抄録
The color of copper anode film has a tendency to change in the following sequence: from redish brown or brown to black and from black to blue or green, according to the increase of bath voltage. The X-ray diffraction tests show that the film is composed of a small amount of Cu2O for the redish brown or brown color, CuO for the black color, and CuCN for the blue or green color.
In each case the film is formed when the bath voltage is higher than 2.5V. At the start of plating a comparatively great amount of film is formed at the rate of 0.1g/dm2/hr. There is no indication of weight increase for two hours.
In this experiment the plating solution was 1.5l, and the electrode surface area was 0.2 to 2dm2.
