1993 Volume 42 Issue 10 Pages 648-652
We studied the initial stage of electrodeposition of copper on gold electrode in 0.1M CuSO4+0.6% H2SO4 aqueous solution by using a scanning tunneling microscope (STM). We have found that the enhanced electrodeposition occurred under STM tip when the tunnel current was increased. The electrodeposition rate was strongly dependent on the tunnel current but not on the potential of gold electrode, and became 7600 times faster than that estimated from catholic polarization curve of gold as the tunnel current was increased. The STM observation after the test showed that the electrodeposition of copper occurred only under the STM tip. It may be considered from these results that some part of the tunnel current was consumed to the electrochemical reaction.