Comparison of Voltammetric Techniques for Ammonia Sensing in Ionic Liquids
MetadataShow full item record
© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. In electroanalytical chemistry, it is often observed that square wave voltammetry (SWV) and differential pulse voltammetry (DPV) are more sensitive techniques compared to linear sweep voltammetry (LSV), due to their method of sampling which minimises the charging current (non-faradaic processes). In this work, a comparison of the three techniques (LSV, DPV and SWV) is performed for ammonia (NH 3 ) gas oxidation (a chemically and electrochemically irreversible redox process) in an ionic liquid over a concentration range of 10–100 ppm. Four different platinum electrodes are employed: a screen-printed electrode (SPE), a thin-film electrode (TFE), a microarray thin-film electrode (MATFE) and a Pt microdisk electrode (µ-disk). Calibration plots (current vs concentration) for all three different electrochemical techniques on all four surfaces showed excellent linearity with increased concentrations of NH 3 gas and relatively low limits of detection (LODs). On the larger mm-sized surfaces (SPE and TFE), the current responses for LSV and SWV were quite similar, but DPV gave the lowest currents. Whereas for the smaller micron sized electrodes (MATFE and µ-disk), currents were of the order LSV > SWV > DPV, with LSV being far superior to the pulse techniques. These findings suggest that the pulse techniques of SWV and DPV may not be the optimum methods, particularly on microelectrodes, for the detection of analytes such as ammonia in RTILs.
Showing items related by title, author, creator and subject.
Electrospinning based fabrication and performance improvement of film electrodes for lithium-ion batteries composed of TiO<inf>2</inf> hollow fibersYuan, T.; Zhao, B.; Cai, R.; Zhou, Y.; Shao, Zongping (2011)Film electrodes composed of 1D TiO<inf>2</inf> or TiO<inf>2</inf>/Ag composite hollow fibers were fabricated by a coaxial electrospinning technique, and were applied as the anode of lithium-ion batteries free of any binder ...
Estimation of electrochemical noise impedance and corrosion rates from electrochemical noise measurements.Lowe, Alexander M. (2002)Electrochemical noise refers to the spontaneous fluctuations in potential and current that can be observed on a corroding metal. The use of electrochemical noise for obtaining information on the corrosion process generates ...
Chester, Ryan (2007)The first part of this thesis reports the synthesis of five calixarene molecules and their incorporation into ISEs as thallium(I) selective ionophores for use in clinical and environmental analysis. Four calixarene ...