Chemistry Reference
In-Depth Information
6.
717
At higher pH values a smaller slope is observed possibly due to the potential drop
across an oxide layer of increasing thickness. No specific effect of the various anions
was observed. For
n-
Si in solutions, OCP increases with pH
with a slope of about 45 mV/decade from pH 4 to 13 which is similar to the pH depen-
dence of the flatband potential.
904
This indicates that the band bending of the electrode
is essentially constant at different pH values.
In solutions, according to Turner,
111
when HF is the rate-determining
reactant, OCP shifts in the negative direction with increasing HF concentration;
when
is the controlling factor, OCP becomes more positive with increasing
