Manipulating the gas-surface interaction between copper(II) oxide and mono-nitrogen oxides using temperature
Manipulating the gas-surface interaction between copper(II) oxide and mono-nitrogen oxides using temperature
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DOI：
10.1016/j.snb.2016.01.104
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发表时间：
2016-06-28
影响因子：
8.4
通讯作者：
Palzer, Stefan
中科院分区：
文献类型：
--
作者：
Kneer, Janosch;Woellenstein, Juergen;Palzer, Stefan
在这篇文章中，我们研究了不同温度下一氧化氮(NO)和二氧化氮(NO2)的表面反应对喷墨打印的p型半导体氧化铜(CuO)的影响。首次证明了气体诱导的CuO在NOx暴露下电导率的变化可以从氧化行为调整为还原行为，并且这种相互作用可以被有效地关闭。利用从氧化到还原转变的实验结果，我们讨论了潜在的表面反应，这对于基于金属氧化物的NOx气体传感器具有普遍的意义。我们证明了金属氧化物反应完全受控于NO/NO2随温度变化的化学平衡。基于这些结果，可以设计出温度调制方案来提高金属氧化物气体传感器的选择性。我们进一步表明，CuO材料体系能够检测到低水平的NO/NO2，两种氧化物的氧化反应在260℃时最强，还原反应在440℃时最强。由于该层的基线电阻率具有很高的稳定性，可以检测到低至200 ppb的浓度。(C)2016爱思唯尔B.V.保留所有权利。
In this contribution we investigate the effects of surface reactions of nitric oxide (NO) and nitrogen dioxide (NO2) on inkjet printed, p-type semiconducting copper(II) oxide (CuO) in different temperature regimes. For the first time we show that the gas-induced changes of the electrical conductivity of CuO upon NOx exposure may be tuned from oxidizing to reducing behavior and that the interaction may be effectively turned off. Using the experimental results of the transition from oxidizing to reducing characteristics we discuss the underlying surface reactions, which is of interest for metal-oxide based gas sensors for NOx in general. We demonstrate that the metal oxide reaction is solely governed by the temperature dependent chemical equilibrium of NO/NO2. Based on these results temperature modulation schemes to enhance the selectivity of metal-oxide gas sensors may be devised. We furthermore show that the CuO material system is able to detect low levels of NO/NO2, with a strongest oxidation response at 260 degrees C and a strongest reduction response at 440 degrees C for both oxides. Due to the high stability of the baseline resistivity of the layer, concentrations as low as 200 ppb may be detected. (C) 2016 Elsevier B.V. All rights reserved.