Quartz Crystal Microbalance Technique Research Articles

Application of the quartz crystal microbalance technique in corrosion studies. A review

Application of the quartz crystal microbalance technique in corrosion studies. A review

Investigation of environmentally volatile pollutants sensing using pillar[5]arene-based macrocycle Langmuir–Blodgett film

This study presented that a novel pillar[5]arene-appended salicylaldehyde (P5-S) was structured in a suitable cavity, which plays an important role in macrocyclic host–guest interactions. P5-S thin films were fabricated and characterized via Langmuir–Blodgett (LB), UV–vis spectrophotometer and quartz crystal microbalance (QCM) techniques, respectively. A QCM sensor deposited with an LB thin film of P5-S macrocyclic molecule was used as a sensitive material for the detection of aliphatic chlorinated hydrocarbons and aromatic hydrocarbons such as carbon tetrachloride, chloroform, dichloromethane and benzene, toluene and m-xylene vapors, respectively. These harmful organic vapors are a source of danger to the environment and are a group of important environmental pollutants. Similar tests were performed with surface plasmon resonance (SPR) technique, and SPR kinetic results were obtained in good agreement with QCM kinetic results. Also, the sensitivity and detection performance of the P5-S QCM chemical sensor to six different pollutants were determined.

Improvement of sensing properties for polymer based gas sensors via host–guest principles

This study aimed at improving the sensing properties of polymer-based gas sensors by controlling the surface adsorption. For this purpose, a polymer was produced as a Langmuir–Blodgett (LB) thin film chemical gas sensor element. The polymer material used was characterized by FTIR, 1H and 13C NMR analyses. All LB thin film layers were characterized by UV–Vis spectroscopy, scanning electron microscopy (SEM), quartz crystal microbalance (QCM) and atomic force microscopy (AFM) techniques. The polymeric chemical sensor was exposed to four different harmful organic vapours using QCM. The diffusion coefficients were calculated for each organic vapour using the short time approximation of the Fick’s second diffusion law. The results showed that the response of the polymeric LB films to the harmful vapours was large, fast and reversible and the diffusion coefficients were found to increase in the order dichloromethane, chloroform, benzene and toluene at room temperature.

Erosion of iron-tungsten model films by deuterium ion irradiation: a benchmark for TRI3DYN

The state-of-the-art 3D version of the Monte Carlo sputtering code TRI3DYN was benchmarked with experimental results obtained for iron-tungsten model films. The data which served for comparison concerned: (a) the mass removal rate for Fe-W films (with W) by prolonged deuterium ion bombardment at measured with the quartz crystal microbalance (QCM) technique as a function of ion fluence (up to a total fluence of ); (b) the change in surface morphology as measured by atomic force microscopy, and; (c) the change in elemental surface compositions as determined by different surface analytical techniques. Our benchmarking studies show that the code TRI3DYN is able to predict the outcome of the experiments, if the information about the initial surface morphology and elemental depth profile measurements of the sample are taken into account. It is not only the dynamical behaviour of the erosion yield with ion fluence that can be reproduced, but also the emerging surface pattern and the observed tungsten enrichment at the structured surface. The code provides a first insight into the reasons for the high influence of surface roughness at the scale on the sputtering behaviour of the plasma facing components (PFCs).

Characterization of Plukenetia volubilis L. fatty acid-based alkyd resins

Fatty acid-based alkyd resins prepared with different amounts of glycerol and pentaerythritol were characterized. Sacha inchi oil and linseed oil (comparative purposes) were used as fatty acids’ sources. FT-IR and 1H NMR spectroscopy were done for alkyd structural verification. Alkyd resins were evaluated through physico-chemical (colour, density, viscosity) and thermal characterization. Film coating performance (drying, hardness, chemical resistance) was also studied. The oxidative crosslinking time tendency was corroborated by the quartz crystal microbalance (QCM) technique. Alkyd resins obtained with fatty acids from sacha inchi and linseed oils had similar properties. Results indicated that lighter resins can be obtained from sacha inchi oil, whereas pentaerythritol increases viscosity and thermal stability, and retards drying time of fatty-acid based alkyd resins.

Microscopic Insight into Kinetics of Inorganic Scale Deposition during Smart Water Injection Using Dynamic Quartz Crystal Microbalance and Molecular Dynamics Simulation

Inorganic scale deposition has been found to affect many industrial processes, including water injection into the oil reservoirs. The incompatibility of high sulfate ion content of seawater with formation water containing calcium ion results in formation damage and production decline. In this study, several simultaneous techniques are utilized for qualitative and quantitative analysis of calcium sulfate scale to get more insight into the damage of formation during smart water flooding at micro and Nano scales. In the experimental section, calcium sulfate deposition due to the mixing of the formation water and seawater samples was investigated using the dynamic quartz crystal microbalance technique (DQCM). The effect of sulfate and magnesium ions existing in the seawater on the amount of calcium sulfate deposition were studied, individually. The results showed that the sulfate concentration of seawater could significantly change the mass deposition in a specific range. Also, at an optimal concentration of ...

Investigation of the electrochemical behaviour of lead dioxide in aqueous sulfuric acid solutions by using the in situ EQCM technique

The charge-discharge characteristics and the aging mechanism of PbO2 layers in contact with sulfuric acid solutions of different concentrations (1.5–5.0 M) were studied by using combined cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM) techniques. For this purpose, thick lead dioxide layers were electrodeposited on gold substrate from aqueous solutions of Pb(NO3)2 dissolved in nitric acid. Based on the electrochemical and the mass change responses, it was found that in more concentrated solutions of H2SO4, the main reduction reaction was the transformation of lead dioxide to lead sulfate. However, in less concentrated sulfuric acid media, the transformation of lead dioxide to lead(II) ion became the main reaction. These Pb2+ ions transformed into lead sulfate crystals later by a chemical reaction. Because the electrochemical oxidation of lead sulfate is less favourable in sulfuric acid medium of higher concentrations, thus, PbO2 layers cannot be tested by continuous cyclization, which is necessary to study their aging parameters. Therefore, a delay step before each cyclic voltammogram was applied while the non-conductive lead sulfate dissolves or alternatively, by applying a pre-oxidation step prior to each cyclic voltammetry experiment to produce electrochemically significant amount of lead dioxide which can be reduced during the following negative potential sweep.

Sorption and Diffusion of Methanol and Ethanol in Macroporous Sulfonic Resin Amberlyst 15

The sorption and diffusion of methanol and ethanol on Amberlyst 15 were studied by the quartz crystal microbalance technique in the temperature range of 20-120°C at relative pressure p/ps < 0.04. The heats of sorption (∆H) and the activation energy of diffusion (Ea) of methanol and ethanol were determined from the temperature dependence of the Henry constant and the effective diffusion coefficient of the alcohols in the gel phase of Amberlyst 15. The proximity of the ∆H and Ea values for each of the sorbates indicates that mass transfer within the Amberlyst 15 gel phase takes place by a sorption–desorption mechanism.

PHOSPHONIC ACID MONOLAYERS FOR CORROSION PROTECTION OF COPPER: EQCM AND EIS INVESTIGATIONS

Preparation, characterization and application of protective phosphonic acid monolayers formed by 1-Aminohexyl phosphonic acid (AHP), 1,4-butanediphosphonic acid (BDPA), 1-amino-1,3-dimethylbutyl phosphonic acid (ADBP) on copper surface as anticorrosive self-assembled molecular monolayers (SAMs) have been investigated by atomic force microscopy (AFM) analysis, electrochemical impedance spectroscopy (EIS) and in situ electrochemical quartz crystal microbalance (EQCM) techniques. Film formation and growth were monitored by EQCM and the step-by-step construction of monolayer was investigated through measurement of the frequency change, which corresponds to mass change due to the adsorption of molecules. Observed increase in electrode mass suggests that SAMs formed on copper surface by the adsorption of phosphonic acids. Results clearly demonstrate that adsorbed amounts of phosphonic acids were strongly influenced by immersion time and molecular structure. Quantum chemical calculations were performed by semi-empirical PM6 method, in order to explain the relationship between molecular structure and adsorption mechanism. Quantum chemical parameters of phosphonic acids propound that adsorption of molecules on copper surface has a chemical mechanism. Corrosion protection ability of SAMs against the acidic corrosion of copper has been evaluated in 0.1[Formula: see text]M H2SO4 solution. It was found that phosphonic acid SAMs act as protective barrier and the protection efficiencies increased in the following order: [Formula: see text].

Characterization of stratified EPS and their role in the initial adhesion of anammox consortia

Anammox bacteria tend to self-aggregate, and biofilm-based anammox processes are widely used as sustainable alternative methods for nitrogen removal from wastewater. However, the mechanism for the initial adhesion of anammox bacteria remains unclear. In this work, extracellular polymeric substances (EPS) were extracted separately from anammox granules and then characterized by multi-methods. The adhesion properties of anammox consortia to biotic and abiotic surfaces were examined separately before and after the extraction of three stratified EPS, using aggregation assays and a quartz crystal microbalance technique with dissipation monitoring, respectively. The extraction of each of the three stratified EPS gradually increased the initial aggregation of anammox consortia from 77.6 ± 3.0% to 85.2 ± 2.6%. Fourier transform infrared spectrometry confirmed that the aggregation of anammox consortia depended largely on the interactions between functional groups on the cell surfaces. All three stratified EPS had positive effects on the initial adhesion rate and mass of anammox consortia to abiotic surfaces. More importantly, the structure of the adhered layer was more compact before the extraction of each of the three stratified EPS. We therefore hypothesized that the initial adhesion among anammox consortia was due to the ability of the anammox bacteria to express adhesion molecules on the bacterial surfaces and that the three stratified EPS were excreted to adhere inert particulates and form a compact biofilm structure. This study clarifies the role of stratified EPS on the initial formation of anammox biofilms and provides a theoretical basis for accelerating the formation of anammox biofilms.

Quartz Crystal Microbalance Detection of Aflatoxin B1 by Self-Assembled Monolayer Technique

Background: New biosensor techniques allowing detection of low concentrated substances show a great variety nowadays. The construction of a system with modified quartz as a part of a Quartz Crystal Microbalance (QCM) techniques helps the detection and confirmation of low toxin concentrations in a sample. Objective: The study aims to allow the application of methods for preparation and modification of the gold surface of piezoelectric crystal for detection of aflatoxin B1(AFB1) in the concentration range 0.2 - 2.0 µg/L by QCM technique (quartz - crystal microbalance). Methods: The procedure for the preparation of quartz crystal sensors for experimental purposes was performed. The quartz surface was activated and covered with self-assembled monolayer to immobilize antibody (rabbit anti-aflatoxin B1) for the detection of antigen - antibody reaction. Results: The G” corresponds to viscous properties of the material, during applied deformation of the material in the presence of different concentrations, which revealed in the sensitivity of the used resonator. Conclusion: Detection of toxic pollutants may be achieved via QCM methods, ultrasound resonator and piezoelectric quartz techniques for measurement. These techniques allow detection of significantly low concentrations of toxic pollutants, in particular, AFB1, compared to analysis with direct and indirect ELISA immunoassays.

Chemical Sensor Properties and Mathematical Modeling of Graphene Oxide Langmuir-Blodgett Thin Films

Graphene oxide (GO) Langmuir–Blodgett (LB) thin films were prepared to use as chemical sensor element. The properties of GO LB thin film layers were characterized via Quartz crystal microbalance (QCM) method. Selectivity of the sensor to various organic vapors was investigated by surface plasmon resonance (SPR) and QCM techniques. Fick’s equations were used for calculating the diffusion coefficients ( D ) values of organic vapors. It was observed that chemical gas sensing characteristics of the GO film sensor shows a large response to some hazardous organic vapors. Then, by using experimental measurements that obtained during this process, NARX-ANN-based mathematical model of frequency shift of the quartz resonator was designed. The results of NARX-ANN verify the efficiency of the designed model.

Evaporative Crystallization of Dibenzoylmethanato Boron Difluoride Probed by Time-resolved Quartz Crystal Microbalance Responses with Fluorescence Changes

We have studied the evaporative crystallization of dibenzoylmethanato boron difluoride complex (BF2DBM) using the quartz crystal microbalance (QCM) technique and based on fluorescence changes. The ...

Diffusion of C6 cyclic hydrocarbons in ZSM-5 zeolite: From single nanocrystal to packed pellet

Abstract Transport of cyclohexane and benzene in ZSM-5 zeolite was studied. The intracrystalline diffusion in zeolite crystals was investigated using quartz crystal microbalance technique. The mass transfer process in packed zeolite pellet was studied by the diffusion cell method. It is demonstrated that the mass transfer kinetics for both diffusing agents follows the second Fick's law of diffusion in either single zeolite crystal or zeolite pellet. Changing the spatial scale from single zeolite crystal (order of nm) to a packed zeolite pellet (order of mm) results in increasing the diffusion coefficient from 10−16 m2/s to 10−10 m2/s.

Rational Design of Nanoporous MoS2 /VS2 Heteroarchitecture for Ultrahigh Performance Ammonia Sensors.

2D transition metal dichalcogenides (TMDs) have received widespread interest by virtue of their excellent electrical, optical, and electrochemical characteristics. Recent studies on TMDs have revealed their versatile utilization as electrocatalysts, supercapacitors, battery materials, and sensors, etc. In this study, MoS2 nanosheets are successfully assembled on the porous VS2 (P-VS2 ) scaffold to form a MoS2 /VS2 heterostructure. Their gas-sensing features, such as sensitivity and selectivity, are investigated by using a quartz crystal microbalance (QCM) technique. The QCM results and density functional theory (DFT) calculations reveal the impressive affinity of the MoS2 /VS2 heterostructure sensor toward ammonia with a higher adsorption uptake than the pristine MoS2 or P-VS2 sensor. Furthermore, the adsorption kinetics of the MoS2 /VS2 heterostructure sensor toward ammonia follow the pseudo-first-order kinetics model. The excellent sensing features of the MoS2 /VS2 heterostructure render it attractive for high-performance ammonia sensors in diverse applications.

Effect of Water Incorporation on the Lubrication Characteristics of Synthetic Oils

Deterioration of the lubricant performance of oils due to water incorporation is a major cause of failure during prolonged operation of mechanical assemblies. However, early indication of lubricant failure is challenging. In this work, a quartz crystal microbalance (QCM) technique was used to sense changes in oil characteristics and degradation upon water incorporation. The results obtained during runs at different temperatures indicate stronger signs of oil degradation with larger amount of water mixed in it. The observations on the lubrication performance of water-containing lubricants were confirmed by evaluating the effect of water incorporation on the tribological performance of steel surfaces immersed in synthetic oil. Macroscale tribological analysis indicated an increase in friction and wear of sliding steel components lubricated with water-containing oil after longer durations of tests. The results of this study provide new insights into how early signs of oil degradation can be sensed using the QCM technique toward minimizing the potential negative impact of such changes on the lubrication characteristics of oils.

Advanced Nanoporous Material–Based QCM Devices: A New Horizon of Interfacial Mass Sensing Technology

AbstractMass interfacial processes have been considered as one of the crucial factors supporting fundamental research. Due to the low cost and conceptual simplicity, significant advancements have been achieved in the development of methodologies based on piezoelectric devices for in situ determination of mass changes on the surfaces of deposited materials under various conditions. The introduction of nanomaterials for designing sensors and monitoring systems becomes essential to create advanced detection systems for selective sensing of toxic analytes for environmental remediation. The integration of materials with predesignated nanostructures into sensor devices, such as surface acoustic wave (SAW), quartz crystal microbalance (QCM), and QCM with dissipation (QCM‐D) monitoring, has led to an immense progress in the sensing applications of toxic target analytes at the nanogram range. Here, an overview is introduced of recent advancement in the fabrication of piezoelectric devices for the interfacial mass sensing of targeted chemical vapors and ions through combination with nanoporous materials including mesoporous materials carbon‐based nanomaterials, metal–organic frameworks (MOFs), MOF‐derived nanoporous carbons, Prussian blue (PB) and its analogues (PBA), zeolites and related materials. Challenges and future prospect are also summarized by the advanced QCM technique associated with properties of nanostructured materials.

Vibrating Powders: Electrochemical Quartz Crystal Microbalance Measurement of Potential Dependent IrO2 and Pt/C Mass Changes for Reversal Tolerant PEMFC Anodes

Oxygen evolution reaction (OER) catalysts are used to protect carbon components of polymer electrolyte membrane fuel cell (PEMFC) anodes during transient fuel starvation conditions such as start-up/shut-down [1]. OER catalysts such as IrO2 or RuO2 promote the oxidation of water instead of the corrosion of carbon components [1, 2]. However, the conditions in a PEMFC during normal operation (ca. 0 V and low pH) can induce instability in these metal oxides. IrO2 in particular can form soluble Ir3+ species [3] that migrate across the membrane electrode assembly and deposit on the cathode causing poisoning of the oxygen reduction reaction (ORR) catalyst (typically Pt/C). Currently, OER catalysts for reversal tolerant anodes (RTAs) are investigated using prototype MEA single unit cell testing which is time consuming and expensive to perform [4]. Previously, our group investigated the dissolution of different IrO2 based powder catalysts using a potential stepping stress test. The dissolution of Ir3+ from this test was compared with reversal tolerance of a membrane electrode assembly fabricated using the same IrO2 catalyst [5]. To further investigate the potential dependent mass changes of IrO2 powder layers, we have devised a series of experiments (with potential cycling between 0.05 to 1.2, 1.4 and 1.6 V vs. RHE, 30 times each at 100 mV s-1 and 298 K) using the electrochemical quartz crystal microbalance (EQCM) technique. The EQCM uses a vibrating quartz crystal and measures its frequency (inversely proportional to crystal mass) as a function of potential. Our method was used to investigate a commercially available IrO2 powder (Alfa Aesar) heat treated in air at 350, 450 and 550 °C. This heat treatment improves durability while reducing OER activity [6]. The powders were deposited (24 μg cm-2) onto a gold EQCM crystal to investigate the dissolution behavior as a function of particle size, crystallinity and electrode potential. We observed that the frequency of the untreated IrO2 increased by ca. 80 Hz (-570 ng cm-2) during the initial polarization from 1.15 V to 0.05 V vs. RHE (Figure a). The electrolyte was tested for dissolved Ir by inductively coupled plasma mass spectrometry (ICP-MS) but it was below the detection limit. This suggests that the first cycle frequency increase is caused by decreased rigidity of the IrO2 particle aggregates. During subsequent cycles, the untreated IrO2 frequency profile was consistent with previous reports. Birss et al. reported the formation of an iridium oxo-hydroxide at low potentials which causes a mass decrease (frequency increase) when polarizing to from 0 to 1.0 V vs. RHE [7]. Conversely, the frequency of heat treated layers first decreases by ca. 70 Hz (500 ng cm-2) before increasing again when polarizing to from 0.05 to 1.6 V vs. RHE (Figure b). Over the course of 90 CV cycles, there was an increase in film mass from the formation of iridium oxo-hydroxide species; confirmed by XPS. A platinum on carbon catalyst (Pt/C) was added to the IrO2 powders and the same experiment was performed (Figure c and d). This produced a dramatic increase in frequency which corresponded to a mass increase larger than the total deposited mass. Therefore, this mass decrease cannot be caused by dissolution of Pt or carbon corrosion alone and is instead attributed to loss of adhesion and changes in the viscoelasticity of the Pt/C aggregates. [8] The main challenge to using EQCM for powder catalyst investigation is producing layers with consistent and repeatable frequency behavior. In this work, the IrO2 and Pt/C deposition conditions were tightly controlled and each experiment was repeated to ensure the consistency of the results. It can also be difficult to interpret results and various analytical techniques should be used to supplement the EQCM technique. Despite these drawbacks, EQCM is a rapid and powerful tool to learn about potential dependent reactions using a myriad of powder catalysts. Ralph TR, Hudson S, Wilkinson DP (2006) ECS Trans 1:67–84.Patterson TW, Darling RM (2006) Electrochem Solid-State Lett 9:A183–A185.Danilovic N, Subbaraman R, Chang K-C, et al (2014) J Phys Chem Lett 5:2474–2478.Makharia R, Kocha S, Yu P, et al (2006) ECS Trans 1:3–18.Moore CE, Eastcott J, Cimenti M, Kremliakova N, Gyenge EL (2019) J Power Sources 417:53-60da Silva GC, Perini N, Ticianelli EA (2017) App Cat B: Env 218 287–297.Birss VI, Elzanowska H, Gottesfeld S (1991) Journal of Electroanalytical Chemistry and Interfacial Electrochemistry 318:327–333.Lu S, Chung DDL (2013) Carbon 60:346–355. Figure 1

Effects of Native Solid Electrolyte Interphase Layer Formation of Cu Electrode on Lithium Electrodeposition/Dissolution Processes

Lithium has been extensively expected as one of the most ideal anode materials of the next generation lithium-based batteries such as a lithium-air battery (LAB), because of its higher theoretical specific capacity (3860 mA h g-1) and its most negative redox potential (-3.04 V vs. SHE). During charging, however, it is well known that the dendrite, which further leads to poor performance and short circuit, forms on the lithium anode surface. In addition, solid electrolyte interphase (SEI), which is generated by decomposition of electrolytes and/or solvents, also accumulates on the anode surface during the anode reaction. An ideal SEI layer is expected to be higher and lower conductive for lithium ion and electron, respectively, and it is flexible and has a relatively uniform flat surface with an appropriate thickness, in order to avoid dendrite formation [1]. Thus, we have been trying to construct the “ideal SEI” on the electrode surface [2]. During the electrochemical reaction, on the other hand, electrochemical quartz crystal microbalance (EQCM) technique gives us information not only of mass change on the electrode surface but also resonance resistance change, which shows surface area change of the electrode [3,4] and/or density and viscosity change at the electrode/electrolyte solution interface [5,6]. Moreover, this technique provides us the viscoelasticity of the formed layers on the electrode by the admittance analysis. Using this technique, we found that the native-SEI, which is prepared by the pre-electrochemical treatment of Cu EQCM electrode, strongly effects on the lithium electrodeposition/dissolution processes. Acknowledgements: This work was totally supported by the Advanced Low Carbon Technology Research and Development Program (ALCA), specially promoted research for innovative next generation batteries (SPRING) from the Japan Science and Technology (JST).

Electrodeposition of Platinum Catalyst from Ionic Liquids

Both battery and fuel cell electric vehicles are important building blocks for the transition to sustainable transportation [1]. Fuel cell vehicles have been introduced into the market, but have not yet reached a wide market penetration due to high cost and limited refueling infrastructure. One important cost factor is due to the large amounts of platinum required because of the sluggish kinetics of the oxygen reduction reaction (ORR) [1]. Currently, the main pathway for minimizing the Pt content consists in nanostructuring of Pt and especially by using Pt alloys. Electrodeposition is an effective pathway for the preparation of Pt nanoparticles. By choosing suitable electrolysis conditions one can control the morphology and the size of the obtained particles [2]. Electrodeposition of pure Pt can be accomplished in aqueous solutions [3]. However, aiming at Pt alloys with very reactive alloying elements requires a non-aqueous approach. Especially suitable are ionic liquids (ILs). The main advantages of ILs are a wide electrochemical window, low flammability, a nearly non-existing vapor pressure, and often low toxicity [4, 5]. The electrodeposition of Pt using standard Pt precursors from some ILs has been reported [6-8]. In this study, the deposition of platinum from PtCl4 dissolved in the IL 1-methyl-1-octylpyrrolidinium bis(trifluoromethylsulfonyl)imide (OMP TFSI) was explored on boron doped diamond (BDD) and Au electrodes for the electrochemical quartz crystal microbalance technique (EQCM) at 60 °C. A typical cyclic voltammogram on BDD is shown in Figure 1a. After pulsed electrodeposition (-1.6V vs Pt, 1s, 0V, 4s, 30 minutes total) and transfer of the washed electrode to 0.1 M H2SO4, a characteristic Pt voltammogram was obtained (Figure 1b). EQCM permitted to monitor directly changes in the resonance frequency and damping associated with the Pt(IV) reduction processes. Based on these results, the implications for alloy deposition and application to practical catalyst synthesis are discussed. The project leading to this abstract has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under grant agreement No 700127. This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation Programme and Hydrogen Europe and Hydrogen Europe Research. Figure 1. Cyclic voltammogram of a) BDD in 50 mM PtCl4 in OMP TFSI at 60°C, 20 mV s-1 b) BDD after Pt deposition in 0.1 M H2SO4, 100 mV s-1 References [1] O. Gröger, H. A. Gasteiger, J.-P. Suchsland, J. Electrochem. Soc., 162, A2605-A2622 (2015). [2] X. Zhang, F. Shi, X. Yu, H. Liu, Y. Fu, Z. Wang, L. Jiang, X. Li, J. Am. Chem. Soc., 126, 3064 (2004). [3] J.V. Zoval, J. Lee, S. Gorer, R.M. Penner, J. Phys. Chem. B, 102, 1166 (1998). [4] M.C. Buzzeo, R.G. Evans, R.G. Compton, ChemPhysChem, 5, 1106 (2004). [5] F. Endres, ChemPhysChem, 3, 144 (2002). [6] D. Zhang, W. C. Chang, T. Okajima, T. Ohsaka, Langmuir, 27, 14662-14668 (2011). [7] P. He, H. Liu, Z. Li and J. Li, J. Electrochem. Soc., 152, E146 (2005). [8] L. Asen, W. Ju, E. Mostafa, S. Martens, U. Heiz, U. Stimming, O. Schneider, ECS Trans., 75, 323 (2016). Figure 1