Carbon dioxide electrode principle

The carbon dioxide electrode is a method for determining the carbon dioxide content in a sample by measuring the concentration of carbon dioxide. Its principle is based on the study of gas electrochemistry.

The CO2 electrode usually consists of a working electrode and a reference electrode. The working electrode is a silver/silver-silver chloride electrode wrapped in a thin film separated by a selective semipermeable membrane. When CO2 is above the semipermeable membrane, it reacts and produces an acid-base reaction with water molecules, which will cause the water molecules to decompose into hydrogen ions and carbonate ions. These ions pass through the semipermeable membrane into the working electrode and are converted into current. The magnitude of the current is proportional to the CO2 concentration.

The function of the reference electrode is to provide a stable potential to ensure the accuracy and repeatability of the working electrode measurement results. The reference electrode is usually a silver/silver-silver chloride electrode, and its potential is repeatable.

Carbon dioxide electrodes are widely used in environmental monitoring, industrial process control, medical diagnosis, food safety and other fields.