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Electrochemical oxidation as alternative for dissolution of metal oxides in deep eutectic solvents

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journal contribution
posted on 2021-04-23, 14:26 authored by Ioanna M Pateli, Andrew P Abbott, Gawen RT Jenkin, Jennifer M Hartley
Metal oxide dissolution is central to most metal processing and is generally carried out using mineral acids. An alternative approach has been demonstrated for metal sulfides using electrochemical oxidation. Here the so-called paint casting method was employed to investigate the electrochemical dissolution and recovery of selected metal oxides. Cyclic voltammetry showed that all of the metal oxides were electrochemically active in deep eutectic solvent media, and the majority displayed a redox couple that could be potentially assigned to the redox behaviour of the oxide moiety. Bulk anodic dissolution was carried out on the metal oxides, and it was shown that dissolution was enhanced to up to >10000 times in pH neutral solutions. The rate of electrochemical dissolution was shown to be influenced by the band gap of the compounds. It is proposed that oxidation of the oxide moiety, potentially to the superoxide, enables the solubilisation of the metal ions. The metal speciation appears to remain the same as for chemical dissolution.

History

Citation

Green Chem., 2020,22, 8360-8368

Author affiliation

School of Chemistry

Version

  • AM (Accepted Manuscript)

Published in

Green Chemistry

Volume

22

Issue

23

Pagination

8360 - 8368

Publisher

Royal Society of Chemistry

issn

1463-9262

eissn

1463-9270

Acceptance date

2020-10-31

Copyright date

2020

Available date

2021-11-02

Language

English