Electrochemical co-deposition of carbon nanotube/Ni composite layer

The type and content of particles in the plating solution greatly affect the electrodeposition process, making it important to study the effect of carbon nanotubes (CNTs) on the electrodeposition of nickel during the preparation of CNTs/Ni composites. In this paper, cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometric analysis (CA), and electrochemical impedance spectroscopy (EIS) were adopted to study the nucleation mechanism in the early stage of electrocrystallization. Field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) were used to reveal the electrocrystallization properties. The results showed that Ni was electrodeposited by 3D nucleation/growth and was controlled by diffusion and electrochemical kinetics. Increasing the CNTs concentration shortened the time required for 3D growth. Additionally, the polarizability of the electrodeposited nickel increased upon increasing the CNTs content, which helped increase the electro-crystallization probability of Ni. As the concentration of CNTs increased, the charge transfer resistance decreased, the Ni nucleation activation energy decreased, and the Ni nucleation became easier. The introduction of CNTs changed the preferred growth orientation of pure nickel, and the surface growth morphology was mainly a spiral in a stepwise pyramid.