The Au(111)/Electrolyte Interface: A Tunnel‐Spectroscopic and DFT Investigation

Simeone, Felice C.; Kolb, Dieter M.; Venkatachalam, Sudha; Jacob, Timo

doi:10.1002/anie.200702868

Cited by 47 publications

(50 citation statements)

References 30 publications

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“…This change mainly stems from the negative charge of SO 4 (ads), which releases electrons by the adsorption, but still has a large negative charge of about -1 e. Both the excess charges of Pt and H 2 O(ads) become positive and partially cancel the negative charge of SO 4 (ads). Our result on the charge distribution is similar to that obtained by a distance tunneling spectroscopy combined with DFT calculations on sulfuric acid anion on Au(111), 96,97 while hydronium ion instead of H 2 O(ads) is coadsorbed with sulfate and screens the negative charge of SO 4 (ads) in the case of Au(111).…”

Section:  21supporting

confidence: 87%

First principles study of sulfuric acid anion adsorption on a Pt(111) electrode

Jinnouchi

Hatanaka

Morimoto

et al. 2012

Phys. Chem. Chem. Phys.

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Section:  21supporting

confidence: 87%

First principles study of sulfuric acid anion adsorption on a Pt(111) electrode

Jinnouchi

Hatanaka

Morimoto

et al. 2012

Phys. Chem. Chem. Phys.

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“…While tunnelling barriers in vacuum are usually in the 4-5-eV range, depending on the work function of the electrode material used, the corresponding values in aqueous solution drop to about 1-2 eV (refs [9][10][11][12][13]. This is at least in part due to image charge effects, the local ion distribution and solvent polarization, and results in an increase of the effective tunnelling distance by roughly a factor of two for the barrier values given above 14,15 .…”

Section: Tunnelling Transport In Liquid-filled Electrode Junctionsmentioning

confidence: 99%

Electrochemical tunnelling sensors and their potential applications

Albrecht

2012

Nat Commun

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the quantum-mechanical tunnelling effect allows charge transport across nanometre-scale gaps between conducting electrodes. application of a voltage between these electrodes leads to a measurable tunnelling current, which is highly sensitive to the gap size, the voltage applied and the medium in the gap. applied to liquid environments, this offers interesting prospects of using tunnelling currents as a sensitive tool to study fundamental interfacial processes, to probe chemical reactions at the single-molecule level and to analyse the composition of biopolymers such as Dna, rna or proteins. this offers the possibility of a new class of sensor devices with unique capabilities. E lectrochemical sensors based on measuring the tunnelling current across nanoscale electrode junctions in solution are emerging as a new class of single-molecule sensors. They combine extremely high spatial resolution with sensitivity to the electronic structure of the analyte. This opens up perspectives towards the label-free detection of small molecules, the characterization of catalytic or enzymatic processes at the single-molecule level as well as the analysis of biopolymers with sub-molecular resolution, Fig. 1. To this end, label-free, fast and inexpensive RNA and DNA sequencing may be in reach, potentially revolutionizing the way we perform gene sequencing today.Charge transfer by quantum-mechanical tunnelling is one of the most ubiquitous elementary processes in nature and features in areas as diverse as electron or hydrogen transfer in enzymatic reactions, interfacial charge transfer at metal electrodes in solution, thin-layer devices in electronics, charge transfer between crystal defects and radioactive α-decay 1 . Important applications exploiting tunnelling transport include the Esaki tunnelling diode and the scanning tunnelling microscope (STM)-both recognized with the Nobel Prize in Physics for their inventors, namely Esaki in 1973 (jointly with Josephson), and Binnig and Rohrer in 1986, respectively.'Tunnelling' refers to the transport of electrons (or other light charge carriers) across a nanometre-sized gap, a molecule or even an insulating layer between two electrodes. Upon application of a bias voltage V bias between the two electrodes, negatively charged electrons are more likely to be transported towards the positively biased electrode and a so-called 'tunnelling current' I t is detected. The latter depends exponentially on gap size, which is the reason for the high spatial resolution of STM, the applied voltage V b and the electronic structure of the medium in the gap. To this end, the electrode junction may be represented by a transmission function that characterizes the probability of electrons moving from one electrode across the gap into the second electrode, summarized over all energy levels.Hence, the more accessible the energy levels in the junction, and the better their electronic coupling to the electrodes, the higher current across the junction. This also implies that the tunnelling current is sensitive to ...

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“…Simulated voltammograms obtained in these studies were in good agreement with experimental data. Density functional theory (DFT) calculations of the ( p 3 Â p 7) structure of sulfate on Au(1 1 1) were recently reported by Jacob and coworkers, considering models with sulfate or bisulfate coadsorbed with H 3 O + or water in different combinations [16,22]. According to these ab initio studies the most stable structure was formed by the coadsorption of sulfate and hydronium ions with an arrangement as shown in Fig.…”

Section: Introductionmentioning

confidence: 96%