Volume-doped cobalt titanates for ethanol sensing: An impedance and X-ray absorption spectroscopy study

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• 作者：Clemens J. Belle ; G眉nter E. Wesch ; Stefan Neumeier ; M. Janeth Lozano-Rodr铆guez ; Andreas C. Scheinost ; Ulrich Simon
• 关键词：Cobalt titanate (CoTiO3) ; Volume doping ; Chemiresistor (resistive gas sensor) ; Ethanol (C2H5OH) sensitivity ; Impedance spectroscopy (IS) ; Extended X-ray absorption fine structure (EXAFS)
• 刊名：Sensors and Actuators B: Chemical
• 出版年：1 March, 2014
• 年：2014
• 卷：192
• 期：Complete
• 页码：60-69
• 全文大小：2124 K

文摘

The dynamic C₂H₅OH sensitivity of ilmenite-type cobalt titanates volume-doped by 2 at% Li, Na, K, Sb, La, Sm, Gd, Ho and Pb was systematically studied with respect to exhaust monitoring. Therefore, the p-type semiconducting CoTiO₃ materials were characterized as resistive gas sensors via high-throughput impedance spectroscopy toward 5-200 ppm C₂H₅OH at 300-500 掳C. The best performing materials were tested further by time-resolved and long-term measurements whereby the CoTiO₃ volume-doped with K exhibited an outstanding overall performance. X-ray absorption spectroscopy on this particular material gave evidence that the local structure around Co and Ti remains unaffected by the doping despite of a slight increase in static disorder. Hence, the effect of K doping does not originate from alteration in the metal-to-oxygen interaction as expected from previous findings.