I have a three-electrode cell setup for photocatalytic hydrogen production by water splitting. FTO coated with organic photocatalyst as WE, Pt wire as CE and Ag/AgCl as RE. In my Chronoamperommetry figure, I have so many fluctuations. I want to know whether I can use cyclic voltammetry to say may photocatalyst is safe or it has been degraded.
A simple of way of checking photo-activity is to interrupt the light during the potentiostatic test. If the current drops upon light interruption (dark condition) and gets back to its previous value when illuminated, then your material is 'still' photo active. Decrease in the photo current with time at a constant potential indicates performance degradation - not necessarily material degradation. You do not have to use CV to check stability, but it doesn't hurt using CV for generating additional data.
I agree with dr. Krishnan Raja .... because the dark reaction will cut the electric current which produced via irradiation as e (-) -h (+) pairs..... so no reaction in dark reaction.....
If you want to check the photo-corrosion of your photocatalyst by the voltammetry method, the best manner is performing chronoamperometry analysis (transient photocurrent vs. time). After several on-off cycles, if your result was as same as the I-t result of the intact photocatalyst, so your photocatalyst is flawless.
Meanwhile, I suggest that you perform the photoluminescence analysis. In this regard, if you witness an increase in PL intensity as compared to the spectrum of intact photocatalyst, this implies the lower photoinduced charge separation and the decline in photocatalytic activity as well. Hence, your photocatalyst has been disabled.
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