Abstract
Adsorption often dominates the response of nanofluidic systems due to their high surface-to-volume ratios. Here we harness this sensitivity to investigate the reversible adsorption of outer-sphere redox species at electrodes, a phenomenon that is easily overlooked in bulk measurements. We find that even though adsorption does not necessarily play a role in the electron-transfer process, such adsorption is nevertheless ubiquitous for the widely used outer-sphere species. We investigate the physical factors driving adsorption and find that this counterintuitive behavior is mediated by the anionic species in the supporting electrolyte, closely following the well-known Hofmeister series. Our results provide foundations both for theoretical studies of the underlying mechanisms and for contriving strategies to control adsorption in micro/nanoscale electrochemical transducers where surface effects are dominant.
Original language | English |
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Pages (from-to) | 636-640 |
Number of pages | 5 |
Journal | The journal of physical chemistry letters |
Volume | 5 |
Issue number | 3 |
DOIs | |
Publication status | Published - 6 Feb 2014 |
Keywords
- adsorption
- Hofmeister series
- nanofluidics
- outer-sphere species
- redox cycling