3mm glass carbon electrode, total length about 85mm, copper rod polished joint about 15mm, PTFE outer tube diameter about 6mm

glassy carbon electrode

Glassy carbon is abbreviated as glassy carbon. It is a process of slowly heating polyacrylonitrile resin or phenolic resin to a high temperature (up to 1800°C) in an inert atmosphere to form a glass-like amorphous carbon, which is suitable as an electronic conductor material for electrodes. It is also widely used in table tennis soleplates.

Glassy carbon electrode is the abbreviation of glassy carbon electrode.

The advantages of glassy carbon electrodes are good conductivity, high chemical stability, low thermal expansion coefficient, hard texture, good air tightness, and a wide range of potential applications (from about -1 to 1V, relative to saturated calomel electrodes), and can be manufactured In the shape of electrodes such as cylinders and discs, it can be used as a substrate to make mercury film glassy carbon electrodes and chemically modified electrodes. It has been widely used in electrochemical experiments or electroanalytical chemistry.

Electrode characteristics:

The glassy carbon electrode is one of the widely used working electrodes. It is a good inert electrode with good conductivity, high hardness, high smoothness, high hydrogen overpotential, wide polarization range, chemical stability, and can be used as an inert electrode. The electrode is directly used for anode dissolution, cathode and voltammetric determination of variable valence ions, and can also be used as a chemically modified electrode.

Electrode treatment and maintenance: (Note: Try to avoid ultrasonic cleaning. It is recommended to use a polishing powder polishing plate to clean the electrode residues)

It must be ensured that the glassy carbon surface is mirrored and clean. Because the surface of glass charcoal is easily contaminated by some organic metal compounds, which seriously affects the measurement (no peaks, miscellaneous peaks, and no recurrence), it must be cleaned before measurement. There are three main methods, chemical method

Soak and scrub with 3 moles of nitric acid.
Soak and scrub with ammonia water absolute ethanol or ethyl acetate 1:1.
It can also be scrubbed with alcohol and then soaked in 6NHCL or 4NHO3. Electrochemical treatment: that is, repeated polarization (reset-scan) (anode-cathode to cathode) in the voltage range of +0.8V-(-1.8V (0.5MKcLPH7 except O2I) voltage range (reset-scan) (anode-cathode to cathode) if there is serious pollution and pitting, The scratches can be treated mechanically. First, use 5000 mesh sandpaper to polish and smooth the electrode surface. After there are no scratches on the surface of the electrode, put 0.05um polishing powder on the deerskin or polishing flannel, dry rubbing and polishing, and then wipe it with a clean polishing cloth. Clean the surface of the electrode tip. Also available
Combine several methods according to the electrode situation. It is not advisable to soak the electrode in strong acid, strong alkali and organic solvent for a long time.

Because the glassy carbon electrode is an inert electrode, so when using the plating scanning material is the scanning electrode, such as mercury plating, copper, gold is mercury film, copper film, gold film electrode. For example: anodic stripping mercury plating and gold plating. There are two types of mercury plating on glassy carbon: the first is co-situ mercury plating, that is, adding a certain amount of Hg+ (usually mercury oxide and mercury nitrate) to the sample to be analyzed for electrolytic enrichment At the point of the ion, an amalgam is formed at the same time. After scanning and dissolution, the ion or mercury film to be measured is completely dissolved at a positive potential. The electrode can also be removed and the mercury film can be wiped clean with filter paper. Ensure that the electrode surface is still in the original state during the second analysis to ensure reproducibility. Generally, the concentration of mercury ions is 500-1000 times the concentration of the measured ions. The second type is the pre-mercury coating. Measure the long-term electro-accumulation of mercury under the ion electrolysis potential. For example, the mercury film can be produced by electrowinning at -0.2V for a long time when measuring cu, but to prevent the danger of electrowinning cu, pb, cd, zn, this method is inefficient and takes a long time. 2. Under the condition of on-site mercury plating, after electrowinning for a period of time, scan dissolution, dissolve again at the termination potential for normal time, dissolve the ions to be tested, and then enrich-dissolve, repeat several times to obtain a layer without waiting Mercury membrane for ion measurement.

For example, 0.5MKCL+2×10-2MHg+ dozens of drops of saturated NaSO3, stir at -1.4V for 5-10 minutes to enrich, scan to -0.1V in 15 seconds under stirring, and continue to stir and dissolve at -0.1V for 30 seconds , And then stir and enrich for 5-10 minutes in the reset state, stir and scan for 15 seconds to -0.1V, and then stir and dissolve at -0.1V for 30 seconds. After the solution is still, take out the electrode and rinse the electrode support rod with water to prevent the coating from breaking through. When plating mercury, be careful not to have bubbles under the electrode, otherwise the mercury plating layer will not be uniform and the electroplating will not be on. The electrode can be soaked in 1:1 nitric acid when it is not used for a short time. save. The basic essentials of glassy carbon gold plating are the same as those of mercury plating.