Abstract
The time-variation of hydrogen gas quantity evolved during zinc electroplating from an alkaline zincate bath containing additives was evaluated using an electronic balance, since the hydrogen gas caused buoyancy to the working electrode arranged in the parallel to the solution surface.
The ease of hydrogen evolution on metal electrodes in alkaline zincate bath was order of nickel≥SUS304> iron>copper, which was also the decreasing order of hydrogen-overpotential of these electrodes.
At the beginning of electroplating, there was remarkable hydrogen evolution and retardation of zinc deposition on the iron electrode. On the other hand, zinc deposition promptly started on the copper electrode, for which hydrogenoverpotential was greater than that of the iron electrode, which resulted in the suppression of hydrogen evolution.
