Space Grant Consortium - University of Wisconsin - Green Bay

minutes and the negative platinum electrode became coated with a layer of platinum
black. To increase the adherence of the platinum black the process was performed in a
sonicator. In studies done by Marrese (1987) this removed loose particles and kept the
strongly adhered particles. Alternation of the polarity on the electrodes was also
performed in some tests to platinize two electrodes at the same time similar to the work
done in MacNevin and Levitysky (1987.
Figure 2: (Left) On the bottom is the power supply used to supply the system with two
volts, and on top is the waveform generator used to alternate the polarity of the
electrodes. (Right) Platinum electrodes in the platinization solution.
A current profile of each of the electrodes was found by using cyclic voltammetry
on the voltage range of -.2 volts to 1.2 volts. This range was chosen so that the current
profiles could be compared to previous studies performed on platinized electrodes in
Marrese (1987). The measurements obtained were current and voltage compared to a
silver/silver chloride reference electrode.
Results
Cyclic voltammetry data was recorded and plotted using a spreadsheet program.
This data was used to generate a current versus voltage plot. This was done for both
blackened and unblackened electrodes. The results for the unblackened electrode can be
seen in figure 3 and the results for the blackened electrode can be seen in figure 4. The
current for the unblackened electrode is in micro amps and the current for the blackened
electrode is in milliamps. This shows that the current produced by the blackened
electrode is up to one hundred times that greater than that of the unblackened electrode.
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