M. Kitano et M. Shiojiri, ELECTROCHEMICAL REACTION OF ZN IN WATER AND GROWTH OF ZNO PARTICLES, Journal of the Electrochemical Society, 144(3), 1997, pp. 809-815
The electrochemical reactions on a Zn anode and a Pt cathode in water
at 25 degrees C and the growth of ZnO particles are investigated by x-
ray diffraction, scanning electron microscopy, and high-resolution tra
nsmission electron microscopy. The solution pH, current, and weight of
the anode were measured as a function of the voltage applied between
the anode and cathode from 10 to 400 V. At voltages below 100 V the di
ssolution of Zn occurs on the anode, and above 100 V the formation of
ZnO also takes place. The applied current generates OH- at the cathode
. Initially, when the pH is lower, ZnO nano-sized particles are deposi
ted on the cathode. When the pH of the water increases, Zn2+ combines
with OH- to form spindle-like ZnO particles as long as 1 mu m.