Wien effect in interfacial water dissociation through proton-permeable graphene electrodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36182944.
- Also identified by DOI 10.1038/s41467-022-33451-1 and PMC identifier 9526707.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Strong electric fields can accelerate molecular dissociation reactions. The phenomenon known as the Wien effect was previously observed using high-voltage electrolysis cells that produced fields of about 10<sup>7</sup> V m<sup>-1</sup>, sufficient to accelerate the dissociation of weakly bound molecules (e.g., organics and weak electrolytes). The observation of the Wien effect for the common case of water dissociation (H<sub>2</sub>O [Formula: see text] H<sup>+</sup> + OH<sup>-</sup>) has remained elusive. Here we study the dissociation of interfacial water adjacent to proton-permeable graphene electrodes and observe strong acceleration of the reaction in fields reaching above 10<sup>8</sup> V m<sup>-1</sup>. The use of graphene electrodes allows measuring the proton currents arising exclusively from the dissociation of interfacial water, while the electric field driving the reaction is monitored through the carrier density induced in graphene by the same field. The observed exponential increase in proton currents is in quantitative agreement with Onsager's theory. Our results also demonstrate that graphene electrodes can be valuable for the investigation of various interfacial phenomena involving proton transport.