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Developments in Electrodes and Electrolytes of Dye-Sensitized Solar Cells
Published in Swee Ching Tan, Photosynthetic Protein-Based Photovoltaics, 2018
Ajay K. Kushwaha, Nagaraju Mokurala, Krishnaiah Mokurala, Siddhartha Suman
The counter electrode, also known as auxiliary electrode, is one of the essential components to complete the circuit in the electrochemical cell. The counter electrode should be inert in nature—for example, Pt, Au, graphite, glassy carbon kind of materials. The reason for the electrode to be inert is it should not participate in the reaction. In the DSSC, the current flows from working electrode to counter electrode; therefore, the surface area of the counter electrode must be higher than the working electrode. The area of the counter electrode should not become a limiting factor in the kinetics of the process. It can also be explained as the interface where the oxidized species present in the electrolyte solution are reduced.16 The counter electrode plays a vital role to support the redox mechanism, where counter electrode performs the reduction mechanism in the electrolyte thereby oxidizing the photovoltaic electrode. Usually, platinum-coated FTO glass substrate is used as a counter electrode because it offers better electron transfer in reverse order with less resistance. Graphite, carbon black17 and carbon nanotubes,17 and graphene18 on FTO have also been demonstrated as counter electrodes as discussed in Section 2.5.
Electrochemical Methods
Published in Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus, Environmental Chemical Analysis, 2018
Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus
The experiment is performed by the use of a three-electrode system. One electrode is the micro electrode at which the reaction takes place. A reference electrode, designed to produce a constant potential under a wide variety of conditions, is used as a standard against which to measure the potential being applied to the working electrode. A larger auxiliary electrode is used to carry current, so that no current is drawn through the reference electrode, to prevent that electrode from becoming polarized and changing its potential. The potential of the working electrode is gradually made more negative, until the potential is reached at which Pb2+ is reduced. At that point, a current will begin to flow, polarizing the working electrode. The current will rise as the reaction begins to occur, and it will stabilize at a limiting current which is governed by the original concentration of lead, Co.
Analytical Design of FET-Based Biosensors
Published in Suman Lata Tripathi, Sobhit Saxena, Sushanta Kumar Mohapatra, Advanced VLSI Design and Testability Issues, 2020
Khuraijam Nelson Singh, Pranab Kishore Dutta
They are usually made up of three main components [6]: Working electrode: It is an electrode in which the electrochemical reaction takes place.Reference electrode: It is a stable electrode which potential is used as a reference for potential measurement.Auxiliary electrode: It is an electrode that is used for completion of the circuit of the electrochemical cell.
Micro-machining through electrochemical discharge processes: a review
Published in Materials and Manufacturing Processes, 2020
Nitesh Kumar, Niladri Mandal, A. K. Das
Figure 3 shows the schematic view of the µ-ECDM set up for working on (a) non-conductive and (b) conductive materials. The basic difference between the two setups is that, in case of non-conductive materials, the counter electrode is used, while, in the second setup, power is directly applied on the workpiece due to its conductive nature.[55] In this section, while depicting spark generation, the workpiece has been considered as a non-conductive material. In this setup, two electrodes are used, i.e., tool electrode and counter-electrode. The tool electrode is smaller in size as compared to the counter electrode by nearly 100 times and their dimension ratio is approximately 1:100. The latter is also known as auxiliary electrode.[56] The direct current (DC) power source is used to maintain voltage, which can either be continuous or pulse in nature. In general, the negative terminal of the power source is connected to the tool, known as, cathode, while the positive terminal to the auxiliary electrode is called anode. A few researchers experimented with the reverse connection as well.[57] For this, non-conductive workpieces, such as glass, ceramics, etc., are submerged in an electrolyte. The electrolytes used have to be either acidic, alkaline or neutral in nature.[58] However, generally alkaline electrolyte is preferred. The gap between the tool electrode (cathode) and counter electrode (anode) is maintained at a distance of approximately 25–60 mm while the tool electrode is immersed inside the electrolyte at about a distance of nearly 1–2 mm[58] for a smooth machining process.