I am working on photoelectrochemical water splitting using CdS-NaNbO3 as a photo-anode. I have both the photocatalytic hydrogen generation data for the powder photocatalyst and the photocurrent data from the pelleted CdS-NaNbO3 photo anode.
How can I calculate the turn over number (TON) and faradaic efficiency for hydrogen evolution reaction?
- Very simple, measure the amount of H2 produced during a certian time period of electrolysis,
- Next, dertermine the moles of H2 that must be generated theoretically during that time, (by current time data)
-and than you can determine the faradaic efficiency by comparing these two.
for TON, you need the data for the chemical / catalytic species in the medium.
If usinf surface, you need to determine the surface active species and the H2 evolved per unit area/active species.
Thank you Dr. Joya. May I ask you how can I determine number of moles of H2 generated theoretically during a certain tie from current time data. I have amperometric data (I Vs T at ocp).Please help me...
With I vs T you can calculate coulombs of charge ( 1C = 1A x 1sec) by integrating your current over time. If you used a potentiostat maybe it can display your data in C automatically.
Convert coulombs to moles of electrons using the Faraday constant, then divide by two to get the theoretical moles of H2 (since 2 e- per 1 H2 molecule).
(But by 'ocp' do you mean Open Circuit Potential? That implies no current flow...)
If you are working with a photoanode, you are evolving oxygen. The hydrogen is evolve for instance in the counter electrode.
Calculate the turnover for HER would be, as defined by your system, wrong
Number of Hydrogen moles =(Current in amperes X Time in seconds)/(Unsigned numeric charge on the ion X Faraday)
I hope it may be useful.
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