While observing overall water splitting of pure water, my heterostructure photocatalyst exhibited H2 evolution initially in 1st hour and then O2 evolution in 2nd and 3rd hour. After that it became inactive. I have used Pt and Ag as cocatalysts.
What can be the possible reason for;
(1). Why it is not able to produce H2 and O2 simultaneously?
(2). Why after 3rd hour, O2 evolution is also stopped?
Dear Muhammad Shuaib Khan
Based on my research experiences, I think that it was related to the stability of your heterostructure photocatalyst. When it was irradiated under the light, it may lead to the material destruction. Some material like Ag3PO4 photocatalyst showed the same under visible light within minutes (ex: photocatalysis examination). So, I suggests to analyze the stability of your photocatalyst. Hopely, it help you.
F. Febiyanto Yeah. The stability is an important parameter to consider here. Apparently, there was no change in color. However, the materials dispersion was quite low after one hour of irradiation. In case of Ag3PO4, how did you checked the stability? In your case, did you observe any appear-able changes after irradiation.
In my case, one possible consideration can also be the dissociation of heterostructure.
In my reports, the yellow powders of Ag3PO4 looks a brown and then become black color if we used it under the light continueously. Herein, the photocatalyst was deactivated or shows the low-catalysis reaction for the next examination. Simply, we checked using XRD which sometime some new peak appeared or its intensity was reduced. The new peaks come from Ag ions transformation to be Ag(0), AgO or Ag2O. Meanwhile, the reduced intensity was Ag ions release into solution so that the structure destruction happended.
Dear F. Febiyanto Indeed XRD is most suitable approach to detect any compositional change after light irradiation. My material is 2D-2D, a potential morphology change can also effect the activity. I ll check my sample with SEM as well.
Anyhow, thanks for your comments.
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