Response characteristics of a highly sensitive gas sensor using a titanium oxide nanotube film decorated with platinum nanoparticles
Response characteristics of a highly sensitive gas sensor using a titanium oxide nanotube film decorated with platinum nanoparticles
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DOI：
10.1016/j.snb.2020.128525
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发表时间：
2020-10-15
影响因子：
8.4
通讯作者：
Niwano, Michio
中科院分区：
文献类型：
--
作者：
Abe, Hiroyuki;Kimura, Yasuo;Niwano, Michio
通过钛金属阳极氧化形成的二氧化钛纳米管薄膜在高温下对各种气体表现出高反应活性。到目前为止，已经提出了多种使用二氧化钛纳米管薄膜的气体传感器。此前，我们提出了一种利用钛微电极局部阳极氧化制备的二氧化钛纳米管薄膜的微型气体传感器。在这项研究中，为了改善基于二氧化钛纳米管的微型气体传感器的响应特性，我们使用原子层沉积技术用铂纳米粒子等催化贵金属对二氧化钛纳米管薄膜进行修饰。我们证实，由于铂的修饰，对氢气和一氧化碳气体的灵敏度显著提高。氢气的检测极限处于亚ppm范围。基于朗缪尔吸附模型详细分析了氢气和一氧化碳气体的响应特性。发现当气体浓度增加时，吸附模式从薄膜顶表面吸附转变为二氧化钛纳米管内壁吸附。我们还表明，可以检测到含氧气和氮气的混合气体中微量的一氧化碳气体。
Titanium oxide nanotube thin films formed by anodic oxidation of titanium metal exhibit high reactivity towards various gases at high temperatures. To date, various types of gas sensors using titanium oxide nanotube films have been proposed. Previously, we proposed a microscale gas sensor with titanium oxide nanotube thin films fabricated by local anodization of titanium microelectrodes. In this study, to improve the response characteristics of titanium oxide nanotube-based microscale gas sensors, we decorated titanium oxide nanotube films with catalytic noble metals of platinum nanoparticles using atomic layer deposition technique. We confirmed that due to Pt decoration the sensitivity was significantly improved for hydrogen and carbon monoxide gases. The detection limit of hydrogen gas was found to be in the sub-ppm range. The response characteristics of hydrogen and carbon monoxide gases were analyzed in detail based on the Langmuir adsorption model. It was found that when the concentration of gas increased, the adsorption mode changed from adsorption on the top surface of the film to that on the inner wall of the titanium oxide nanotubes. We also show that the trace amounts of carbon monoxide gas in a mixed gas containing oxygen and nitrogen can be detected.