Open Access

Isman M. Khazi, Ulrich Mescheder, Jürgen Wilde

• The approach of using current transients to model the nucleation rate as reported in the seminal work of Scharifker and Mostany is limited to electrodeposition system without bath hydrodynamics (BHD). Therefore, in this work in situ electroanalytical approach is proposed to unveil the influence of BHD on the nucleation kinetics of electrochemically deposited Nickel-Cobalt alloy system (eNiCo). Using the Hydrodynamic linear sweep voltammetry (HLSV) technique, the limiting current density as a function of BHD is computed, wherein it increased (for eNiCo alloys) from 186 mA/cm² to 222.6 mA/cm² on increasing BHD from 0 to 42 cm/s, respectively. Consecutively, the diffusion layer thickness is found to decrease from 19 µm to ca. 15.8 µm on increasing BHD from 0 to 42 cm/s, respectively. Additionally, from Nyquist plots recorded using the Galvanostatic Electrochemical Impedance Spectroscopy (GEIS), the charge transfer coefficient (Rct), exchange current density (io) and double layer capacitance (Cdl) as a function of BHD is computed. It is found that Rct decreased and io, Cdl increased as function of BHD. Thereby, indicating the enhancement in the charge transfer on the cathode surface and reduction in the thickness of the diffusion layer. Hence, with the use of BHD, it is possible to control the growth kinetics, therefore enabling the deposition of tailor-made materials possessing specific required properties.