Novel catalytic gas sensors based on functionalized nanoparticle layers
Novel catalytic gas sensors based on functionalized nanoparticle layers
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DOI：
10.1016/j.snb.2012.07.057
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发表时间：
2012-11-01
影响因子：
8.4
通讯作者：
Baeumer, M.
中科院分区：
文献类型：
--
作者：
Altmann, L.;Sturm, H.;Baeumer, M.
本文介绍了一种热氢气传感器，其具有基于十二胺 (DDA) 封端的铂纳米粒子（DDA 封端的 PtNPs）薄膜制成的新型催化层。这些纳米颗粒通过胶体合成方法制备，由于其配体外壳，具有更高的稳定性和对基材更好的粘附性，并且团聚程度较低。传感元件由两个热电堆和放置在氮化硅膜上的中央加热器组成，其工作原理是热电效应。通过将配体封端的纳米颗粒沉积在一个热电堆的加热结上，由于催化 H-2 氧化过程中释放的反应热导致热电堆热电压的变化，可以检测到氢气。第二个热电堆用作参考元件。为了确定有机配体对传感器活性的影响，未受保护的铂纳米粒子（未受保护的PtNP）也被用作催化剂。这两种方法，即未覆盖和功能化的铂纳米粒子，都已被表征并暴露于不同的氢浓度。结果表明，未受保护的纳米颗粒强烈团聚，导致输出信号较低，而配体封端的纳米颗粒则观察到线性且可重复的输出信号，灵敏度高达 6.4 mV/1000 ppm 氢。 (C) 2012 Elsevier B.V. 保留所有权利。
A thermal hydrogen gas sensor with a new type of catalytic layer based on films made of dodecylamine (DDA) capped platinum nanoparticles (DDA capped PtNPs) is presented here. These nanoparticles - prepared by a colloidal synthetic approach - offer, due to their ligand shell, a higher stability and a better adhesion to substrates and show lower agglomeration. Working principle of the sensing elements, consisting of two thermopiles and a central heater placed on a silicon nitride membrane, is the thermoelectric effect. By deposition of the ligand capped nanoparticles on the heated junction of one thermopile, hydrogen can be detected due to a change of the thermopile thermovoltage resulting from the reaction heat released during catalytic H-2 oxidation. A second thermopile was used as a reference element. In order to determine the influence of the organic ligands on the sensor activity, unprotected platinum nanoparticles (unprotected PtNPs) were also used as catalyst. Both approaches, the uncovered and functionalized platinum nanoparticles, have been characterized and exposed to different hydrogen concentrations. Results point towards a strong agglomeration of unprotected nanoparticles resulting in low output signals, whereas for the ligand capped nanoparticles a linear and reproducible output signal with a sensitivity up to 6.4 mV/1000 ppm hydrogen was observed. (C) 2012 Elsevier B.V. All rights reserved.