Pulse electrodeposition of Cr–SWCNT composite from choline chloride based electrolyte

Abstract

Using an environmentally benign choline chloride based deep eutectic solvent (DES), chromium (Cr) and chromium–single walled carbon nanotube (Cr–SWCNT) composite coatings on copper (Cu) substrate were developed by pulse electrodeposition (PED) method. The cyclic voltammetry studies of Cr³⁺ choline chloride based DES system showed that the reduction of Cr³⁺ to Cr⁰ occurs via two-step process. The effect of SWCNTs on the thickness, current efficiency and hardness of the deposits were examined. The SWCNTs improved the hardness and corrosion resistance properties of composite coating. Crystallographic phases, structural morphology, topography and corrosion resistance were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission (FE)-SEM, atomic force microscopy (AFM) and potentiodynamic polarisation techniques respectively. Structural morphological data revealed uniform distribution of SWCNTs in the chromium metal matrix.

Keywords:

• Carbon nanotubes
• Composite coating
• Deep eutectic solvent
• Pulse electrodeposition

Acknowledgements

One of the authors (Dr S. Mohan) thanks the Department of Science and Technology New Delhi, for a research grant under SERC (engineering sciences) scheme no. SR/S3/ME/0030/2009.