Figure 3. Reaction product of a cathodic corrosion using a copper electrode. A brown suspension can be observed, scattering the light of a laser beam

From

Electrochemical Synthesis of Coin Metal Nanoparticles in School Chemistry Education

Elena von Hoff, Stefanie Waitz, Felix Kollenda, Thomas Waitz

World Journal of Chemical Education. 2018, 6(1), 72-77 doi:10.12691/wjce-6-1-11