Surface treatment

Electrolytic baths for the electrodeposition of metals

Electrolytic baths for the electrodeposition of metals
Thanks to their high electrochemical stability, ionic liquids offer the possibility to deposit metals that cannot be in aqueous electrolytes while reducing environmental impacts (electrolytic baths without VOC, without cyanide...etc).

The deposits are often of better quality. In addition, by using hydrophobic ionic liquids, we avoid the production of hydrogen bubbles (due to the presence of water) which infiltrate into the metal, leave tiny holes when it evaporates and reduce the adherence of the deposit ¹.
Ionic liquids are seen as an economic alternative to vacuum deposition techniques.

¹ G. Moutiers, I. Billard, Pour la science, 2003, 311, 45

Nanocrystals electrodeposition of metallic oxides

Electrodeposition of ZnO in Ionic Liquid environment ²

Zno is deposited from an electrolyte of (Zn II) TFSI Zinc(II) Bis (trifluoromethanesulfonyl)imide (Zn (II) - ref. M3008c) dissolved in 1-Butyl-1-methylpyrrolidinium Bis(trifluoromethanesulfonyl)imide (Pyr14 TFSI - ref. Pyr0408a) saturated in O2.

                     Nanocristalline film ZnO electrodeposed on FTO

                 Deposit obtained in 150°C in ionic liquid environment

                            Top view                                           Seen in section

The anion of the ionic liquid and the salt being the same (TFSI), the following advantages are observed:

- Good solubility of Zinc salt (II)

- Homogeneous solution in Zn(II)

- No formation of hydroxides of Zn

² E. Azaceta et Al., Electrochem. Commum. 11 (2009) p. 2184