Au/PVC composite—a new material for solid-state gas sensors: Detection of nitrogen dioxide in the air

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• 作者：Hohercá ; ková ; Zuzana ; Opekar ; Franti&scaron ; ek
• 关键词：Gold electrode ; Composite material ; Solid polymer electrolyte ; Amperometric gas sensor ; Solid-state sensor ; Nitrogen dioxide
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2004
• 出版时间：February 1, 2004
• 年：2004
• 卷：97
• 期：2-3
• 页码：379-386
• 全文大小：235 K

文摘

A new composite material for indicator electrodes of solid-state electrochemical gas sensors was prepared by dispersion of a fine gold powder in a highly plasticized PVC matrix containing a hydrophobic electrolyte (Au/PVC electrode). The material consists of clusters of gold particles partially protruding from the polymer matrix into the gaseous phase. The composite, functioning both as a solid polymer electrolyte and as an indicator electrode, was tested in a planar amperometric NO₂ sensor in the air. The Au/PVC electrode behaves as an array of microelectrodes and exhibits a high catalytic activity. The response at −500mV versus Pt/air reference electrode was linearly dependent on the concentration over the whole tested range of 0.6–2.6ppm (v/v) NO₂. The sensitivity of determination amounted to 400nA/ppm, the detection limit was 50ppb, and the response time t₉₀ was 50s. The relative standard deviation of the sensitivity, calculated from 18 NO₂ determinations performed within 1 month, was 12 % . The Au/PVC electrode is applicable to continuously operating sensors monitoring the gaseous environment under conditions of slow variation in NO₂ content.