Influence of nettle extract on zinc electrodeposition in an acidic bath: Electrochemical effect and coating morphology

Abstract

The electrodeposition of zinc from an acidic sulphate bath was studied in the presence of nettle (Urtica dioica L.) extract at room temperature and with relative low zinc concentration. Different electrochemical measurements show that the nettle extract allows a reduction of hydrogen adsorption on steel and zinc and therefore a decrease in hydrogen evolution, due to the specific adsorption of molecules of the extract. Scanning electron microscopy (SEM) observations and X-ray diffraction (XRD) measurements reveal that the addition of nettle extract induces a very fine grain size with a random crystallographic orientation. Finally, the nettle extract constitutes an interesting and low cost additive for all processes based on zinc electrochemical reduction in acidic sulphate electrolytes.