IN-SITU ATOMIC-FORCE MICROSCOPY OBSERVATION OF CHANGE IN THICKNESS OFNICKEL-HYDROXIDE LAYER ON NI ELECTRODE

The layer of nickel hydroxide was formed electrochemically on the redu ced surface of polycrystalline Ni in 1 M KOH. The layer thickness of 8 .5 nm, estimated by an electrochemical method, corresponded to about 1 0 monolayers of Ni(OH)(2). In situ atomic force microscopy (AFM) with the tip fixed was applied to monitor the changes of nickel hydroxide f ilm thickness during the process of its oxidation and reduction. The p rocess of oxidation resulted in the film thickness decreasing by about 3 nm. This change could be explained as due to the removal of a proto n from the Ni(OH)(2) layer.