Effect of magnetic stirring on microstructure of Co deposit in electrowinning

The effect of magnetic stirring was investigated on the microstructure of Co deposits during electrowinning in a chloride solution. The microstructure of Co deposits obtained before and after using the magnetic stirring was systemically characterized. Cyclic voltammograms were carried out to investigate the electro-reduction of Co2+ ions. The nucleation and growth of Co deposits were discussed based on chronoamperometry. The evolution of H2 inevitably accompanied with the reduction of Co2+ ions in the electrowinning. It had a great influence on the structure of Co deposits. The introducition of magnetic stirring can reduce this negative influence effectively by promoting the detachment of H2 bubbles on the substrate. The magnetic stirring also changed the nucleation and growth of Co deposits. Finally, columnar Co crystals with intensively preferred orientation were prepared. The modification of microstructure by magnetic stirring is contributed to prepare high-quality Co electrodeposits.

Automated summary

This study investigated the effect of magnetic stirring on the microstructure of Co deposits during electrowinning in a chloride solution. It was found that magnetic stirring effectively reduced the negative influence of H2 bubbles on the structure of Co deposits and changed their nucleation and growth behavior, resulting in the preparation of high-quality columnar Co crystals.