Electrochemistry: Potentiostat, Galvanostat, EIS, FC test station

 


Electrodes - Working, Reference & Counter


Table of content for this page

Working electrode and accessories

Introduction

Our electrodes used for electrochemical measurements such as CV, LSV , DPV and so on are compact and easy enough to be polished by yourself.

Remove the cap covering the electrode, and check its surface prior to the first use. Carbon paste electrode is available in the form of carbon paste which user packs into a shallow well in the electrode holder supplied by us. Other electrodes are polished to immediate use. These electrodes are encapsulated in PEEK* - solid, well inert against solvent. Table of material inertness to solvents is shown below. However, long-term immersion in tetrahydrofuran or using under higher temperature which exceeds the temperature coefficient between plastic and electrode material might be a cause of crack. O-ring enables a position of an electrode to be adjusted in the voltammetry cell.

Potential Window of Pt, Hg, Carbon electrodes in aqueous solution

The figure below shows the appropriate materials of the electrodes to research at some potential range. To analyze the redox activity of a substance dissolved in a kind of aqueous electrolyte with certain pH, it is indispensable to consider about electrode's hydrogen over, oxygen over voltage and dissolution potential.

Working electrode selection

 
Choice of working electrode is a vital component for experiment
Redox potential of molecule under research have to fall in the potential window over which the background current due to the electrode itself must not disturb the experiment.

Pt (Platinum) and Au (Gold) electrodes - applied to organic or inorganic substances measurement because they have high overpotential for oxygen evolution and low overpotential for hydrogen evolution.

Hg (Mercury) electrode - well suited to measure reduction of metal ions because of its high overpotential for hydrogen evolution. Hg electrode can easily observe the reduction of Zn.

At the measurement with non-aqueous solvent, hydrogen/oxygen overpotential does not affect. Instead of that, decomposition potential of the non-aqueous solvent and supporting electrolyte comes to an important factor. Furthermore, impurity of water in non-aqueous solvent makes the potential window narrower depending on the quantity of the water.

Advantages of using Microelectrodes for CV measurement

  1. Little distortion from dissipation in potential or electrification flow
  2. Combination of PC enables to process at high sweep rate
  3. Analyzable short-lived intermediate in electrode reaction
  4. Mearsurable without support electrolyte
  5. Excellent measuring accuracy because of little influence of noise arising from electrification flow
  6. Smooth diffusion enough to obtain stationary state
Figure in right : the result of detection of a chemical product in subsequent reaction. By the faster sweep at 104 V/S, the peak (which is shown when the short-lived intermediate is reduced into the former substance) can be observed before the intermediate vanishes.

Variety, Features and Shapes of Working electrodes

Variety of Working Electrodes Features and Applications
Platinum electrode
(PTE)
Conventional electrode, which has hydrogen adsorptive wave, used for H2O2 and oxides detection
Gold electrode
(AUE)
Conventional electrode, which has no hydrogen adsorption wave, used for thiols detection
Glassy carbon electrode
(GCE)
Chemically stable electrode despite its relatively large over-potentials of oxygen and hydrogen evolutions
Silver electrode
(AGE)
For cyanide and sulfide detection
Carbon paste electrode
(CPE)
Mixed with enzyme etc. to make modified electrodes
Nickel electrode
(NIE)
Chemically modified to detect amino acids
Palladium electrode
(PDE)
Used to study the process of adsorption and desorption of hydrogen
Plastic formed carbon electrode
(PFCE)
Its highly-oriented graphite edge is exposed to the surface with cost effective, similar feature of HOPG

List of available working electrodes and accessories

Gauze Electrode

Catalog No. Description Isolation Mesh
size
Electrode
size
A-002250 Platinum gauze electrode PEEK 80 mesh 25 x 35 mm
A-002251 Gold gauze electrode PEEK 100 mesh 25 x 35 mm

Glassy Carbon Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002417 GCE Glassy Carbon electrode PEEK 10 mm 5 mm
A-002012 GCE Glassy carbon electrode PEEK 6 mm 3 mm
A-012297 GCE Glassy carbon electrode PEEK 6 mm 1.6 mm
A-002411 GCE Glassy carbon electrode PEEK 6 mm 1 mm
A-012298 GCE Glassy carbon electrode PEEK 3 mm 1.6 mm
A-002412 SGCE Glassy Carbon electrode PEEK 3 mm 1 mm
A-002002 MCE Micro Carbon fiber electrode Glass 4 mm 33 µm
A-002007 MCE Micro Carbon fiber electrode Glass 4 mm 7 µm

Gold Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002418 AUE Gold electrode PEEK 10 mm 5 mm
A-002421 AUE Gold electrode PEEK 6 mm 3 mm
A-002014 AUE Gold electrode PEEK 6 mm 1.6 mm
A-002314 SAUE Gold electrode PEEK 3 mm 1.6 mm
A-002010 MAUE Micro gold electrode Glass 4 mm 100 µm
A-002004 MAUE Micro gold electrode Glass 4 mm 25 µm
A-002006 MAUE Micro gold electrode Glass 4 mm 10 µm

Platinum Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002420 PTE Platinum electrode PEEK 10 mm 5 mm
A-002422 PTE Platinum electrode PEEK 6 mm 3 mm
A-002013 PTE Platinum electrode PEEK 6 mm 1.6 mm
A-002313 SPTE platinum electrode PEEK 3 mm 1.6 mm
A-002009 MPTE Micro Platinum electrode Glass 4 mm 100 µm
A-002003 MPTE Micro Platinum electrode Glass 4 mm 25 µm
A-002015 MPTE Micro platinum electrode Glass 4 mm 15 µm
A-002005 MPTE Micro Platinum electrode Glass 4 mm 10 µm

Silver Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002416 AGE Silver electrode PEEK 10 mm 5 mm
A-002419 AGE Silver electrode PEEK 6 mm 3 mm
A-002011 AGE Silver electrode PEEK 6 mm 1.6 mm
A-002315 SAGE Silver electrode PEEK 3 mm 1.6 mm

Nickel Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002016 NIE Nickel electrode PEEK 6 mm 1.5 mm
A-002273 MNIE Micro Nickel electrode Glass 4 mm 100 µm

Graphite Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002252 Pyrolytic Graphite Electrode (Basal Plane) PEEK 6 mm 3 mm
A-002253 Pyrolytic Graphite Electrode (Edge Plane) PEEK 6 mm 3 mm
A-002408 PFCE 3 Carbon electrode PEEK 6 mm 3 mm
A-002409 PFCE 1 Carbon electrode PEEK 6 mm 1 mm
A-011854 SPFCE Carbon electrode PEEK 3 mm 1 mm

Palladium Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002019 PDE Palladium electrode PEEK 6 mm 1.6 mm
A-002319 SPDE Palladium electrode PEEK 3 mm 1.6 mm

Iron Electrode and Copper Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002018 FEE Iron electrode PEEK 6 mm 1.5 mm
A-002017 CUE Copper electrode PEEK 6 mm 1.6 mm
A-002271 MCUE Micro copper electrode Glass 4 mm 25 µm

Carbon Electrode

Catalog No. Description Isolation Outside diameter Inside diameter
A-002210 CPE Carbon paste electrode PEEK 6 mm 3 mm
A-002223 SCPE carbon paste electrode PEEK 3 mm 1.6 mm

All electrodes are developped for utilization at normal temperature and pressure.


Counter electrodes

Please select suitable Counter electrode according to your application and budget.

Catalog No. Description
A-002222 Pt Counter Electrode for VC-2
A-002233 Pt Counter Electrode for VC-3
A-002234 Pt Counter Electrode (coiled)

Reference electrodes

Reference electrodes are widely used as for electrochemical measurements (CV, LSV, DPV, etc.) and electrochemical devices (electrochemical detectors for HPLC, electrochemical biosensor, etc... Various kinds such as aqueous, nonaqueous, calomel and own-constructing types are available.

Warning: Vycor glass diameter was changed from 3.2 mm to 2.85 mm.

Catalog No. Description Length (mm) OD (mm) Liquid Conjunction Tip Configuration of Electrode
Ag/AgCl type
A-012167 RE-1B Silver - silver chloride reference electrode 70 6 Vycor glass Ag/AgCl/NaCl
A-012168 RE-1S Silver - silver chloride reference electrode 40 4.5 Vycor glass Ag/AgCl/NaCl
A-012169 RE-3V Silver - silver chloride reference electrode 48 10 Vycor glass Ag/AgCl/NaCl
Ag/Ag+ type
A-012171 RE-7 Non Aqueous reference electrode 70 6 Vycor glass Ag/Ag+/ACN/TBAP
A-012172 RE-7S Non Aqueous reference electrode 40 4.5 Vycor glass Ag/Ag+/ACN/TBAP
A-012173 RE-7V Non Aqueous reference electrode 48 10 Vycor glass Ag/Ag+/ACN/TBAP
A-012174 RE-7VP Non Aqueous reference electrode 48 10 Vycor glass Ag/Ag+/ACN/TBAP

 

Catalog No. Description Length (mm) OD(mm) Liquid Conjunction Tip Configuration of Electrode
Ag/AgCl type
A-002058 RE-1C Silver - silver chloride reference electrode 90 6 Ceramic Ag/AgCl/KCl
Calomel type
A-002056 RE-2B Calomel reference electrode 90 6 Ceramic Calomel
Hg type
A-002057 RE-2C reference electrode 90 6 Ceramic Hg/Hg2SO4
A-011503 RE-6H reference electrode Kit available in alkaline solution 90 6 Ceramic Hg/HgO/1 M NaOH

Applications

RE-1B - Ag/Cl Reference electrode for CV
RE-1S - Ag/Cl Reference electrode for SECM
RE-1C - Ag/Cl Saturated KCl Reference electrode
RE-3V - Ag/Cl Reference electrode applied to Flow cell
RE-7 - Ag/Ag+ Reference electrode for CV of Non-Aqueous solvent
RE-7S - Ag/Ag+ Reference electrode for SECM
RE-7V - Ag/Ag+ Reference electrode applied to Flow cell
RE-2B - Available as a standard electrode of reference electrodes
RE-2C - Reference electrode free from chloride ion
RE-6H - Reference electrode kit available in alkaline solution

 

Reference Electrode potentials at 25 °C

NHE(Normal Hydrogen Electrode) 0mV
SCE(Saturated Calomel Electrode) 241mV
SSCE(Sodium Saturated Calomel Electrode) 236mV
Ag/AgCl(Saturated KCl) 199mV
Hg/Hg2SO4(Saturated K2SO4) 640mV

RE-2C Reference Electrode [Catalog No. A-010385]

Developed for the sake of eliminating any influence of chloride ion from measurements. Consists of mercury, mercury sulfate and saturated potassium sulfate solution.

Hg2SO4 + 2e = 2Hg + SO42- E0 = 650 mV vs NHE (25°C)

A-002056 RE-2B Calomel Reference electrode A-002058 RE-1C Silver - silver chloride reference electrode
Hg2Cl2 + 2e = 2Hg +2Cl-
E0 = 241 mV vs NHE (25 °C)
AgCl + e = Ag+ + Cl-
E0 = 199 mV vs NHE (25 °C)
RE-2B Calomel Reference electrode and RE-1C Silver - silver chloride reference electrode have the same shape as RE-2C.

Supporting Electrolyte

Supporting electrolyte is indispensable in electrochemistry. Following terms should be taken into account to choose adequate one for your application:

  1. Soluble enough in solvent
  2. The potential window is wide
  3. No reaction with solvent and sample

Common Support Electrolyte using for organic solvent:

  • TMAP: Tetramethylammonium perchlorate
  • TBAF: Tetrabutylammonium fluorophosphate
  • etc.

In addition to our range of electrodes, big size electrodes are available for use with large cell vials (80 mL and more).

Metal working electrodes - king size

Bio-Logic proposes metal electrodes to be used as working electrodes in an electrochemical cell. Most of these electrodes are platinum based.

Drawing
No.
Catalog No. Description
1 R-XM110 Platinum electrode wire 1 mm diam (for voltammetry)
Length: 80 mm; OD: 8 mm
2 R-XM120 Platinum electrode plate 5 mm by 5 mm (for voltammetry)
Length: 120 mm; OD: 8 mm
3 R-XM140 Platinum electrode plate 8 mm by 8 mm (for voltammetry)
Length: 80 mm; OD: 8 mm
4 R-XM150 Platinum electrode disk 10 mm diam (for voltammetry)
Length: 120 mm; OD: 12 mm
5 R-M291C Glassy Carbon electrode rod 3 mm diam (for voltammetry)
Length: 103 mm; OD: 8 mm

Metal working electrodes are provided with a screw head. The connection cable and optional conical rings are sold separately. Please select in the following list:

Catalog No. Description
R-A94L111 Short connection cable for Screw cap Electrode
Length: 10 cm with 2 mm banana plug
R-CL111 Long connection cable for Screw cap Electrode
Length: 1 m with 4 mm banana plug
R- X31M012 12 mm OD conical rings for 8 mm OD electrodes (4 pieces)

Reference electrodes - king size

Drawing
No.
Catalog No. Description

Use

1 R-XR300 Ag/AgCl reference electrode Sat KCl
Length: 120 mm; OD: 8 mm
CV
2 R-XR820 Ag/AgCl reference electrode
Length: 160 mm; OD: 8 mm
EIS
3 R-REF921 Calomel Reference electrode non aqueous (LiCl)
Length: 103 mm; OD: 7,5 mm
General purpose
4 R-XR110 Calomel Reference electrode in KCl sat
Length: 80 mm; OD: 8 mm
CV
5 R-REF621 Hg/HgSO4 reference electrode in sat K2SO4
Length: 103 mm; 8 mm
Chloride free
6 R-XR200 Hg/HgSO4 reference electrode in sat K2SO4
Length: 120 mm; OD: 8 mm
CV
7 R- XR400 Hg/HgO reference electrode in 0,1M KOH
Length: 120 mm; OD 8 mm
CV

Reference electrodes are provided with a screw head. The connection cable and optional conical rings are sold separately. Please select in the following list:

Catalog No. Description
R-A94L111 Short connection cable for Screw cap Electrode
Length: 10 cm with 2 mm banana plug
R-CL111 Long connection cable for Screw cap Electrode
Length: 1 m with 4 mm banana plug
R- X31M012 12 mm OD conical rings for 8 mm OD electrodes (4 pieces)

Salt bridge junctions for reference electrodes

Drawing
No.
Catalog No. Description
1 R-AL100 Salt bridge junction ceramic
Length: 70 mm; OD: 12 mm
2 R-AL110 Salt bridge junction ceramic
Length: 250 mm; OD: 8 mm
3 R-AL210 Salt bridge junction ceramic with reverse sleeve (non aqueous)
Length: 138 mm; OD: 8 mm
4 R-AL120 Salt bridge junction ceramic
Length: 138 mm; OD: 8 mm
 

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