The effect of valine on the process of nickel electrocrystallization on glassy carbon electrode

•Nickel electrodeposition process on glassy carbon electrode in baths contained valine was investigated.•The presence of valine causes higher nickel steady-state nucleation rate, while higher solution pH weakens this effect.•Nickel nucleation follows 3D progressive mode in our experiments, despite the variation of pH and valine concentration.

The effects of valine concentration and solution pH on nickel electrocrystallization on glassy carbon electrode were studied with linear sweep cyclic voltammetry and single potential step chronoamperometry. Chronoamperometric results show that the nucleation process of nickel followed progressive 3D nucleation mode. The change in valine concentration and solution pH significantly affect nickel nucleation kinetic process, but do not alter nickel nucleation mode. The increment of valine concentration promotes the nickel steady-state nucleation rates, while the promotion effect becomes less remarkable when solution pH changes from 4.0 to 5.0.