EP4689626A1

EP4689626A1 - A multiple disc electrode holder

Info

Publication number: EP4689626A1
Application number: EP24714570.9A
Authority: EP
Inventors: Sylwia Smarzewska; Dariusz Guziejewski
Original assignee: Uniwersytet Lodzki
Current assignee: Uniwersytet Lodzki
Priority date: 2023-04-06
Filing date: 2024-03-07
Publication date: 2026-02-11
Also published as: PL444330A1; PL248346B1; WO2024209287A1

Abstract

The invention relates to a multiple disc electrode holder comprising a cylindrical housing (1) having a through hole in the shape adapted to a conductive electrode carrier (2b) in the form of a double-tapered cylinder (2) rolled out so that its narrowest end is an electrical contact (2a) connecting the conductive electrode carrier (2b) to the potentiostat/electrical circuit, and then the conductive electrode carrier (2b) passes into a wider central portion of a cylinder (2), the second widest end of the conductive electrode carrier (2b) located at the bottom portion of the cylindrical housing (1) has n openings for n working material discs (4) which are disposed in these openings, wherein working material discs (4) are placed at an inside body (3) having n through holes dimensioned to a diameter of n working material discs (4), wherein the inside body (3) is made from chemically and electrically resistant material.

Description

A MULTIPLE DISC ELECTRODE HOLDER

The present invention relates to a multiple disc electrode holder intended for use in simultaneous measurements, which are particularly important in optimization and validation studies.
In modern electrochemical measurements, especially polarographic, amperometric and voltammetric measurements, a three-electrode system is used. The most important element is the working electrode, which controls the flow of the current during measurements. This kind of electrode is widely known in the literature (e. g. J. Wang, Analytical Electrochemistry, 3rd ed., Wiley-VCH, 2006, Hoboken or A. J. Bard, L. R. Faulkner, Electrochemical Methods: Fundamentals and Applications, 3rd ed., Wiley-VCH, 2022, Hoboken) in various versions and sizes (J. Jörissen, Practical Aspects of Preparative Scale Electrolysis, at Encyclopaedia of Electrochemistry (Ed.: A. J. Bard), 2007).
The most commonly used electrode type is in the form of a cylinder or disc of a conductive material such as precious metals, carbon materials or other conductive materials embedded in an inert, nonconductive material such as polymer or resin (D. M. Heard, A. J. J. Lennox, Electrode Materials in Modern Organic Electrochemistry, Angew. Chem. Int. Ed. 2020, 59, 18866). From one side, electrical contact is made to the connections in the electrical circuit along with the remaining elements of the measuring system and its control elements, on the other side, through the planar disk surface of the working material, there is a contact with the conductive solution (electrolyte), which is another element of the measuring system and guarantees the continuity of the electrical circuit through contact with the other electrodes (Bard, Allen J. ; Larry R. Faulkner, Electrochemical Methods: Fundamentals and Applications, 2000, 2 ed. , Wiley). For measurements, the working electrode holder comprising single unit of working material and thus a single contact surface with the electrolyte solution are used (Kissinger, Peter; William R. Heineman, Laboratory Techniques in Electroanalytical Chemistry, Second Edition, 1996, 2 ed., CRC).
The working electrode described above is most commonly used for electrochemical measurements directly on the unmodified electrode surface or on the surface additionally coated with the modifier layer. In both cases, the electrode requires a surface preparation process. For solid disc electrodes, in addition to electrochemical cleaning or sonication, the process involves mechanical polishing using an aluminium oxide suspension or other suitable abrasive material with an appropriate particle gradation. The electrode thus prepared can be used for measurements or further modified, e. g. by applying a modifier suspension e. g. nanoparticles, then the electrode surface is left to evaporate the solvent from the suspension and an electrode with the modifier layer is obtained.
The essence of the invention is a multiple disc electrode holder, characterized in that it consists of a cylindrical housing made of chemically and electrically resistant material having a through hole in the shape adapted to a conductive electrode carrier made of metal or alloy, most preferably brass. The conductive electrode carrier itself is a double-tapered cylinder, rolled out so that its narrowest end is an electrical contact connecting the conductive electrode carrier to the potentiostat / electrical circuit, and then passing on to a wider central portion of the cylinder. The second widest end of the conductive electrode carrier provides electrical contact with a working material discs, while still remaining within the cylindrical housing. At the bottom portion of the cylindrical housing there is a finely fitted disc made of chemically and electrically resistant material with through holes that contacts the widest portion of the conductive electrode carrier and reduces its contact with the working material discs only through the openings present. The working material discs are placed in these openings. The diameter of the openings in the disc corresponds to the size of the working materials discs. The electrode holder is drilled in such a way as to ensure perfect integration with the components of the electrode carrier and the disc.
According to invention, the working material discs are made of pyrolytic graphite or gold or platinum or silver.
In another embodiment of the invention, the working material discs are made of glassy carbon or boron doped diamond.
The main advantage of the multiple disc electrode holder according to the invention is that it allows to obtain statistically averaged results by means of a single measurement. Due to the use of the multiplied surface of the working electrode discs, called also n disc surfaces, it is possible to obtain n series of measurements results during a single recording, provided that n disc surfaces are used in the proposed holder. This allows for more consistent and repeatable results with less measurement error. Also, use of the multiple disc electrode holder according to the invention allows to reduce consumption of reagents and consumables, electricity and time upon measurement.
An additional advantage of the invention is the possibility of performing simultaneous working electrode discs surface cleaning, which refresh the surface of the working electrode and additionally prevents the occurrence of individual accidental errors that determine the quality of the performed electrochemical measurements. The invention is an alternative proposal, environmentally friendly in its application, to carry out multiplied measurements, particularly important during optimization or validation studies.
The invention was illustrated at the example and drawings, wherein:
is a schematic view of the multiple disc electrode holder with 3 working electrode disc, for n=3;
is an cross-sectional view of the cylindrical housing with 3 working electrode disc, for n=3;
is an bottom view of the multiple disc electrode holder with 3 working electrode disc, for n=3.

EXAMPLE

The multiple disc electrode holder consists of a cylindrical housing 1 which is made of chemically and electrically resistant material and comprises the electrically-conductive element in the form of double-tapered cylinder 2. The cylinder 2 is rolled out so that its narrowest end is the electrical contact 2a, connecting the holder to the potentiostat/electrical circuit. The cylinder 2 then passes into a wider central portion which is the conductive electrode carrier 2b inside the housing 1. The second, widest end of the cylinder 2 is the conductive electrode carrier 2c, located on the underside of the housing 1, provides electrical contact with the three working material discs 4, n =3 which are inserted in the inside body 3 made of chemically and electrically resistant material. The diameter of the holes in the inside body 3 corresponds to the dimensions of the working material discs 4, and the housing 1 is drilled in such a way as to ensure that the individual components of the electrode carrier 2a, 2b, 2c and the inside body 3 fit perfectly therewith, so the electrode holder ensures perfect integration with the components of the electrode carrier 2b and the working material discs 4 The working material discs 4 are made of glassy carbon, while housing 1 and inside body 3 are made of polyether ether ketone.
When connected to the electrical circuit and the potentiostat and placed the tested sample in supporting electrolyte solution, the measurement is carried out simultaneously on working surfaces of all three working material discs 4. Between electrochemical measurements, the surfaces of the working material discs 4 are refreshed simultaneously by mechanical polishing. As a result of individual differences in the structure of the electrically conductive materials, each of the working surfaces of the working material discs 4 acts as a separate sensors without being affected by the electrolytic processes occurring on the surfaces of the other working material discs 4. The result of the measurement is obtained as a total current representing the sum of the current flowing independently through each working material discs 4 or otherwise obtained in successive series of measurements. The recorded total current is subsequently divided by the number of working material discs 4 used, here in example and figures three, and the averaged value is given that could be understood otherwise as an average current recorded during successive series of measurements.

Claims

A multiple disc electrode holder comprising
a cylindrical housing (1) made of chemically and electrically resistant material and having a through hole in the shape adapted to a conductive electrode carrier (2b) in the form of a double-tapered cylinder (2) made of electrically conductive metal or alloy, which is rolled out so that the narrowest end of the conductive electrode carrier (2b) is an electrical contact (2a) connecting the conductive electrode carrier (2b) to the potentiostat/electrical circuit, and then the conductive electrode carrier (2b) passes into a wider central portion of a cylinder (2), the second widest end of the conductive electrode carrier (2b) located at the bottom portion of the cylindrical housing (1) has n openings for n working material discs (4) which are disposed in these openings, wherein working material discs (4) are placed at an inside body (3) having n through holes dimensioned to a diameter of n working material discs (4), wherein the inside body (3) is made from chemically and electrically resistant material.
The multiple disc electrode holder according to claim 1, wherein the conductive electrode carrier (2b) is made of brass.
The multiple disc electrode holder according to claim 1, wherein the working material discs (4) are made of pyrolytic graphite or gold or platinum or silver or glassy carbon or boron doped diamond.