Choose between PTFE and PEEK electrode bodies for glassy carbon, platinum, gold and silver disc working electrodes in electrochemistry

By the End of This Guide, You Will Understand

By the end of this guide, you should be able to:

• choose between PTFE and PEEK body materials more confidently;
• understand why PEEK is often preferred for routine reusable disc electrodes;
• understand why PTFE may be better for aggressive chemical environments;
• recognise how polishing can change the geometry of a disc electrode;
• explain why glassy carbon in PEEK may appear slightly raised after repeated polishing;
• select a suitable body material for glassy carbon, platinum, gold and silver disc electrodes.

ScienceGears Technical Team Insight

“The electrode body is not just passive plastic. It controls sealing, polishing behaviour, geometry stability and long-term reproducibility. Choosing PTFE or PEEK correctly can prevent many avoidable problems in electrochemical measurements.” — ScienceGears Technical Team

1 Introduction

When choosing a working electrode for electrochemistry, most researchers first think about the active electrode material. Should it be glassy carbon? Platinum? Gold? Silver? Boron-doped diamond? Nickel? Copper?

That is important, but it is only one part of the electrode design.

For reusable disc working electrodes, the conductive disc is normally embedded inside an insulating body material. Two of the most common body materials are PTFE and PEEK. Both are widely used in electrochemical laboratories, but they are not interchangeable in every situation.

The body material can influence: chemical compatibility; mechanical durability; polishing behaviour; sealing around the disc; long-term dimensional stability; electrode lifetime; surface geometry; and reproducibility of electrochemical data.

This becomes especially important when the electrode is repeatedly polished with alumina or diamond slurry, rinsed, briefly sonicated and reused for cyclic voltammetry, electrocatalysis, corrosion, sensors, battery-material studies, fuel-cell catalyst studies or other electrochemical measurements.

So the practical question is: Should you choose a PTFE body or a PEEK body for your electrochemistry experiment?

The answer depends on your electrolyte, electrode disc material, cleaning method and how often the electrode will be polished.

ScienceGears supplies reusable working electrodes, reference electrodes and counter electrodes for electrochemistry laboratories across Australia and New Zealand. Explore Working Electrodes →

2 Quick Answer: PTFE or PEEK?

For most routine reusable disc working electrodes: PEEK is the preferred default body material.

For chemically aggressive environments: PTFE may be preferred when maximum chemical inertness is more important than mechanical robustness.

A simple rule:

Both materials have a place in electrochemistry. The best choice depends on the experiment.

For help selecting glassy carbon, platinum, gold or silver disc electrodes, contact the ScienceGears technical team. Browse Electrodes and Accessories →

PTFE and PEEK are both used as insulating body materials for reusable working electrodes, but the best choice depends on chemistry, polishing frequency and the active disc material.

3 What Is PTFE?

PTFE stands for polytetrafluoroethylene.

It is well known for: 

• Excellent chemical resistance;
• Low friction;
• Low surface energy;
• Good electrical insulation;
• Strong resistance to many aggressive chemicals.

In electrochemistry, PTFE can be useful when the electrolyte, cleaning solution or chemical environment is very aggressive. It is also used in many electrochemical cells, electrode holders, seals and chemically resistant components.

However, PTFE is relatively soft compared with many engineering plastics and electrode materials. During repeated polishing, PTFE can wear, deform or round more easily than harder materials.

This means PTFE can be very good chemically, but it may not always be the best choice mechanically.

4 What Is PEEK?

PEEK stands for polyether ether ketone.

It is a high-performance engineering polymer known for:

• Good mechanical strength;
• Good dimensional stability;
• Good chemical resistance in many electrolyte environments;
• Better rigidity than PTFE;
• Good machinability for precision electrode bodies;
• Suitability for reusable laboratory components.

PEEK is commonly used for reusable disc working electrodes because it offers a strong balance between mechanical durability and chemical resistance.

However, PEEK is still a polymer. It is harder and stronger than PTFE, but it is much softer than very hard electrode materials such as glassy carbon or boron-doped diamond.

5 Why the Electrode Body Material Matters

A reusable disc working electrode is a small precision assembly.

It normally contains:

• The conductive disc material;
• The insulating body material;
• Internal electrical contact;
• Sealing around the disc;
• A polished exposed surface.

For ideal inlaid-disc electrochemical behaviour, the disc should be flat, clean, well-defined and flush with the surrounding body.

If the disc becomes recessed below the body, or protrudes slightly above it, the electrode may still work, but its behaviour may no longer match the ideal disc-electrode geometry.

This can affect:

• Diffusion field shape;
• Limiting current;
• Current density;
• Catalyst loading uniformity;
• Surface modification reproducibility;
• RDE/RRDE measurements;
• Analytical sensor response;
• Comparison between experiments;

For routine cyclic voltammetry with a 2 mm or 3 mm disc electrode, a very small height mismatch may not necessarily invalidate the measurement, but it should still be monitored and recorded. However, for high-precision measurements, geometry becomes more important.

The ideal disc electrode is flat and flush with the surrounding insulating body. Recessed or protruding geometries can change the electrochemical response, especially in mass-transport-sensitive experiments.

The ideal disc electrode is flat and flush with the surrounding insulating body. Recessed or protruding geometries can change the electrochemical response, especially in mass-transport-sensitive experiments.

For complete electrochemical setups, ScienceGears can support potentiostats, cells, electrodes and accessories matched to your experiment. View Electrochemistry Instrumentation →

6 PEEK vs PTFE: Practical Comparison

In most routine electrochemical laboratories, PEEK is preferred when the electrode will be polished and reused many times. However, PTFE is still very valuable when chemical resistance is the main concern.

7 Why Polishing Changes the Discussion

Many reusable disc electrodes are polished before use.

A typical workflow may include: 

• polishing with alumina or diamond slurry;
• rinsing with ultrapure water;
• short sonication to remove trapped polishing particles;
• final rinsing;
• electrochemical testing.

This process can refresh the electrode surface and improve reproducibility. However, polishing is also a mechanical abrasion process. That means it does not only affect the conductive disc. It can also affect the surrounding PTFE or PEEK body.

Over time, repeated polishing can slowly change the surface profile of the electrode. The disc and body may not wear at the same rate. This is where hardness mismatch becomes important.

8 Hardness Mismatch: A Practical but Often Overlooked Issue

The conductive disc and the insulating body material can have very different hardness and wear behaviour. If the disc is much harder than the body, the body may wear faster during polishing. The disc can then appear slightly raised. If the disc is softer than the body, the disc may wear, scratch, smear or become slightly recessed, depending on the material and polishing method.

9 Why Glassy Carbon in PEEK Can Appear Slightly Raised

Glassy carbon is widely used because it has a broad potential window, low background current, good chemical stability and useful electrochemical behaviour for many applications. However, glassy carbon is also much harder than PEEK.

During repeated polishing, especially if the user applies heavy pressure or uses coarse abrasive frequently, the surrounding PEEK body can wear slightly faster than the glassy carbon disc. When this happens, the glassy carbon disc may appear to sit slightly above the PEEK body.

This does not necessarily mean that the glassy carbon has moved outward. More likely, the PEEK around it has been polished down slightly faster.

For glassy carbon electrodes, PEEK is still usually preferred over PTFE because PTFE is even softer and more prone to deformation or wear.

10 Why Gold Electrodes Can Behave Differently

Gold behaves very differently from glassy carbon. Glassy carbon is hard and brittle. Gold is soft and ductile.

During polishing, gold can: 

• Scratch;
• Smear;
• Burnish;
• Change roughness;
• Polish along with the surrounding surface.

This may be one reason why a gold disc in a PEEK body can sometimes appear visually flatter than a glassy carbon disc in a PEEK body after repeated polishing.

However, this does not mean gold is immune to polishing damage. Gold surfaces can be very sensitive, especially in:

• Self-assembled monolayer studies;
• Thiol chemistry;
• Biosensors;
• Surface modification;
• Trace analysis;
• Oxide stripping;
• Adsorption studies.

For gold electrodes, the key is gentle, consistent surface preparation.

11 What About Platinum Electrodes?

Platinum is widely used in electrochemistry because of its conductivity, catalytic activity and stability in many aqueous systems.

For platinum disc electrodes used in PEEK-compatible electrolytes, PEEK is generally a very good default body material because it provides:

• Good mechanical stability;
• Good polishing durability;
• Good dimensional stability;
• Good suitability for repeated use.

However, platinum surface chemistry can be complex. Platinum can form oxides, adsorb species and show strong catalytic behaviour. Depending on the experiment, polishing may be combined with electrochemical cleaning or potential cycling.

Platinum Electrode Recommendation

12 What About Silver Electrodes?

Silver electrodes require more care because silver can form oxides, chlorides, sulfides and other surface films depending on the electrolyte.

PEEK is suitable for many silver disc electrodes, especially when the electrode will be polished and reused. However, PTFE may be preferred if chemical compatibility is the main concern.

13 Recommended Body Material by Electrode Type

14 Application-Based Selection Guide

15 When Should You Choose PEEK?

Choose a PEEK body when:

• the electrode will be polished regularly
• the electrode will be reused many times
• dimensional stability is important
• mechanical durability is important
• the electrode will be used in routine aqueous electrochemistry
• the electrode will be used in teaching labs
• the electrode disc is glassy carbon, platinum, gold, silver or BDD and the electrolyte/cleaning protocol is compatible with PEEK
• the work involves RDE/RRDE or reproducibility-sensitive measurements
• you want a premium reusable electrode body

For most routine reusable disc working-electrode applications in Australian and New Zealand laboratories, PEEK is usually the better default choice, provided the electrolyte and cleaning protocol are compatible with PEEK.

16 When Should You Choose PTFE?

Choose a PTFE body when:

• the electrolyte is highly aggressive
• maximum chemical inertness is required
• the cleaning chemistry is not suitable for PEEK
• the experiment involves aggressive media or cleaning chemistry where PEEK compatibility is uncertain
• the electrode will not be polished heavily or frequently
• lower cost is a priority
• the body material must have very low surface energy

PTFE is an excellent chemical-resistance material, but it is mechanically softer than PEEK.

17 Best-Practice Checklist for Polishing PTFE and PEEK Body Electrodes

Use this checklist for routine reusable disc working electrodes:

Polishing can improve surface cleanliness, but aggressive polishing can also change the disc/body geometry. Use light pressure and a consistent method

ScienceGears can help laboratories select suitable electrode polishing supplies and cleaning workflows. Shop Electrode Polishing Accessories →

18 Common Mistakes Researchers Make

1. Choosing the Body Material Only Based on Price

PTFE may be cheaper, but PEEK may last longer for frequently polished electrodes. For reusable working electrodes, the lowest initial price may not always give the best long-term value.

2. Assuming PEEK Cannot Wear

PEEK is mechanically stronger than PTFE, but it can still wear during repeated polishing. This is especially noticeable when the disc material is much harder than PEEK, such as glassy carbon.

3. Over-Polishing Glassy Carbon Electrodes

Glassy carbon is hard, but aggressive polishing can still change the surrounding body geometry and shorten electrode life.

4. Treating Gold Like Glassy Carbon

Gold is soft and ductile. It should not be polished with the same aggressive approach used to restore heavily fouled glassy carbon.

5. Ignoring Sonication Time

Short sonication can help remove alumina particles. Prolonged or aggressive sonication may not be suitable for all electrode assemblies.

6. Not Inspecting the Electrode Surface

A quick visual or microscopic inspection can reveal scratches, gaps, protrusion, recession or polishing damage before it affects the data.

7. Not Standardising the Cleaning Protocol

If polishing varies from user to user, the electrochemical response can vary too. This is especially important in shared labs and teaching laboratories.

19 Does a Slightly Raised or Recessed Disc Matter?

It depends on the experiment. For routine cyclic voltammetry with a 2 mm or 3 mm disc electrode, a very small height mismatch may not be a major issue.

However, it can become important for :

• rotating disc electrode measurements;
• rotating ring-disc electrode measurements;
• ORR, HER, OER and CO₂ reduction studies;
• catalyst benchmarking;
• diffusion-controlled limiting-current studies;
• electrochemical sensors;
• microelectrode experiments;
• catalyst ink deposition;
• current-density comparison;
• publication-quality reproducibility.

 For these applications, a flat, flush and reproducible surface is strongly preferred.

For rotating disc and rotating ring-disc measurements, electrode geometry and polishing consistency become especially important. See RDE/RRDE Systems →

20 Practical Decision Tree

21 Frequently Asked Questions

22 Final Recommendation

For most reusable disc working electrodes used in electrochemical experiments: PEEK is the preferred default body material. It typically provides better mechanical strength, dimensional stability and polishing durability than PTFE.

However: PTFE is preferred when maximum chemical inertness is the highest priority.

For glassy carbon electrodes, PEEK is still the recommended default, but users should understand that glassy carbon is much harder than PEEK. Repeated aggressive polishing can gradually make the glassy carbon disc appear slightly raised relative to the body.

For gold and silver electrodes, the issue is different. These metals are softer and more ductile, so polishing should be gentle to avoid scratching, smearing or changing the active surface.

The best electrode choice depends on matching: 

• The active disc material;
• The body material;
• The electrolyte;
• The polishing method;
• The cleaning protocol;
• The reproducibility requirement.

A well-selected and well-maintained working electrode gives cleaner, more reproducible and more meaningful electrochemical data.

23 How ScienceGears Can Help

ScienceGears supports researchers across Australia and New Zealand with electrochemical instruments, working electrodes, reference electrodes, counter electrodes, electrochemical cells and custom electrochemical solutions.

Whether you are working with glassy carbon, platinum, gold, silver, boron-doped diamond or custom electrode materials, we can help you select a suitable electrode body material and polishing workflow for your application.

We support applications including:

• cyclic voltammetry;
• electrocatalysis;
• corrosion testing;
• electrochemical sensors;
• batteries and supercapacitors;
• fuel cells and electrolysers;
• RDE/RRDE measurements;
• in-situ spectroelectrochemistry;
• teaching laboratories;
• custom electrochemical cell development.