. (C) 2017 Elsevier B.V. All rights reserved.