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论文类型：期刊论文

发表时间：2017-11-01

发表刊物：SENSORS AND ACTUATORS B-CHEMICAL

收录刊物：SCIE

卷号：251

页面范围：885-893

ISSN号：0925-4005

关键字：LaFeO3; Sol-gel; XPS; Ethanol sensing; Chlorine doping; Ab initio calculation

摘要：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.