1
|
Comparison between polycrystalline Au and single-crystalline Au(1 1 1) electrodes as the substrate of a cationic organic monolayer based on their anion dependent redox activities. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
2
|
Nahalka I, Zwaschka G, Campen RK, Marchioro A, Roke S. Mapping Electrochemical Heterogeneity at Gold Surfaces: A Second Harmonic Imaging Study. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2020; 124:20021-20034. [PMID: 35693431 PMCID: PMC9182208 DOI: 10.1021/acs.jpcc.0c02740] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/31/2020] [Indexed: 05/25/2023]
Abstract
Designing efficient catalysts requires correlating surface structure and local chemical composition with reactivity on length scales from nanometers to tens of microns. While much work has been done on this structure/function correlation on single crystals, comparatively little has been done for catalysts of relevance in applications. Such materials are typically highly heterogeneous and thus require methods that allow mapping of the structure/function relationship during electrochemical conversion. Here, we use optical second harmonic imaging combined with cyclic voltammetry to map the surface of gold nanocrystalline and polycrystalline electrodes during electrooxidation and to quantify the spatial extent of surface reconstruction during potential cycling. The wide-field configuration of our microscope allows for real-time imaging of an area ∼100 μm in diameter with submicron resolution. By analyzing the voltage dependence of each pixel, we uncover the heterogeneity of the second harmonic signal and quantify the fraction of domains where it follows a positive quadratic dependence with increasing bias. There, the second harmonic intensity is mainly ascribed to electronic polarization contributions at the metal/electrolyte interface. Additionally, we locate areas where the second harmonic signal follows a negative quadratic dependence with increasing bias, which also show the largest changes during successive cyclic voltammetry sweeps as determined by an additional correlation coefficient analysis. We assign these areas to domains of higher roughness that are prone to potential-induced surface restructuring and where anion adsorption occurs at lower potentials than expected based on the cyclic voltammetry.
Collapse
Affiliation(s)
- Igor Nahalka
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
and Institute of Materials Science (IMX), School of Engineering (STI),
and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Gregor Zwaschka
- Fritz
Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - R. Kramer Campen
- Fritz
Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
- Faculty
of Physics, University of Duisburg-Essen, Lotharstraße 1, 47057 Duisburg, Germany
| | - Arianna Marchioro
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
and Institute of Materials Science (IMX), School of Engineering (STI),
and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
and Institute of Materials Science (IMX), School of Engineering (STI),
and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| |
Collapse
|
3
|
Morooka T, Tahara H, Sagara T. Effect of bromide adsorption on electrowetting of Au electrode with hexadecane. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.08.133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
4
|
Lazarescu V, Scurtu R, Lazarescu MF, Toader AM, Volanschi E, Santos E, Jones H, Götz G, Bäuerle P. Potential-induced conformational changes in an alpha-CN-terthiophene thiolate film on GaAs(110). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:6522-6531. [PMID: 19374442 DOI: 10.1021/la900043k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Second harmonic generation (SHG) investigations on alpha-CN-terthiophene-thiolate-covered GaAs(110) electrodes in 1 N H2SO4 solution revealed significant changes in the rotational anisotropy of the SH response. The enhancement of the 1- and the 3-fold contributions around -250 mV suggests changes in the symmetry properties of the delocalized electron system due to an alteration of the adsorption geometry induced by the applied potentials. The analysis of the EIS data showed that in the potential region where the SH signal exhibits the more important changes the Mott-Schottky plot undergoes a pronounced shift to more negative potentials as a result of the charging of the surface states grouped about 1.06 eV below the conduction band edge. Semiempirical MO calculations suggest that the most energetically favorable interaction implies electron transfer from the semiconductor conduction band to the lowest unoccupied molecular orbital of the organic molecule with epsilon(LUMO)=-1.707 eV. Such a chemisorption bond bringing the organic molecule to a quasi-planar position is well supported by the major changes in the XPS spectra of the electrochemically biased samples with respect to the as-prepared ones. Two distinct N 1s species instead of one and a shift of 1.6 eV to higher BE of the terthiophene S 2s core level are strong evidence for a potential-induced change in the adsorption geometry. Taking into account that the acceptor-like surface state group located close to the semiconductor valence edge (EC,S=-1.06 eV) may correspond to the LUMO level (shifted downward by the adsorption process), we assume that the organic molecule, initially adsorbed by the thiolate end, undergoes a conformational change from a tilted to an almost flat position when the applied potential brings the semiconductor Fermi level into its neighborhood. This assumption is in a very good agreement with the potential-induced variation in the thiol thickness estimated from the thiol capacitance.
Collapse
Affiliation(s)
- Valentina Lazarescu
- Institute of Physical Chemistry Ilie Murgulescu, Spl. Independentei 202, Bucharest, RO-060021 Romania.
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
|
6
|
Danckwerts M, Li YJ, Oslonovitch J, Pettinger B, Krischer K. Adsorption of Camphor on Au(111) and Its Effect on the Electroreduction of Periodate (IO4-). J Phys Chem B 2004. [DOI: 10.1021/jp049920k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matthias Danckwerts
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany, and Physics Department E19, Technische Universität München, James-Franck-Strasse 1, 85748 München, Germany
| | - Yong-Jun Li
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany, and Physics Department E19, Technische Universität München, James-Franck-Strasse 1, 85748 München, Germany
| | - Julia Oslonovitch
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany, and Physics Department E19, Technische Universität München, James-Franck-Strasse 1, 85748 München, Germany
| | - Bruno Pettinger
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany, and Physics Department E19, Technische Universität München, James-Franck-Strasse 1, 85748 München, Germany
| | - Katharina Krischer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany, and Physics Department E19, Technische Universität München, James-Franck-Strasse 1, 85748 München, Germany
| |
Collapse
|
7
|
Mishina E, Miyakita Y, Yu QK, Nakabayashi S, Sakaguchi H. Nonlinear optical properties of oligothiophene self-assembled monolayers on gold substrate. J Chem Phys 2002. [DOI: 10.1063/1.1494420] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
8
|
Radiotracer study of thallium underpotential deposition on a polycrystalline gold electrode in alkaline solutions. J Electroanal Chem (Lausanne) 2000. [DOI: 10.1016/s0022-0728(00)00289-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
9
|
Lipkowski J. 1998 Alcan Award Lecture Surface electrochemistry - surface science with a joy stick. CAN J CHEM 1999. [DOI: 10.1139/v99-124] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This lecture gives a review of thermodynamic, spectroscopic, STM and AFM imaging, and X-ray diffraction studies of molecular and ionic adsorption at Au(111) electrodes. In the first part, thermodynamics of adsorption of simple ions such as sulfate, chloride, bromide, and iodide will be discussed. At high coverages, anions adsorbed at a single crystal surface form ordered 2D adlayers. We show that the structure of these adlayers can be studied by STM and surface X-ray diffraction techniques. Next, the information concerning adsorption of simple ions is used to describe mixed adlayers formed by coadsorption of anions and metal adatoms. We demonstrate how to combine electrochemical experiments with in situ polarization-dependent Cu K-edge X-ray absorption spectroscopy to determine the composition and the structure of mixed films formed by deposition of Cu on Au(111) in the presence of SO42-. In the last part we review our efforts to describe coordination of organic molecules to gold electrodes. First, we will discuss adsorption of benzonitrile at the Au(111) electrode surface. We combine electrochemical methods with in situ infrared spectroscopy to describe (i) the energetics of molecular adsorption at the gold electrode surface, (ii) the character of the interaction of the adsorbed molecule with the metal substrate, and (iii) the influence of the electric field on the orientation of the adsorbed molecule. In the last section we describe surface aggregation phenomena. We apply AFM and STM to determine the structure of hemimicelles formed at the Au(111) electrode surface by adsorbed molecules of sodium dodecyl sulfate and we discuss the potential-controlled transformation of these hemimicelles into a condensed monolayer.Key words: surface electrochemistry, electrosorption, surface aggregation, gold electrodes, molecular adsorption, ionic adsorption.
Collapse
|
10
|
Chen A, Shi Z, Bizzotto D, Lipkowski J, Pettinger B, Bilger C. Iodide adsorption at the Au(111) electrode surface. J Electroanal Chem (Lausanne) 1999. [DOI: 10.1016/s0022-0728(98)00437-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
11
|
Pettinger B, Bilger C, Beltramo G, Santos E, Schmickler W. Interference second harmonic anisotropy at single crystalline silver-electrodes. Electrochim Acta 1998. [DOI: 10.1016/s0013-4686(98)00192-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
12
|
|
13
|
Pettinger B, Bilger C. A novel approach to analyze the optical second harmonic generation anisotropy at surfaces employing interference techniques. Example: the Au(110) electrode. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(97)01471-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
14
|
Richard KM, Gewirth AA. Effects of Ring Substitution on the Binding and Oxidation of Cyanophenols on Au(111) Electrodes. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp953709e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine M. Richard
- Department of Chemistry, University of Illinois, 600 S. Mathews, Urbana, Illinois 61801
| | - Andrew A. Gewirth
- Department of Chemistry, University of Illinois, 600 S. Mathews, Urbana, Illinois 61801
| |
Collapse
|