101
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Zhang G, Güell AG, Kirkman PM, Lazenby RA, Miller TS, Unwin PR. Versatile Polymer-Free Graphene Transfer Method and Applications. ACS APPLIED MATERIALS & INTERFACES 2016; 8:8008-16. [PMID: 26953499 DOI: 10.1021/acsami.6b00681] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A new method for transferring chemical vapor deposition (CVD)-grown monolayer graphene to a variety of substrates is described. The method makes use of an organic/aqueous biphasic configuration, avoiding the use of any polymeric materials that can cause severe contamination problems. The graphene-coated copper foil sample (on which graphene was grown) sits at the interface between hexane and an aqueous etching solution of ammonium persulfate to remove the copper. With the aid of an Si/SiO2 substrate, the graphene layer is then transferred to a second hexane/water interface to remove etching products. From this new location, CVD graphene is readily transferred to arbitrary substrates, including three-dimensional architectures as represented by atomic force microscopy (AFM) tips and transmission electron microscopy (TEM) grids. Graphene produces a conformal layer on AFM tips, to the very end, allowing easy production of tips for conductive AFM imaging. Graphene transferred to copper TEM grids provides large-area, highly electron-transparent substrates for TEM imaging. These substrates can also be used as working electrodes for electrochemistry and high-resolution wetting studies. By using scanning electrochemical cell microscopy, it is possible to make electrochemical and wetting measurements at either a freestanding graphene film or a copper-supported graphene area and readily determine any differences in behavior.
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Affiliation(s)
- Guohui Zhang
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Aleix G Güell
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Paul M Kirkman
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Robert A Lazenby
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Thomas S Miller
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
| | - Patrick R Unwin
- Department of Chemistry, University of Warwick , Coventry CV4 7AL, United Kingdom
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102
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Tan SY, Zhang J, Bond AM, Macpherson JV, Unwin PR. Impact of Adsorption on Scanning Electrochemical Microscopy Voltammetry and Implications for Nanogap Measurements. Anal Chem 2016; 88:3272-80. [PMID: 26877069 DOI: 10.1021/acs.analchem.5b04715] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Sze-yin Tan
- Department
of Chemistry, University of Warwick, Coventry, West Midlands CV4 7AL, United Kingdom
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Jie Zhang
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Alan M. Bond
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Julie V. Macpherson
- Department
of Chemistry, University of Warwick, Coventry, West Midlands CV4 7AL, United Kingdom
| | - Patrick R. Unwin
- Department
of Chemistry, University of Warwick, Coventry, West Midlands CV4 7AL, United Kingdom
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103
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Li Z, Kozbial A, Nioradze N, Parobek D, Shenoy GJ, Salim M, Amemiya S, Li L, Liu H. Water Protects Graphitic Surface from Airborne Hydrocarbon Contamination. ACS NANO 2016; 10:349-359. [PMID: 26673269 DOI: 10.1021/acsnano.5b04843] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The intrinsic wettability of graphitic materials, such as graphene and graphite, can be readily obscured by airborne hydrocarbon within 5-20 min of ambient air exposure. We report a convenient method to effectively preserve a freshly prepared graphitic surface simply through a water treatment technique. This approach significantly inhibits the hydrocarbon adsorption rate by a factor of ca. 20×, thus maintaining the intrinsic wetting behavior for many hours upon air exposure. Follow-up characterization shows that a nanometer-thick ice-like water forms on the graphitic surface, which remains stabilized at room temperature for at least 2-3 h and thus significantly decreases the adsorption of airborne hydrocarbon on the graphitic surface. This method has potential implications in minimizing hydrocarbon contamination during manufacturing, characterization, processing, and storage of graphene/graphite-based devices. As an example, we show that a water-treated graphite electrode maintains a high level of electrochemical activity in air for up to 1 day.
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Affiliation(s)
- Zhiting Li
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Andrew Kozbial
- Department of Chemical & Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Nikoloz Nioradze
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - David Parobek
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Ganesh Jagadeesh Shenoy
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Muhammad Salim
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Shigeru Amemiya
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Lei Li
- Department of Chemical & Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
- Department of Mechanical Engineering & Materials Science, Swanson School of Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Haitao Liu
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
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104
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Kiuchi H, Kondo T, Sakurai M, Guo D, Nakamura J, Niwa H, Miyawaki J, Kawai M, Oshima M, Harada Y. Characterization of nitrogen species incorporated into graphite using low energy nitrogen ion sputtering. Phys Chem Chem Phys 2016; 18:458-65. [PMID: 26615959 DOI: 10.1039/c5cp02305j] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The electronic structures of nitrogen species incorporated into highly oriented pyrolytic graphite (HOPG), prepared by low energy (200 eV) nitrogen ion sputtering and subsequent annealing at 1000 K, were investigated by X-ray photoelectron spectroscopy (XPS), angle-dependent X-ray absorption spectroscopy (XAS), and Raman spectroscopy. An additional peak was observed at higher binding energy of 401.9 eV than 400.9 eV for graphitic1 N (graphitic N in the basal plane) in N 1s XPS, where graphitic2 N (graphitic N in the zigzag edge and/or vacancy sites) has been theoretically expected to appear. N 1s XPS showed that graphitic1 N and graphitic2 N were preferably incorporated under low nitrogen content doping conditions (8 × 10(13) ions cm(-2)), while pyridinic N and graphitic1 N were dominantly observed under high nitrogen content doping conditions. In addition, angle-dependent N 1s XAS showed that the graphitic N and pyridinic N atoms were incorporated into the basal plane of HOPG and thus were highly oriented. Furthermore, Raman spectroscopy revealed that low energy sputtering resulted in almost no fraction of the disturbed graphite surface layers under the lowest nitrogen doping condition. The suitable nitrogen doping condition was discovered for realizing the well-controlled nitrogen doped HOPG. The electrochemical properties for the oxygen reduction reaction of these samples in acidic solution were examined and discussed.
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Affiliation(s)
- Hisao Kiuchi
- Department of Applied Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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105
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Zhang W, Zhu S, Luque R, Han S, Hu L, Xu G. Recent development of carbon electrode materials and their bioanalytical and environmental applications. Chem Soc Rev 2016; 45:715-52. [DOI: 10.1039/c5cs00297d] [Citation(s) in RCA: 210] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
New synthetic approaches, materials, properties, electroanalytical applications and perspectives of carbon materials are presented.
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Affiliation(s)
- Wei Zhang
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Shuyun Zhu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Rafael Luque
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Shuang Han
- Shenyang University of Chemical Technology
- Shenyang
- China
| | - Lianzhe Hu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Guobao Xu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
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106
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Gupta R, Singhal M, Nataraj SK, Srivastava DN. A potentiostatic approach of growing polyaniline nanofibers in fractal morphology by interfacial electropolymerization. RSC Adv 2016. [DOI: 10.1039/c6ra21759a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Potentiostatically electropolymerized polyaniline fractals at platinum foil through organic/aqueous interface.
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Affiliation(s)
- Rajeev Gupta
- Analytical Division & Centralized Instrument Facility
- CSIR-Central Salt & Marine Chemicals Research Institute
- Bhavnagar-364002
- India
- Academy of Scientific and Innovative Research
| | - Monika Singhal
- Analytical Division & Centralized Instrument Facility
- CSIR-Central Salt & Marine Chemicals Research Institute
- Bhavnagar-364002
- India
| | | | - Divesh N. Srivastava
- Analytical Division & Centralized Instrument Facility
- CSIR-Central Salt & Marine Chemicals Research Institute
- Bhavnagar-364002
- India
- Academy of Scientific and Innovative Research
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107
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Gira MJ, Tkacz KP, Hampton JR. Physical and electrochemical area determination of electrodeposited Ni, Co, and NiCo thin films. NANO CONVERGENCE 2016; 3:6. [PMID: 28191416 PMCID: PMC5271141 DOI: 10.1186/s40580-016-0063-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 07/14/2015] [Indexed: 05/05/2023]
Abstract
The surface area of electrodeposited thin films of Ni, Co, and NiCo was evaluated using electrochemical double-layer capacitance, electrochemical area measurements using the [Ru(NH[Formula: see text])[Formula: see text]][Formula: see text]/[Ru(NH[Formula: see text])[Formula: see text]][Formula: see text] redox couple, and topographic atomic force microscopy (AFM) imaging. These three methods were compared to each other for each composition separately and for the entire set of samples regardless of composition. Double-layer capacitance measurements were found to be positively correlated to the roughness factors determined by AFM topography. Electrochemical area measurements were found to be less correlated with measured roughness factors as well as applicable only to two of the three compositions studied. The results indicate that in situ double-layer capacitance measurements are a practical, versatile technique for estimating the accessible surface area of a metal sample.
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Affiliation(s)
- Matthew J. Gira
- Department of Physics, Hope College, Holland, MI 49423 USA
- Department of Chemistry, Hope College, Holland, MI 49423 USA
| | - Kevin P. Tkacz
- Department of Physics, Hope College, Holland, MI 49423 USA
- Present Address: Department of Chemical Engineering and Materials Science, University of California, Irvine, CA 92697 USA
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108
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Pavlov SV, Kislenko SA. Effects of carbon surface topography on the electrode/electrolyte interface structure and relevance to Li–air batteries. Phys Chem Chem Phys 2016; 18:30830-30836. [DOI: 10.1039/c6cp05552d] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon surface topography influences the solvent structure at the interface, concentration distribution of reactants (Li+, O2), and their absorption kinetics.
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Affiliation(s)
- S. V. Pavlov
- Joint Institute for High Temperatures of the Russian Academy of Sciences
- Moscow
- Russian Federation
| | - S. A. Kislenko
- Joint Institute for High Temperatures of the Russian Academy of Sciences
- Moscow
- Russian Federation
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109
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Zhang G, Tan SY, Patel AN, Unwin PR. Electrochemistry of Fe3+/2+ at highly oriented pyrolytic graphite (HOPG) electrodes: kinetics, identification of major electroactive sites and time effects on the response. Phys Chem Chem Phys 2016; 18:32387-32395. [DOI: 10.1039/c6cp06472h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Electron transfer kinetics of Fe3+/2+ on HOPG is as fast as on metals, with the electroactivity dominated by basal plane.
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Affiliation(s)
- Guohui Zhang
- Department of Chemistry
- University of Warwick
- Coventry CV4 7AL
- UK
| | - Sze-yin Tan
- Department of Chemistry
- University of Warwick
- Coventry CV4 7AL
- UK
| | - Anisha N. Patel
- Department of Chemistry
- University of Warwick
- Coventry CV4 7AL
- UK
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110
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Maddar FM, Lazenby RA, Patel AN, Unwin PR. Electrochemical oxidation of dihydronicotinamide adenine dinucleotide (NADH): comparison of highly oriented pyrolytic graphite (HOPG) and polycrystalline boron-doped diamond (pBDD) electrodes. Phys Chem Chem Phys 2016; 18:26404-26411. [DOI: 10.1039/c6cp05394g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
NADH electro-oxidation is faster, but more prone to fouling, at HOPG compared to pBDD.
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Affiliation(s)
| | | | - Anisha N. Patel
- Department of Chemistry
- University of Warwick
- Coventry
- UK
- Interfaces, Traitements, Organisation et Dynamique des Systèmes Laboratory
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111
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Huang D, Zhu Y, Su YQ, Zhang J, Han L, Wu DY, Tian ZQ, Zhan D. Dielectric-dependent electron transfer behaviour of cobalt hexacyanides in a solid solution of sodium chloride. Chem Sci 2015; 6:6091-6096. [PMID: 28717449 PMCID: PMC5504629 DOI: 10.1039/c5sc02153g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/20/2015] [Indexed: 01/18/2023] Open
Abstract
Here we emphasise the importance of the dielectric environment on the electron transfer behavior in interfacial electrochemical systems. Through doping cobalt hexacyanide (Co(CN)63-) into single microcrystals of sodium chloride (NaCl), for the first time, we obtained the direct electrochemical behavior of Co(CN)63- which is hardly ever obtained in either aqueous or conventional nonaqueous solutions. DFT calculations elucidate that, as the Co(CN)63- anions occupy the lattice units of NaCl65- in the NaCl microcrystal, the redox energy barrier of Co(CN)63-/4- is decreased dramatically due to the low dielectric constant of NaCl. Meanwhile, the low-spin Co(CN)64- anions are stabilized in the lattices of the NaCl microcrystal. The results also show that the NaCl microcrystal is a potential solvent for solid-state electrochemistry at ambient temperature.
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Affiliation(s)
- Di Huang
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
| | - Yiliang Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
| | - Ya-Qiong Su
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
| | - Jie Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
| | - Lianhuan Han
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
| | - De-Yin Wu
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
| | - Zhong-Qun Tian
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
| | - Dongping Zhan
- State Key Laboratory of Physical Chemistry of Solid Surfaces , Department of Chemistry , College of Chemistry and Chemical Engineering , Xiamen University , 422 Siming South Road , Xiamen 361005 , China .
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112
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Krivenko AG, Komarova NS, Stenina EV, Sviridova LN, Mironovich KV, Shul’ga YM, Manzhos RA, Doronin SV, Krivchenko VA. Electrochemical modification of electrodes based on highly oriented carbon nanowalls. RUSS J ELECTROCHEM+ 2015. [DOI: 10.1134/s1023193515100079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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113
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Gearba RI, Mueller KM, Veneman PA, Holliday BJ, Chan CK, Stevenson KJ. Atom-scale covalent electrochemical modification of single-layer graphene on SiC substrates by diaryliodonium salts. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2015.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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114
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Kang M, Perry D, Kim YR, Colburn AW, Lazenby RA, Unwin PR. Time-Resolved Detection and Analysis of Single Nanoparticle Electrocatalytic Impacts. J Am Chem Soc 2015; 137:10902-5. [PMID: 26264494 DOI: 10.1021/jacs.5b05856] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is considerable interest in understanding the interaction and activity of single entities, such as (electro)catalytic nanoparticles (NPs), with (electrode) surfaces. Through the use of a high bandwidth, high signal/noise measurement system, NP impacts on an electrode surface are detected and analyzed in unprecedented detail, revealing considerable new mechanistic information on the process. Taking the electrocatalytic oxidation of H2O2 at ruthenium oxide (RuOx) NPs as an example, the rise time of current-time transients for NP impacts is consistent with a hydrodynamic trapping model for the arrival of a NP with a distance-dependent NP diffusion-coefficient. NP release from the electrode appears to be aided by propulsion from the electrocatalytic reaction at the NP. High-frequency NP impacts, orders of magnitude larger than can be accounted for by a single pass diffusive flux of NPs, are observed that indicate the repetitive trapping and release of an individual NP that has not been previously recognized. The experiments and models described could readily be applied to other systems and serve as a powerful platform for detailed analysis of NP impacts.
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Affiliation(s)
- Minkyung Kang
- Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K
| | - David Perry
- Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K
| | - Yang-Rae Kim
- Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K
| | - Alex W Colburn
- Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K
| | - Robert A Lazenby
- Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K
| | - Patrick R Unwin
- Department of Chemistry and ‡MOAC Doctoral Training Centre, University of Warwick , Coventry, CV4 7AL, U.K
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115
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Guo X, Zhou H, Zhang D, Fan T. Cyclic voltammogram on ridge/pore array architectured electrode inspired by butterfly-wings. PURE APPL CHEM 2015. [DOI: 10.1515/pac-2014-1201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractPorous architectured electrodes are intensely investigated for promoting electrochemical performance. Besides the high surface area, mass transport plays an irreplaceable role in the architecture assisting effect, which is, however, far beyond expression due to the complexity and irregularity of various electrode materials. Here, we took advantage of elaborate architectures from butterfly wings and obtained carbon electrode with ridge/pore array hierarchical architecture (ridge/pore-C) using a carbonizing-graphite coating method. A basic one-electron transfer process using the redox couple ferri/ferrocyanide as a benchmark under cyclic voltammetric conditions was conducted. The peak potential separation for ridge/pore-C was decreased by 117 mV compared to its non-architectured counterpart, with obvious enhancement of peak current density, indicating prominent beneficial impact on electrochemical responses. Further finite element simulation demonstrated the additional lateral diffusion within the ridge domain and partial thin layer diffusion within the pore array domain of ridge/pore-C, and simultaneously verified the experimental results. By constructing and investigating the well-organized porous architecture for affecting cyclic voltammogram, this work provides a prototype and cost-effective method for structural design of efficient electrodes by drawing inspiration from nature.
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Affiliation(s)
- Xingmei Guo
- 1State Key Lab of Metal Matrix Composites, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Han Zhou
- 1State Key Lab of Metal Matrix Composites, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Di Zhang
- 1State Key Lab of Metal Matrix Composites, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Tongxiang Fan
- 1State Key Lab of Metal Matrix Composites, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China
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116
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Doronin SV, Manzhos RA, Krivenko AG. EDL structure and peculiarities of ferricyanide cyclic voltammetry for silver deposits on gold. Electrochem commun 2015. [DOI: 10.1016/j.elecom.2015.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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117
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Ni B, Wang X. Face the Edges: Catalytic Active Sites of Nanomaterials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2015; 2:1500085. [PMID: 27980960 PMCID: PMC5115441 DOI: 10.1002/advs.201500085] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 04/19/2015] [Indexed: 05/07/2023]
Abstract
Edges are special sites in nanomaterials. The atoms residing on the edges have different environments compared to those in other parts of a nanomaterial and, therefore, they may have different properties. Here, recent progress in nanomaterial fields is summarized from the viewpoint of the edges. Typically, edge sites in MoS2 or metals, other than surface atoms, can perform as active centers for catalytic reactions, so the method to enhance performance lies in the optimization of the edge structures. The edges of multicomponent interfaces present even more possibilities to enhance the activities of nanomaterials. Nanoframes and ultrathin nanowires have similarities to conventional edges of nanoparticles, the application of which as catalysts can help to reduce the use of costly materials. Looking beyond this, the edge structures of graphene are also essential for their properties. In short, the edge structure can influence many properties of materials.
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Affiliation(s)
- Bing Ni
- Department of Chemistry Tsinghua University Beijing 100084 P. R. China
| | - Xun Wang
- Department of Chemistry Tsinghua University Beijing 100084 P. R. China
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118
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Velický M, Bissett MA, Toth PS, Patten HV, Worrall SD, Rodgers ANJ, Hill EW, Kinloch IA, Novoselov KS, Georgiou T, Britnell L, Dryfe RAW. Electron transfer kinetics on natural crystals of MoS2 and graphite. Phys Chem Chem Phys 2015; 17:17844-53. [PMID: 26088339 DOI: 10.1039/c5cp02490k] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Here, we evaluate the electrochemical performance of sparsely studied natural crystals of molybdenite and graphite, which have increasingly been used for fabrication of next generation monolayer molybdenum disulphide and graphene energy storage devices. Heterogeneous electron transfer kinetics of several redox mediators, including Fe(CN)6(3-/4-), Ru(NH3)6(3+/2+) and IrCl6(2-/3-) are determined using voltammetry in a micro-droplet cell. The kinetics on both materials are studied as a function of surface defectiveness, surface ageing, applied potential and illumination. We find that the basal planes of both natural MoS2 and graphite show significant electroactivity, but a large decrease in electron transfer kinetics is observed on atmosphere-aged surfaces in comparison to in situ freshly cleaved surfaces of both materials. This is attributed to surface oxidation and adsorption of airborne contaminants at the surface exposed to an ambient environment. In contrast to semimetallic graphite, the electrode kinetics on semiconducting MoS2 are strongly dependent on the surface illumination and applied potential. Furthermore, while visibly present defects/cracks do not significantly affect the response of graphite, the kinetics on MoS2 systematically accelerate with small increase in disorder. These findings have direct implications for use of MoS2 and graphene/graphite as electrode materials in electrochemistry-related applications.
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Affiliation(s)
- Matěj Velický
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
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119
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Güell AG, Cuharuc AS, Kim YR, Zhang G, Tan SY, Ebejer N, Unwin PR. Redox-dependent spatially resolved electrochemistry at graphene and graphite step edges. ACS NANO 2015; 9:3558-71. [PMID: 25758160 DOI: 10.1021/acsnano.5b00550] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The electrochemical (EC) behavior of mechanically exfoliated graphene and highly oriented pyrolytic graphite (HOPG) is studied at high spatial resolution in aqueous solutions using Ru(NH3)6(3+/2+) as a redox probe whose standard potential sits close to the intrinsic Fermi level of graphene and graphite. When scanning electrochemical cell microscopy (SECCM) data are coupled with that from complementary techniques (AFM, micro-Raman) applied to the same sample area, different time-dependent EC activity between the basal planes and step edges is revealed. In contrast, other redox couples (ferrocene derivatives) whose potential is further removed from the intrinsic Fermi level of graphene and graphite show uniform and high activity (close to diffusion-control). Macroscopic voltammetric measurements in different environments reveal that the time-dependent behavior after HOPG cleavage, peculiar to Ru(NH3)6(3+/2+), is not associated particularly with any surface contaminants but is reasonably attributed to the spontaneous delamination of the HOPG with time to create partially coupled graphene layers, further supported by conductive AFM measurements. This process has a major impact on the density of states of graphene and graphite edges, particularly at the intrinsic Fermi level to which Ru(NH3)6(3+/2+) is most sensitive. Through the use of an improved voltammetric mode of SECCM, we produce movies of potential-resolved and spatially resolved HOPG activity, revealing how enhanced activity at step edges is a subtle effect for Ru(NH3)6(3+/2+). These latter studies allow us to propose a microscopic model to interpret the EC response of graphene (basal plane and edges) and aged HOPG considering the nontrivial electronic band structure.
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Affiliation(s)
- Aleix G Güell
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Anatolii S Cuharuc
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Yang-Rae Kim
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Guohui Zhang
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Sze-yin Tan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Neil Ebejer
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Patrick R Unwin
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
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120
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Nioradze N, Chen R, Kurapati N, Khvataeva-Domanov A, Mabic S, Amemiya S. Organic Contamination of Highly Oriented Pyrolytic Graphite As Studied by Scanning Electrochemical Microscopy. Anal Chem 2015; 87:4836-43. [DOI: 10.1021/acs.analchem.5b00213] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Nikoloz Nioradze
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Ran Chen
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Niraja Kurapati
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | | | | | - Shigeru Amemiya
- Department
of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
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121
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Bandarenka AS, Ventosa E, Maljusch A, Masa J, Schuhmann W. Techniques and methodologies in modern electrocatalysis: evaluation of activity, selectivity and stability of catalytic materials. Analyst 2015; 139:1274-91. [PMID: 24418971 DOI: 10.1039/c3an01647a] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development and optimisation of materials that promote electrochemical reactions have recently attracted attention mainly due to the challenge of sustainable provision of renewable energy in the future. The need for better understanding and control of electrode-electrolyte interfaces where these reactions take place, however, implies the continuous need for development of efficient analytical techniques and methodologies capable of providing detailed information about the performance of electrocatalysts, especially in situ, under real operational conditions of electrochemical systems. During the past decade, significant efforts in the fields of electrocatalysis and (electro)analytical chemistry have resulted in the evolution of new powerful methods and approaches providing ever deeper and unique insight into complex and dynamic catalytic systems. The combination of various electrochemical and non-electrochemical methods as well as the application of quantum chemistry calculations has become a viable modern approach in the field. The focus of this critical review is primarily set on discussion of the most recent cutting-edge achievements in the development of analytical techniques and methodologies designed to evaluate three key constituents of the performance of electrocatalysts, namely, activity, selectivity and stability. Possible directions and future challenges in the design and elaboration of analytical methods for electrocatalytic research are outlined.
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Affiliation(s)
- Aliaksandr S Bandarenka
- Center for Electrochemical Sciences - CES, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
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122
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Miller TS, Macpherson JV, Unwin PR. Electrochemical activation of pristine single walled carbon nanotubes: impact on oxygen reduction and other surface sensitive redox processes. Phys Chem Chem Phys 2015; 16:9966-73. [PMID: 24472842 DOI: 10.1039/c3cp53717j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effect of systematic anodic pre-treatments of pristine single walled carbon nanotube (SWNT) forests on the electrochemical response towards a variety of redox processes is investigated. An experimental arrangement is adopted whereby a microcapillary containing the solution of interest and a quasi reference-counter electrode is brought into contact with a small portion of the forest to enable measurements on the surface before and after controlled anodic polarisation (AP). AP of the surface is found to both improve the voltammetric response (faster apparent heterogeneous electron transfer kinetics) of surface sensitive redox processes, such as Fe(2+/3+), and enhance the electrocatalytic response of the SWNTs towards oxygen reduction; the extent of which can be carefully controlled via the applied anodic potential. AP is expected to remove any trace organic (atmospheric) contaminants that may accumulate on the forest over extended periods as well as allowing the controlled introduction of defects, as confirmed by micro-Raman spectroscopy.
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Affiliation(s)
- Thomas S Miller
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
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123
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Petrii OA. Electrosynthesis of nanostructures and nanomaterials. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4438] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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124
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Gyan IO, Wojcik PM, Aston DE, McIlroy DN, Cheng IF. A Study of the Electrochemical Properties of a New Graphitic Material: GUITAR. ChemElectroChem 2015. [DOI: 10.1002/celc.201402433] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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125
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Lai SCS, Lazenby RA, Kirkman PM, Unwin PR. Nucleation, aggregative growth and detachment of metal nanoparticles during electrodeposition at electrode surfaces. Chem Sci 2015; 6:1126-1138. [PMID: 29560200 PMCID: PMC5811076 DOI: 10.1039/c4sc02792b] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 11/07/2014] [Indexed: 02/01/2023] Open
Abstract
The nucleation and growth of metal nanoparticles (NPs) on surfaces is of considerable interest with regard to creating functional interfaces with myriad applications. Yet, key features of these processes remain elusive and are undergoing revision. Here, the mechanism of the electrodeposition of silver on basal plane highly oriented pyrolytic graphite (HOPG) is investigated as a model system at a wide range of length scales, spanning electrochemical measurements from the macroscale to the nanoscale using scanning electrochemical cell microscopy (SECCM), a pipette-based approach. The macroscale measurements show that the nucleation process cannot be modelled as either truly instantaneous or progressive, and that step edge sites of HOPG do not play a dominant role in nucleation events compared to the HOPG basal plane, as has been widely proposed. Moreover, nucleation numbers extracted from electrochemical analysis do not match those determined by atomic force microscopy (AFM). The high time and spatial resolution of the nanoscale pipette set-up reveals individual nucleation and growth events at the graphite basal surface that are resolved and analysed in detail. Based on these results, corroborated with complementary microscopy measurements, we propose that a nucleation-aggregative growth-detachment mechanism is an important feature of the electrodeposition of silver NPs on HOPG. These findings have major implications for NP electrodeposition and for understanding electrochemical processes at graphitic materials generally.
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Affiliation(s)
- Stanley C S Lai
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , UK .
- MESA+ Institute for Nanotechnology , University of Twente , PO Box 217 , 7500 AE Enschede , The Netherlands .
| | - Robert A Lazenby
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , UK .
| | - Paul M Kirkman
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , UK .
| | - Patrick R Unwin
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry CV4 7AL , UK .
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126
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Functionalization and defunctionalization of single walled carbon nanotubes: Electrochemical and morphologic consequences. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2014.11.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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127
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Bosch-Navarro C, Laker ZPL, Rourke JP, Wilson NR. Reproducible, stable and fast electrochemical activity from easy to make graphene on copper electrodes. Phys Chem Chem Phys 2015; 17:29628-36. [DOI: 10.1039/c5cp04070a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemical vapor deposition grown graphene on copper is a fast, robust and easy to make electrochemical electrode. The electrochemical response is independent of the amount of basal-plane/edge-plane of graphene, and fully covered samples show no electrode fouling, giving a simple route to study graphene based electrodes.
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128
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Ren H, Zhang L, Li X, Li Y, Wu W, Li H. Interfacial structure and wetting properties of water droplets on graphene under a static electric field. Phys Chem Chem Phys 2015; 17:23460-7. [DOI: 10.1039/c5cp04205d] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The equilibrium water droplets present a hemispherical, a conical and an ordered cylindrical shape with the increase of external E-field intensity.
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Affiliation(s)
- Hongru Ren
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Leining Zhang
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Xiongying Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Yifan Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Weikang Wu
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
| | - Hui Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials
- Ministry of Education
- Shandong University
- Jinan 250061
- People's Republic of China
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129
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Zhang G, Cuharuc AS, Güell AG, Unwin PR. Electrochemistry at highly oriented pyrolytic graphite (HOPG): lower limit for the kinetics of outer-sphere redox processes and general implications for electron transfer models. Phys Chem Chem Phys 2015; 17:11827-38. [DOI: 10.1039/c5cp00383k] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electron transfer kinetics for outer-sphere redox couples is fast on the basal surface of highly oriented pyrolytic graphite (HOPG).
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Affiliation(s)
- Guohui Zhang
- Department of Chemistry
- University of Warwick
- Coventry
- UK
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130
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Zhong JH, Zhang J, Jin X, Liu JY, Li Q, Li MH, Cai W, Wu DY, Zhan D, Ren B. Quantitative Correlation between Defect Density and Heterogeneous Electron Transfer Rate of Single Layer Graphene. J Am Chem Soc 2014; 136:16609-17. [DOI: 10.1021/ja508965w] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Jin-Hui Zhong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Jie Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Xi Jin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Jun-Yang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Qiongyu Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Mao-Hua Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Weiwei Cai
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - De-Yin Wu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Dongping Zhan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
| | - Bin Ren
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, and ‡Department of Physics, Laboratory of Nanoscale Condensed Matter Physics, Xiamen University, Xiamen 361005, China
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131
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Velický M, Bradley DF, Cooper AJ, Hill EW, Kinloch IA, Mishchenko A, Novoselov KS, Patten HV, Toth PS, Valota AT, Worrall SD, Dryfe RAW. Electron transfer kinetics on mono- and multilayer graphene. ACS NANO 2014; 8:10089-10100. [PMID: 25290250 DOI: 10.1021/nn504298r] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Understanding of the electrochemical properties of graphene, especially the electron transfer kinetics of a redox reaction between the graphene surface and a molecule, in comparison to graphite or other carbon-based materials, is essential for its potential in energy conversion and storage to be realized. Here we use voltammetric determination of the electron transfer rate for three redox mediators, ferricyanide, hexaammineruthenium, and hexachloroiridate (Fe(CN)(6)(3-), Ru(NH3)(6)(3+), and IrCl(6)(2-), respectively), to measure the reactivity of graphene samples prepared by mechanical exfoliation of natural graphite. Electron transfer rates are measured for varied number of graphene layers (1 to ca. 1000 layers) using microscopic droplets. The basal planes of mono- and multilayer graphene, supported on an insulating Si/SiO(2) substrate, exhibit significant electron transfer activity and changes in kinetics are observed for all three mediators. No significant trend in kinetics with flake thickness is discernible for each mediator; however, a large variation in kinetics is observed across the basal plane of the same flakes, indicating that local surface conditions affect the electrochemical performance. This is confirmed by in situ graphite exfoliation, which reveals significant deterioration of initially, near-reversible kinetics for Ru(NH3)(6)(3+) when comparing the atmosphere-aged and freshly exfoliated graphite surfaces.
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Affiliation(s)
- Matěj Velický
- School of Chemistry, §School of Computer Science, ∥School of Materials, ⊥School of Physics and Astronomy, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
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132
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Stevenson KJ, Veneman PA, Gearba RI, Mueller KM, Holliday BJ, Ohta T, Chan CK. Controlled covalent modification of epitaxial single layer graphene on 6H-SiC (0001) with aryliodonium salts using electrochemical methods. Faraday Discuss 2014; 172:273-91. [DOI: 10.1039/c4fd00038b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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133
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Ritzert NL, Li W, Tan C, Rodríguez-Calero GG, Rodríguez-López J, Hernández-Burgos K, Conte S, Parks JJ, Ralph DC, Abruña HD. Single layer graphene as an electrochemical platform. Faraday Discuss 2014; 172:27-45. [DOI: 10.1039/c4fd00060a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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134
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Zhang G, Kirkman PM, Patel AN, Cuharuc AS, McKelvey K, Unwin PR. Molecular Functionalization of Graphite Surfaces: Basal Plane versus Step Edge Electrochemical Activity. J Am Chem Soc 2014; 136:11444-51. [DOI: 10.1021/ja505266d] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Guohui Zhang
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Paul M. Kirkman
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Anisha N. Patel
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Anatolii S. Cuharuc
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Kim McKelvey
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Patrick R. Unwin
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
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135
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Simonov AN, Morris GP, Mashkina EA, Bethwaite B, Gillow K, Baker RE, Gavaghan DJ, Bond AM. Inappropriate Use of the Quasi-Reversible Electrode Kinetic Model in Simulation-Experiment Comparisons of Voltammetric Processes That Approach the Reversible Limit. Anal Chem 2014; 86:8408-17. [DOI: 10.1021/ac5019952] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Graham P. Morris
- Mathematical
Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, United Kingdom
| | - Elena A. Mashkina
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Blair Bethwaite
- Monash
eResearch Centre, Monash University, Clayton, Victoria 3800, Australia
| | - Kathryn Gillow
- Mathematical
Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, United Kingdom
| | - Ruth E. Baker
- Mathematical
Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, United Kingdom
| | - David J. Gavaghan
- Department
of Computer Science, University of Oxford, Wolfson Building, Parks Road, Oxford, OX1 3QD, United Kingdom
| | - Alan M. Bond
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
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136
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Pyrene-wired antibodies on highly oriented pyrolytic graphite as a label-free impedance biosensor for the sepsis biomarker procalcitonin. J Solid State Electrochem 2014. [DOI: 10.1007/s10008-014-2588-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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137
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Wain AJ, Pollard AJ, Richter C. High-Resolution Electrochemical and Topographical Imaging Using Batch-Fabricated Cantilever Probes. Anal Chem 2014; 86:5143-9. [DOI: 10.1021/ac500946v] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Andrew J. Wain
- National Physical Laboratory, Hampton Road, Teddington, TW11 0LW United Kingdom
| | - Andrew J. Pollard
- National Physical Laboratory, Hampton Road, Teddington, TW11 0LW United Kingdom
| | - Christoph Richter
- NanoWorld Services GmbH, Schottkystraße
10, Erlangen, Bavaria 91058, Germany
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138
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Kleijn SEF, Lai SCS, Koper MTM, Unwin PR. Electrochemistry of Nanoparticles. Angew Chem Int Ed Engl 2014; 53:3558-86. [DOI: 10.1002/anie.201306828] [Citation(s) in RCA: 304] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Indexed: 01/01/2023]
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139
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140
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Yuan W, Zhou Y, Li Y, Li C, Peng H, Zhang J, Liu Z, Dai L, Shi G. The edge- and basal-plane-specific electrochemistry of a single-layer graphene sheet. Sci Rep 2014; 3:2248. [PMID: 23896697 PMCID: PMC3727060 DOI: 10.1038/srep02248] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 07/04/2013] [Indexed: 12/24/2022] Open
Abstract
Graphene has a unique atom-thick two-dimensional structure and excellent properties, making it attractive for a variety of electrochemical applications, including electrosynthesis, electrochemical sensors or electrocatalysis, and energy conversion and storage. However, the electrochemistry of single-layer graphene has not yet been well understood, possibly due to the technical difficulties in handling individual graphene sheet. Here, we report the electrochemical behavior at single-layer graphene-based electrodes, comparing the basal plane of graphene to its edge. The graphene edge showed 4 orders of magnitude higher specific capacitance, much faster electron transfer rate and stronger electrocatalytic activity than those of graphene basal plane. A convergent diffusion effect was observed at the sub-nanometer thick graphene edge-electrode to accelerate the electrochemical reactions. Coupling with the high conductivity of a high-quality graphene basal plane, graphene edge is an ideal electrode for electrocatalysis and for the storage of capacitive charges.
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Affiliation(s)
- Wenjing Yuan
- Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China
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141
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Güell AG, Meadows KE, Dudin PV, Ebejer N, Byers JC, Macpherson JV, Unwin PR. Selection, characterisation and mapping of complex electrochemical processes at individual single-walled carbon nanotubes: the case of serotonin oxidation. Faraday Discuss 2014; 172:439-55. [DOI: 10.1039/c4fd00054d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The electrochemical (EC) oxidation of the neurotransmitter, serotonin, at individual single-walled carbon nanotubes (SWNTs) is investigated at high resolution using a novel platform that combines flow-aligned SWNTs with atomic force microscopy, Raman microscopy, electronic conductance measurements, individual SWNT electrochemistry and high-resolution scanning electrochemical cell microscopy (SECCM). SECCM has been used to visualise the EC activity along side-wall sections of metallic SWNTs to assess the extent to which side-walls promote the electrochemistry of this complex multi-step process. Uniform and high EC activity is observed that is consistent with significant reaction at the side-wall, rather than electrochemistry being driven by defects alone. By scanning forward and reverse (trace and retrace) over the same region of a SWNT, it is also possible to assess any blocking of EC activity by serotonin oxidation reaction products. At a physiologically relevant concentration (5 μM), there is no detectable blocking of SWNTs, which can be attributed, at least in part, to the high diffusion rate to an individual, isolated SWNT in the SECCM format. At higher serotonin concentration (2 mM), oligomer formation from oxidation products is much more significant and major blocking of the EC process is observed from line profiles recorded as the SECCM meniscus moves over an SWNT. The SECCM line profile morphology is shown to be highly diagnostic of whether blocking occurs during EC processes. The studies herein add to a growing body of evidence that various EC processes at SWNTs, from simple outer sphere redox reactions to complex multi-step processes, occur readily at pristine SWNTs. The platform described is of general applicability to various types of nanostructures and nanowires.
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Affiliation(s)
- Aleix G. Güell
- Department of Chemistry
- University of Warwick
- Coventry, United Kingdom
| | - Katherine E. Meadows
- Department of Chemistry
- University of Warwick
- Coventry, United Kingdom
- Molecular Organisation and Assembly in Cells Doctoral Training Centre
- University of Warwick
| | - Petr V. Dudin
- Department of Chemistry
- University of Warwick
- Coventry, United Kingdom
| | - Neil Ebejer
- Department of Chemistry
- University of Warwick
- Coventry, United Kingdom
| | - Joshua C. Byers
- Department of Chemistry
- University of Warwick
- Coventry, United Kingdom
| | | | - Patrick R. Unwin
- Department of Chemistry
- University of Warwick
- Coventry, United Kingdom
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142
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Anne A, Bahri MA, Chovin A, Demaille C, Taofifenua C. Probing the conformation and 2D-distribution of pyrene-terminated redox-labeled poly(ethylene glycol) chains end-adsorbed on HOPG using cyclic voltammetry and atomic force electrochemical microscopy. Phys Chem Chem Phys 2014; 16:4642-52. [DOI: 10.1039/c3cp54720e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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143
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Toth PS, Valota AT, Velický M, Kinloch IA, Novoselov KS, Hill EW, Dryfe RAW. Electrochemistry in a drop: a study of the electrochemical behaviour of mechanically exfoliated graphene on photoresist coated silicon substrate. Chem Sci 2014. [DOI: 10.1039/c3sc52026a] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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144
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Chen S, Liu Y, Chen J. Heterogeneous electron transfer at nanoscopic electrodes: importance of electronic structures and electric double layers. Chem Soc Rev 2014; 43:5372-86. [DOI: 10.1039/c4cs00087k] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Recent insights into the nanoscopic electrode size and structure effects on heterogeneous ET kinetics are presented.
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Affiliation(s)
- Shengli Chen
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)
- Hubei Key Laboratory of Electrochemical Power Sources
- Department of Chemistry
- Wuhan University
- Wuhan 430072, China
| | - Yuwen Liu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)
- Hubei Key Laboratory of Electrochemical Power Sources
- Department of Chemistry
- Wuhan University
- Wuhan 430072, China
| | - Junxiang Chen
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)
- Hubei Key Laboratory of Electrochemical Power Sources
- Department of Chemistry
- Wuhan University
- Wuhan 430072, China
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145
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Juarez MF, Fuentes S, Soldano GJ, Avalle L, Santos E. Spontaneous formation of metallic nanostructures on highly oriented pyrolytic graphite (HOPG): an ab initio and experimental study. Faraday Discuss 2014; 172:327-47. [DOI: 10.1039/c4fd00047a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have investigated the decoration of step-edges of HOPG by Ag, Au and Pt using experimental and theoretical approaches. Metallic nanowires can be formed on bare or functionalized step-edges. Energy dispersion analysis indicates the presence of oxygenated groups. The experiments showed that nanowires can be obtained with the three metals along the step-edges, but the shapes and morphologies are very different. We have found that the interaction between the metal wires and the carbon follows the sequence: Pt > Au > Ag. The electronic redistribution between the atoms participating in the bond between the metallic nanowire and the step-edges shows a complicated pattern. The density of electronic states projected on the different atoms indicates that there are different orbitals participating in the bonds.
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Affiliation(s)
- Maria F. Juarez
- Institute of Theoretical Chemistry
- Ulm University
- D-89069 Ulm, Germany
| | - Silvina Fuentes
- Facultad de Ciencias Exactas y Naturales
- Universidad Nacional de Catamarca
- Catamarca, Argentina
- Instituto de Fîsica Enrique Gaviola (IFEG-CONICET)
- Facultad de Matemática
| | - Germán J. Soldano
- Institute of Theoretical Chemistry
- Ulm University
- D-89069 Ulm, Germany
| | - Lucia Avalle
- Facultad de Ciencias Exactas y Naturales
- Universidad Nacional de Catamarca
- Catamarca, Argentina
- Instituto de Fîsica Enrique Gaviola (IFEG-CONICET)
- Facultad de Matemática
| | - Elizabeth Santos
- Institute of Theoretical Chemistry
- Ulm University
- D-89069 Ulm, Germany
- Instituto de Fîsica Enrique Gaviola (IFEG-CONICET)
- Facultad de Matemática
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146
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Abstract
This contribution provides a personal overview and summary of Faraday Discussion 172 on “Carbon in Electrochemistry”, covering some of the key points made at the meeting within the broader context of other recent developments on carbon materials for electrochemical applications. Although carbon electrodes have a long history of use in electrochemistry, methods and techniques are only just becoming available that can test long-established models and identify key features for further exploration. This Discussion has highlighted the need for a better understanding of the impact of surface structure, defects, local density of electronic states, and surface functionality and contamination, in order to advance fundamental knowledge of various electrochemical processes and phenomena at carbon electrodes. These developments cut across important materials such as graphene, carbon nanotubes, conducting diamond and high surface area carbon materials. With more detailed pictures of structural and electronic controls of electrochemistry at carbon electrodes (and electrodes generally), will come rational advances in various technological applications, from sensors to energy technology (particularly batteries, supercapacitors and fuel cells), that have been well-illustrated at this Discussion.
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Affiliation(s)
- Patrick R. Unwin
- Department of Chemistry
- University of Warwick
- Coventry CV4 7AL, UK
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147
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Lounasvuori MM, Rosillo-Lopez M, Salzmann CG, Caruana DJ, Holt KB. Electrochemical characterisation of graphene nanoflakes with functionalised edges. Faraday Discuss 2014; 172:293-310. [DOI: 10.1039/c4fd00034j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Graphene nanoflakes (GNF) of diameter ca. 30 nm and edge-terminated with carboxylic acid (COOH) or amide functionalities were characterised electrochemically after drop-coating onto a boron-doped diamond (BDD) electrode. In the presence of the outer-sphere redox probe ferrocenemethanol there was no discernible difference in electrochemical response between the clean BDD and GNF-modified electrodes. When ferricyanide or hydroquinone were used as redox probes there was a marked difference in response at the electrode modified with COOH-terminated GNF in comparison to the unmodified BDD and amide-terminated GNF electrode. The response of the COOH-terminated GNF electrode was highly pH dependent, with the most dramatic differences in response noted at pH < 8. This pH range coincides with partial protonation of the carboxylic acid groups as determined by titration. The acid edge groups occupy a range of bonding environments and are observed to undergo deprotonation over a pH range ca. 3.7 to 8.3. The protonation state of the GNF influences the oxidation mechanism of hydroquinone and in particular the number of solution protons involved in the reaction mechanism. The voltammetric response of ferricyanide is very inhibited by the presence of COOH-terminated GNF at pH < 8, especially in low ionic strength solution. While the protonation state of the GNF is clearly a major factor in the observed response, the exact role of the acid group in the redox process has not been firmly established. It may be that the ferricyanide species is unstable in the solution environment surrounding the GNF, where dynamic protonation equilibria are at play, perhaps through disruption to ion pairing.
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Affiliation(s)
| | | | | | - Daren J. Caruana
- Department of Chemistry
- University College London
- London WC1H 0AJ, United Kingdom
| | - Katherine B. Holt
- Department of Chemistry
- University College London
- London WC1H 0AJ, United Kingdom
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148
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Patten HV, Velický M, Clark N, Muryn CA, Kinloch IA, Dryfe RAW. Electrochemistry of well-defined graphene samples: role of contaminants. Faraday Discuss 2014; 172:261-72. [DOI: 10.1039/c4fd00064a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We report the electrochemical characterisation of well-defined graphene samples, prepared by mechanical exfoliation. Mechanical exfoliation is the method of choice for high purity graphene samples, despite the inherent complexity of the approach and the small scale of the resultant flakes. However, one important, yet presently unclear area, is the role of adsorbates such as processing residue, on the properties of the graphene layer. We report high resolution microscopic and electrochemical characterisation of a variety of poly(methyl methacrylate) (PMMA) transferred graphene samples, with the explicit aim of investigating the relationship between electrochemical activity and sample purity.
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Affiliation(s)
- Hollie V. Patten
- School of Chemistry
- University of Manchester
- Manchester M13 9PL, UK
| | - Matěj Velický
- School of Chemistry
- University of Manchester
- Manchester M13 9PL, UK
| | - Nick Clark
- School of Materials
- University of Manchester
- Manchester M13 9PL, UK
- Centre for Mesoscience and Nanotechnology
- University of Manchester
| | - Christopher A. Muryn
- School of Chemistry
- University of Manchester
- Manchester M13 9PL, UK
- Photon Science Institute
- University of Manchester
| | - Ian A. Kinloch
- School of Materials
- University of Manchester
- Manchester M13 9PL, UK
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149
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Patel AN, Tan SY, Miller TS, Macpherson JV, Unwin PR. Comparison and Reappraisal of Carbon Electrodes for the Voltammetric Detection of Dopamine. Anal Chem 2013; 85:11755-64. [DOI: 10.1021/ac401969q] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Anisha N. Patel
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Sze-yin Tan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Thomas S. Miller
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | | | - Patrick R. Unwin
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
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150
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Morris GP, Simonov AN, Mashkina EA, Bordas R, Gillow K, Baker RE, Gavaghan DJ, Bond AM. A Comparison of Fully Automated Methods of Data Analysis and Computer Assisted Heuristic Methods in an Electrode Kinetic Study of the Pathologically Variable [Fe(CN)6]3–/4– Process by AC Voltammetry. Anal Chem 2013; 85:11780-7. [DOI: 10.1021/ac4022105] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Graham P. Morris
- Mathematical
Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter,
Woodstock Road, Oxford, OX2 6GG, United Kingdom
| | | | - Elena A. Mashkina
- School
of Chemistry, Monash University, Clayton, Vic. 3800, Australia
| | - Rafel Bordas
- Department
of Computer Science, University of Oxford, Wolfson Building, Parks Road, Oxford, OX1 3QD, United Kingdom
| | - Kathryn Gillow
- Mathematical
Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter,
Woodstock Road, Oxford, OX2 6GG, United Kingdom
| | - Ruth E. Baker
- Mathematical
Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter,
Woodstock Road, Oxford, OX2 6GG, United Kingdom
| | - David J. Gavaghan
- Department
of Computer Science, University of Oxford, Wolfson Building, Parks Road, Oxford, OX1 3QD, United Kingdom
| | - Alan M. Bond
- School
of Chemistry, Monash University, Clayton, Vic. 3800, Australia
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