Electrochemical Ammonia Gas Sensing in Nonaqueous Systems: A Comparison of Propylene Carbonate with Room Temperature Ionic Liquids

Abstract

First, the direct and indirect electrochemical oxidation of ammonia has been studied by cyclic voltammetry at glassy carbon electrodes in propylene carbonate. In the case of the indirect oxidation of ammonia, its analytical utility of indirect for ammonia sensing was examined in the range from 10 and 100 ppm by measuring the peak current of new wave resulting from reaction between ammonia and hydroquinone, as function of ammonia concentration, giving a sensitivity 1.29 Â 10 À7 A ppm À1 (r 2 ¼ 0.999) and limit-of-detection 5 ppm ammonia. Further, the direct oxidation of ammonia has been investigated in several room temperature ionic liquids (RTILs), namely 1-butyl-3-methylimidazolium tetrafluoroborate ([C 4 (r 2 ¼ 0.999) for all three ionic liquids, showing that the limit of detection was ca. ten times larger than that in propylene carbonate since ammonia in propylene carbonate might be more soluble in comparison with RTILs when considering the higher viscosity of RTILs.

Towards Mixed Fuels: The Electrochemistry of Hydrazine in the Presence of Methanol and Formic Acid

“…[7][8][9] The electrochemical oxidation of hydrazine, N 2 H 4 , in aqueous media at platinum electrodes is known to proceed as a fourelectron process [Eq. (1)…”

Surface acoustic wave ammonia sensor based on ZnO/SiO2 composite film

“…Among different kinds of ammonia gas sensors, such as semiconductor sensors [25,26], electrochemical sensors [27], QCM sensors [28,29] and SAW sensors [30,31], SAW sensors have superior performance due to high sensitivity, high stability, high accuracy and low cost. Generally, a surface acoustic wave (SAW) has a high acoustic energy density on the top-surface of piezoelectric substrate within one or two wavelengths.…”

A Robust Flexible Electrochemical Gas Sensor Using Room Temperature Ionic Liquid

“…Utilizing electrochemical measurement techniques, RTILs are capable of sensing a variety of environmental gases, including oxygen [12]- [17], ambient toxic gases (e.g. NO 2 [18], NO [19], NH 3 [20], H 2 S [21]), and volatile organic compounds (VOCs) [22], [23].…”