Electrodeposition from supercritical fluids

Abstract

Recent studies have shown that it is possible to electrodeposit a range of materials, such as Cu, Ag and Ge, from various supercritical fluids, including hydrofluorocarbons and mixtures of CO2 with suitable co-solvents. In this perspective we discuss the relatively new field of electrodeposition from supercritical fluids. The perspective focuses on some of the underlying physical chemistry and covers both practical and scientific aspects of electrodeposition from supercritical fluids. We also discuss possible applications for supercritical fluid electrodeposition and suggest some key developments that are required to take the field to the next stage.

Electrochemistry in supercritical fluids: A mini review

“…Organic co-solvents form a single phase with scCO 2 and considerably improve the solubility of ionic species. This mixed solvent phase has been largely documented in the field electrodeposition [3,18,22], with Bartlett et al recently reviving interest in SCFs as electroplating media. Their research efforts have demonstrated that the unique mass transport properties and lack of surface tension in supercritical media permit the formation of well-defined nano-structured electrodeposits [3].…”

“…This mixed solvent phase has been largely documented in the field electrodeposition [3,18,22], with Bartlett et al recently reviving interest in SCFs as electroplating media. Their research efforts have demonstrated that the unique mass transport properties and lack of surface tension in supercritical media permit the formation of well-defined nano-structured electrodeposits [3]. Other electrochemically driven reactions of interest studied in this mixed solvent phase are electrocarboxylation of benzyl chloride [23] and conducting polymer synthesis [24,25].…”

“…Thus, Atobe et al reported the use of supercritical CHF 3 for the oxidative polymerization of pyrrole and thiophene [34], whilst Bartlett et al have extended their electrodeposition studies to fluorinated supercritical media [3,35]. Furthermore, the utilisation of scHFCs as media for CO 2 reduction has been considered with promising results from the unique fluid [36].…”

“…The predominant electrochemical application of SCFs to-date has been in electrodeposition, a subject comprehensively reviewed recently [3]. The electrochemistry of SCFs is overall a complex subject however, with complications arising from pressurised reactor designs, low dielectric constants and poor solubility of supporting electrolytes.…”

Measurements of the double layer capacitance for electrodes in supercritical CO2/acetonitrile electrolytes

“…Figure 1 shows the cell and position of the electrodes. The dry electrolytes were weighed into the cell (described elsewhere [13,22]) in the atmosphere and this was then transferred to the glove box anti-chamber. After 15 h under nitrogen flow the cell was assembled inside the glove box where the dry acetonitrile co-solvent was added.…”