Why do polarization curves of sol-gel coated cu electrodes the current rises continuously with an increase in potential and what does this mean?
can you give more data on what is the potential range and what is the solution in which is used for polarization and also what is the substrate and coating thickness of Cu
Polarization was carried out in 3.5% NaCl solution with the potential range is -1.2 to +1.2 V/SCE. The coating thickness is 10.54 nm
In polarization curves of sol-gel coated cu electrodes in 3.5 % NaCl, the current rises continuously with increase in potential. What does it mean? Why?
When you apply potential current rises due to electrochemical reaction till O xygen evolves or on cathodic side Hydrogen evolves? it is simple E vs I relationship --
E=f( I,t) --
sweep rate ( voltage/ sec) is a function of current --
Dear Prof.
Thanks. In the above case the polarization studies were carried between -0.6 V to +0.2 V (SCE). Above +0.2 V also the current increases continuously. Whether it implies that the coating is not that much protective towards corrosion?
due to oxygen evolution -- it has nothing to do with the coating
Hi Viswes..
It consisting of (3-aminopropyltrimethoxysilane) APTMS and (tetramethylorthosilicate) TMOS.
if you look at the water stability areas .. like Prof. Muralidharan has mentioned.. the stability region is between -0.5 to 1 V, at neutral pH, if you have an acidic or basic solution then these limits shift..
it is clear that above 2 V what you see is current increase due to gas evolution..
also if your coating is not dense then you may find some contribution in the current from Cu dissolution.
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