From Fig. 2b, it was observed that experimental M/z values
obtained during cobalt electrodeposition in a solution of pH 5.40
moved toward a value of 32.00 gmol
−1 as the deposition advanced
in the cathodic direction. This result suggests that deposition is
occurring in agreement with Eq. (1). Already at pH 2.70,M/z values
tended toward a value of 13.00 gmol
−1.
This result suggests that cobalt electrodeposition might be
occurring via the formation reaction of Co(OH)2 or by the mecha-
nismof adsorbed hydrogen. As observed byMatsushima et al. [11],
however, the formation of Co(OH)2 does not occur in solutions of
pH< 2.70. Therefore, the decrease in observed M/z values might be
associated with the formation of adsorbed hydrogen. This reaction
occurred in solutions with pH< 2.70 when H3BO3 was added as a
buffer to prevent local pH variations in the solution. Experimental
Turning to the anodic scan, cobalt deposition continues until
reachedthepotential of−0.1V,whenis observeda currentpeakdue
to the cobalt electrodissolution (Fig. 2a). In Fig. 2b is observed that
the ratio M/z increase to 60.00 gmol
−1. That resulted indicate that
themetallic Co electrodissolution occurs through a formation of an
intermediary Co1+ in the interface metal solution. In the following
stage, the Co+ is oxidized to Co2+, as can be see in Eq. (11). Finally,