Understanding the Differences between a Quasi-Reference Electrode and a Reference Electrode

Authors: Angel AJ Torriero*

DOI: 10.23880/macij-16000144

Volume 3, Issue 3

Abstract

The terms “pseudo-reference electrode” and “quasireference electrode” are widely mentioned in the literature and used interchangeably or as synonyms. However, it is not clear about its meaning or the characteristics a system should have to be considered as a quasi-reference electrode. For example, if we search the Internet for a meaning we can find the following definition of quasi-reference electrode at the Royal Society of Chemistry web page: “An electrode based on a ferrocene or cobaltocene redox couple internal standard through which no appreciable current is allowed to flow and is used to observe or control the potential at a working electrode” [1]. Meanwhile, Bard and Faulkner define in their book a quasi-reference electrode as “just a metal wire, Ag or Pt, used with the expectation that in experiments where there is essentially no change in the bulk solution, the potential of this wire, although unknown, will not change during a series of measurements” [2]. Finally, a reference electrode designed for its use in non-aqueous solvents (e.g., an Ag metal wire immersed in an AgNO3 acetonitrile solution) is also named in some literature as a pseudo-reference electrode. All these definitions are describing completely different systems under the same name. Therefore, new researchers initiating in the electrochemistry field, in particular, and those initiating in the chemistry field, in general, may not understand the difference between these definitions, and more importantly, the differences between a pseudo-reference electrode (or a quasireference electrode) and an actual reference electrode.

Keywords: Pseudo-Reference Electrode; Literature; Non-Aqueous Solvents

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