GALVANOSTATIC STUDY OF THE ELECTROCRYSTALLIZATION OF BINARY NICKEL-BASE ALLOYS .1. ZN-NI ALLOY ON GLASSY-CARBON

The nucleation and growth mechanisms for zinc, nickel and Zn-Ni deposi tion on glassy carbon were studied by linear sweep voltammetry, as wel l as by potentiostatic and galvanostatic polarization. Galvanostatic p olarization makes it possible to determine the coverage of the substra te at the start of the deposition process and usually to determine the current density that prevents strong hydrogen evolution. For zinc and Zn-Ni depositions, the first step after applying a current, is the fo rmation of hydrogen, which emphasizes the need for hydrogen as an inte rmediate species for zinc deposition. Zn-Ni deposition is preceded by pure zinc deposition.