After about 2 days of ETC at 30V and 45-50ºC the cathode is completely black. I'm assuming this is platinum sulfide (correct?). Has anyone found a good way to clean the electrodes in-between runs? For that matter, does this tarnish affect the outcome of ETC? I have notice no issue with black particles depositing on my sample as long as I keep the voltage low (~30V or lower). However, I haven't been doing this very long.
So far, I have tried filling the chamber with 70% isopropanol and placing it in a ultrasonic bath for several hours. This mildly cleaned the electrodes. I also tried this silverware cleaning trick, but to no avail: http://scifun.chem.wisc.edu/homeexpts/tarnish.html