Nanoscale Pt thin film sensor for accurate detection of ppm level hydrogen in air at high humidity

SENSORS AND ACTUATORS B-CHEMICAL

卷:258

Article

Tanaka, Takahisa¹  Hoshino, Shinsuke¹  Takahashi, Tsunaki¹  Uchida, Ken¹ 

[1] Keio Univ, Fac Sci & Technol, Dept Elect & Elect Engn, 3-14-1 Hiyoshi, Yokohama, Kanagawa 2238522, Japan

关键词: Platinum;    Hydrogen;    Adsorption;    Humidity;    Scattering;    Sensor;   

DOI  :  10.1016/j.snb.2017.11.115

来源: Elsevier

【 摘 要 】

Hydrogen is an important biomarker for the human digestive system. However, accurate detection of ppm-level hydrogen in breath is difficult due to the competing detection of high concentration water. We fabricated Pt thin films that respond to hydrogen in air at concentrations as low as 500 ppb. In both dry and humid air, these films have almost identical response to hydrogen, i.e., their resistance decreases linearly with increasing hydrogen concentration regardless of relative humidity. Even at high relative humidity, these Pt thin films can detect ppm-level hydrogen. Furthermore, it was strongly suggested that these films can be applied to low-level hydrogen in the air expired by a healthy human. Based on the chemical kinetics, namely the adsorption and desorption of hydrogen and oxygen, the sensor response is quantitatively described by relating the hydrogen surface coverage to the magnitude of electron scattering at the Pt surface. The proposed model successfully reproduces the effects of hydrogen concentration and time on the sensor response, particularly at hydrogen concentrations below 20 ppm. Based on this model, these Pt thin film sensors have the potential to detect 1 ppm hydrogen in expired air within 30 s. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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