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 deposition on glassy carbon were studied by linear sweep voltammetry, as well as by potentiostatic and galvanostatic polarization. Galvanostatic polarization makes it possible to determine the coverage of the substrate 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 formation of hydrogen, which emphasizes the need for hydrogen as an intermediate species for zinc deposition. Zn-Ni deposition is preceded by pure zinc deposition.