Abstract
I2 effects on silver deposition current efficiency were investigated using a potassium iodide bath. Cathodic polarization curves in the I2 bath and Pt electrode rest potential in the aged KI solution were measured to clarify the I2 reduction mechanism.
The following results were obtained:
(1) In the lower pH range, I2 concentration in the bath increases with time in the presense of air according to equation (i):
4H++4I-+O2_??_2I2+2H2O……(i)
(2) Silver deposition current efficiency decreased as I2 increased in the bath. This suggests that I3- is reduced in agreement with equation (ii) as silver is deposited:
I3-+2e-→3I-……(ii)
