Related Experiment Video
Updated: May 27, 2026
08:32
Electrochemical Roughening of Thin-Film Platinum Macro and Microelectrodes
Published on: June 30, 2019
Diffusional surface voltammetry as a probe of adsorption energetics
Juan José Calvente1, Miguel Molero, Rafael Andreu
1Departamento de Química Física, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain. pacheco@us.es
Analytical Chemistry
|December 2, 2011
Summary
Diffusional surface voltammetry (DSV) now quantifies adsorption free energy for low surface coverages. This technique determines group contributions to adsorption, linking hydrophobicity to interfacial behavior.
Area of Science:
- Electrochemistry
- Surface Science
- Physical Chemistry
Background:
- Determining adsorption free energy at low surface coverages (Henry limit) requires sensitive techniques.
- Existing methods struggle with high sensitivity to both amount and energetics of adsorbed molecules.
Purpose of the Study:
- To demonstrate diffusional surface voltammetry (DSV) for direct determination of adsorption free energy at extremely low surface coverages.
- To derive a general analytical expression for DSV surface voltammetric peak potential.
- To establish strategies and diagnostic criteria for quantitative insight into electrosorption energetics.
Main Methods:
- Derivation of a general analytical expression for the surface voltammetric peak potential of DSV.
- Utilizing DSV in its stripping mode to determine group contributions to adsorption free energy.
- Applying the protocol to homologous series of alkylthiolates adsorbed at mercury electrodes.
Main Results:
- DSV successfully determines adsorption free energy for electroactive adsorbates at low surface coverages.
- Group contributions of CH(n) groups (n=0-3) to adsorption free energy were quantified for alkylthiolates.
- Adsorption energetics correlate linearly with hydrophobicity, as indicated by octanol-water partition coefficients.
Conclusions:
- DSV enhances the capability to probe adsorption energetics down to the micromolar level.
- The study provides a unified approach for treating stripping and film voltammetries.
- Adsorption of hydrocarbon groups at the mercury/solution interface is governed by hydrophobicity.
More Related Videos
10:59Tracking Electrochemistry on Single Nanoparticles with Surface-Enhanced Raman Scattering Spectroscopy and Microscopy
Published on: May 12, 2023
08:31Probing Surface Electrochemical Activity of Nanomaterials using a Hybrid Atomic Force Microscope-Scanning Electrochemical Microscope (AFM-SECM)
Published on: February 10, 2021
Related Concept Videos
01:12Voltammetric Techniques: Linear-Scan (E vs Time)
Polarography is a classical voltammetric technique used to analyze electrochemical reactions. This method applies a linear potential sweep to a dropping mercury electrode (DME), and the resulting current is measured. A dropping mercury electrode is commonly used as the working electrode in polarography. It consists of a capillary tube filled with mercury, where the tiny droplet forms at the tip. This droplet continuously drops from the capillary, creating a new electrode surface for each...
01:13Voltammetry: Stripping Methods
Anodic Stripping Voltammetry (ASV), Cathodic Stripping Voltammetry (CSV), and Adsorptive Stripping Voltammetry (AdSV) are electrochemical techniques used to determine trace amounts of analytes in solution. These methods involve applying a potential to an electrode and measuring the resulting current.
Anodic Stripping Voltammetry (ASV)
ASV is used to determine metals and metalloids at trace levels. It involves two steps: deposition and stripping. First, a negative potential is applied to the...
Anodic Stripping Voltammetry (ASV)
ASV is used to determine metals and metalloids at trace levels. It involves two steps: deposition and stripping. First, a negative potential is applied to the...
01:16Voltammograms: Overview
Voltammograms are current plots as a function of applied potential, offering insights into electrochemical systems. The shape of a voltammogram depends on how the current is measured and whether convection (heat transfer by fluid movement) is present or absent.
Shapes of Voltammograms
Shapes of Voltammograms
01:21Voltammetry: Factors Affecting Measurements
A current produced due to the redox reactions of the analyte at the working and auxiliary electrodes is called a faradaic current. The reaction can be divided into two types. The current generated due to the reduction of the analyte is called cathodic current, and it carries a positive charge. In contrast, the current produced by analyte oxidation is known as an anodic current, and it has a negative charge. The applied potential at the working electrode determines the faradaic current flow, and...
01:17Voltammetric Techniques: Pulse Voltammetry
Differential-pulse voltammetry (DPV) is a type of voltammetry that involves applying a series of voltage pulses to an electrochemical cell while measuring the resulting current. In DPV, the differential pulse or small potential pulses are superimposed on a linear potential sweep. The magnitude of these pulses is typically small, often in the millivolt range. Each voltage pulse lasts a short duration, usually in the order of a few milliseconds, and is applied at regular intervals along the...
01:20Voltammetry: Overview
Voltammetry is an electroanalytical technique in which the current flowing through an electrochemical cell is measured as a function of applied potential, typically under conditions of concentration polarization. The technique provides valuable information about redox-active species, and the current response is plotted as a voltammogram.
A voltammetric cell uses three electrodes: a working electrode, a reference electrode, and an auxiliary electrode. The redox reactions occur in the working...
A voltammetric cell uses three electrodes: a working electrode, a reference electrode, and an auxiliary electrode. The redox reactions occur in the working...