Tetrafluoroborate Ion Research Articles

Comparative studies of cobalt hydroxide and nickel hydroxide designed using novel metal tetrafluoroborate as active materials of battery supercapacitor hybrids

Structure directing agent (SDA) can tailor morphology of active materials with preferable surface properties. Ammonium fluoroborate has been proposed as an effective SDA to synthesize metal organic framework (MOF) derivatives in previous reports, where fluoroborate ions play as morphology regulators by providing steric hindrance. Nickel and cobalt hydroxides are intensively used as active materials in battery supercapacitor hybrids (BSHs), owing to high theoretical capacitances and durability. However, previous studies rarely investigate metal specie effects on energy storage and compare electrochemical performance of nickel and cobalt hydroxides particularly in unique synthesis environments. In this study, nickel tetrafluoroborate (Ni(BF4)2) and cobalt tetrafluoroborate (Co(BF4)2) are respectively used as nickel and cobalt sources to synthesize hydroxides as active materials of BSHs. Tetrafluoroborate ions act as SDAs to design favorable morphologies, while 2-methylimidazole is incorporated to control the pH value for facilitating precipitations. The Ni(OH)2 and Co(OH)2 electrodes respectively show specific capacitances (CF) of 1118.5 and 334.3 F/g at 20 mV/s, owing to the preferable alpha-type hydroxide and larger pore volume/width for Ni(OH)2. A BSH consisted of a Ni(OH)2 positive electrode shows a maximum energy density of 64.0 Wh/kg at 700.0 W/kg, and the CF retention of 116 % and Coulombic efficiency of 94 % after 5000 cycles.

Ternary Rotational Polyanion Coupling Enables Fast Li Ion Dynamics in Tetrafluoroborate Ion Doped Antiperovskite Li2OHCl Solid Electrolyte

AbstractLi‐rich antiperovskite (LiRAP) hydroxyhalides are emerging as attractive solid electrolyte (SEs) for all‐solid‐state Li metal batteries (ASSLMBs) due to their low melting point, low cost, and ease of scaling‐up. The incorporation of rotational polyanions can reduce the activation energy and thus improve the Li ion conductivity of SEs. Herein, we propose a ternary rotational polyanion coupling strategy to fasten the Li ion conduction in tetrafluoroborate (BF4−) ion doped LiRAP Li2OHCl. Assisted by first‐principles calculation, powder X‐ray diffraction, solid‐state magnetic resonance and electrochemical impedance spectra, it is confirmed that Li ion transport in BF4− ion doped Li2OHCl is strongly associated with the rotational coupling among OH−, BF4− and Li2−O−H octahedrons, which enhances the Li ion conductivity for more than 1.8 times with the activation energy lowering 0.03 eV. This work provides a new perspective to design high‐performance superionic conductors with multi‐polyanions.

Ternary Rotational Polyanion Coupling Enables Fast Li Ion Dynamics in Tetrafluoroborate Ion Doped Antiperovskite Li2OHCl Solid Electrolyte.

Li-rich antiperovskite (LiRAP) hydroxyhalides are emerging as attractive solid electrolyte (SEs) for all-solid-state Li metal batteries (ASSLMBs) due to their low melting point, low cost, and ease of scaling-up. The incorporation of rotational polyanions can reduce the activation energy and thus improve the Li ion conductivity of SEs. Herein, we propose a ternary rotational polyanion coupling strategy to fasten the Li ion conduction in tetrafluoroborate (BF4-) ion doped LiRAP Li2OHCl. Assisted by first-principles calculation, powder X-ray diffraction, solid-state magnetic resonance and electrochemical impedance spectra, it is confirmed that Li ion transport in BF4- ion doped Li2OHCl is strongly associated with the rotational coupling among OH-, BF4- and Li2-O-H octahedrons, which enhances the Li ion conductivity for more than 1.8 times with the activation energy lowering 0.03 eV. This work provides a new perspective to design high-performance superionic conductors with multi-polyanions.

POTENTIOMETRY IN DETERMINING THE CONDITIONS FOR THE FORMATION OF TETRAFLUORBORATE AS AN ANALYTICAL FORM OF BORON

The present paper deals with the research on the optimal conditions for the formation of fluoroborate as an analytical form of boron. Despite numerous scientific publications related to the determination of boron using various methods involving [BF4]ˉ ions as an analytical form, the conditions for obtaining the latter differ significantly. This difference is likely due to the complexity of the H3BO3-F--H3O+ system, where polymolecular forms of hydrofluoric acid can exist. Factors such as the inability to measure pH using a glass electrode, the velocity of the complexation process, and the requirement for specialized labware and equipment resistant to aggressive environments contribute to this complexity. In this study, potentiometry with PVC plasticized [BF4]ˉ - sensors, known for their metrological and operational characteristics, was used as a convenient tool to investigate such systems. The [BF4]ˉ - selective electrode based on the electroactive substance ion pair 2-(N-ethylcarbazole-3)-ethenyl-1,3,3-trimethyl-3H-indole tetrafluoroborate, which retains its metrological characteristics in acidic and strongly acidic environments and exhibits selectivity up to F-(= -4. 0), was employed as a sensor.
 The sensor allowed for the study of [BF4]ˉ - complex formation under different reaction conditions by recording kinetic curves in EMF-time coordinates. The yield of the analytical form was estimated at different concentrations of acid, fluoride ions, and temperature. The obtained data were used to construct the yield surface of tetrafluoroborate, revealing that the optimal conditions for the formation and stability of tetrafluoroborate at room temperature are a medium of 1 M sulfuric acid and 0. 25 M NH4F. Under these conditions, the yield of [BF4]ˉ reaches 99% within 10 minutes. Although the use of phosphoric acid does not allow for the attainment of an appropriate yield of the analytical form under equilibrium conditions, its low process velocity makes it suitable for kinetic - potentiometric determination of boron. This characteristic was utilized to develop a method for the determination of boron in phosphoric acid using the fixed-time method.
 Keywords: tetrafluoroborate ion; potentiometric sensor; kinetic determination of boron.

Surface Modification of ZnO Nanocrystals with Conjugated Polyelectrolytes Carrying Different Counterions for Inverted Perovskite Light-Emitting Diodes.

In this work, bromide ions (Br-) on the conjugated polyelectrolytes (CPEs) were converted to tetrafluoroborate (BF4-) or hexafluorophosphate (PF6-) ions through anion exchange. The three CPEs (PFN-Br, PFN-BF4, and PFN-PF6) were utilized solely for surface modification of zinc oxide nanocrystals (ZnO NCs). The ionic groups on CPEs can form permanent dipoles to facilitate charge injection from ZnO NCs to cesium lead bromide (CsPbBr3) NC emitters, therefore promoting luminescent properties of inverted perovskite light-emitting diodes (PeLEDs). The experimental results reveal that ZnO NC films were smoothened by CPEs that allowed flat deposition of the perovskite active layers; moreover, the improved contact between ZnO and perovskite layers was beneficial for reducing leakage current, as verified in the dark current measurement of devices. In addition, the incorporation of CPEs helped to passivate the defects of ZnO NC films and prolong the carrier lifetime of CsPbBr3 NCs. PeLEDs based on different CPEs were then constructed and evaluated. The device based on PFN-Br showed the highest brightness and current efficiency, and the one based on PFN-BF4 exhibited better current efficiency over PFN-Br under the low current density below 160 mA/cm2. This is the first report using fluorene-based CPEs with Br-, BF4-, or PF6- groups to modify the properties of ZnO and CsPbBr3 NCs for the construction of inverted PeLEDs so far. Our experiments explored new kinds of CPEs on the surface modification of ZnO NCs and device performance of PeLEDs.

Functional Ionic Liquid Polymer Stabilizer for High-Performance Perovskite Photovoltaics.

The stability-related issues arising from the perovskite precursor inks, films, device structures and interdependence remain severely under-explored to date. Herein, we designed an ionic-liquid polymer (poly[Se-MI][BF4 ]), containing functional moieties like carbonyl (C=O), selenium (Se+ ), and tetrafluoroborate (BF4 - ) ions, to stabilize the whole device fabrication process. The C=O and Se+ can coordinate with lead and iodine (I- ) ions to stabilize lead polyhalide colloids and the compositions of the perovskite precursor inks for over two months. The Se+ anchored on grain boundaries and the defects passivated by BF4 - efficiently suppress the dissociation and migration of I- in perovskite films. Benefiting from the synergistic effects of poly[Se-MI][BF4 ], high efficiencies of 25.10 % and 20.85 % were exhibited by a 0.062-cm2 device and 15.39-cm2 module, respectively. The devices retained over 90 % of their initial efficiency under operation for 2200 h.

Functional Ionic Liquid Polymer Stabilizer for High‐Performance Perovskite Photovoltaics

AbstractThe stability‐related issues arising from the perovskite precursor inks, films, device structures and interdependence remain severely under‐explored to date. Herein, we designed an ionic‐liquid polymer (poly[Se‐MI][BF4]), containing functional moieties like carbonyl (C=O), selenium (Se+), and tetrafluoroborate (BF4−) ions, to stabilize the whole device fabrication process. The C=O and Se+ can coordinate with lead and iodine (I−) ions to stabilize lead polyhalide colloids and the compositions of the perovskite precursor inks for over two months. The Se+ anchored on grain boundaries and the defects passivated by BF4− efficiently suppress the dissociation and migration of I− in perovskite films. Benefiting from the synergistic effects of poly[Se‐MI][BF4], high efficiencies of 25.10 % and 20.85 % were exhibited by a 0.062‐cm2 device and 15.39‐cm2 module, respectively. The devices retained over 90 % of their initial efficiency under operation for 2200 h.

Ability of ionic liquids to inhibit the formation of methane hydrate: Insights from molecular dynamics simulations

Ionic liquids can both thermodynamically and kinetically inhibit the formation of solid hydrates in oil and gas pipelines, and thus are a new class of dual-function inhibitors of the formation of hydrates. In this study, the ability of six ionic liquids with different functional groups to inhibit the formation of methane hydrate was investigated using molecular dynamics simulations. The alkyl chains in ionic liquids strengthen the tetrahedral arrangement of water molecules by forming pentagonal and hexagonal ring structures with water molecules. In contrast, anionic groups weaken the tetrahedral arrangement of water molecules. The longer alkyl chain of the 1-butyl-3-methylimidazolium ion) (BMIM+) substantially enhanced the tetrahedral arrangement of water molecules, and thus BMIM+ exhibited less inhibition of the formation of methane hydrate than did the 1-ethyl-3-methylimidazolium ion (EMIM+). In general, the relative abilities of the various components of the studied ionic liquids to inhibit the formation of methane hydrates were found to be as follows: BMIM+ < EMIM+ < tetrafluoroborate ion ≈ bromide ion ≈ chloride ion. The findings of this study provide insights into mechanisms by which ionic liquids inhibit the formation of methane hydrate and have potential applications in the petroleum pipeline industry.

Determination of tetrafluoroborate in wastewaters by ion chromatography after ion pair liquid-liquid dispersive microextraction

The ion chromatographic method was developed to determine tetrafluoroborate ion (BF4-) in different types of water using ion pair liquid-liquid dispersive microextraction. Tetrafluoroborate was extracted into an organic phase (1,2-dichloroethane) as an ion pair with a tetrabutylammonium cation (TBA+). The most complete formation of [(ТBА+)(BF4-)] was observed at ion-pair reagent concentration of at least 5 mmol L-1 (C(BF4-) ≤ 1mg L-1). Ultrasonic irradiation was used to disperse the extractant. The achieved concentration factor (K) was 29±3, and the degree of extraction (R) was 50±5%. The limit of detection of tetrafluoroborate using the microextraction technique was 7×10-3 mg L-1. The method applies to the analysis of different water origins. The presence of the main contained anions does not interfere with the microextraction and chromatographic determination of tetrafluoroborate. The maximum molar ratio of BF4- to diverse ions is 1:104 for fluoride, chloride, bromide, nitrate ions, and 1:102 for sulfate and perchlorate ions.&#x0D;

Density functional theory on ionic liquid as carbonate scale dissolver in petroleum pipelines

The carbonate scale is the common oilfield scale found in the petroleum pipeline, which will cause flow assurance problems. In the purpose to conquer this problem, the alternative approach is to use ionic liquids (ILs) particularly in dissolving carbonate scale. The main objective of this study is to determine the effective ILs to dissolve carbonate scale in petroleum pipelines, and to evaluate the effect of intermolecular interaction in ILs toward their properties such as dissolution capabilities. The density functional theory (DFT) calculation is used to investigate the intermolecular interaction of a series of different ion pair, namely cations and anions-based of ILs with carbonate ion. All the calculations are completed by Gaussian software at the hybrid Becke 3-Lee-Yang-Parr (B3LYP) level using the 6-311++G(d, p) basis set. The optimized structure of carbonate ion and ion pairs of ILs have been obtained from the calculation which was further complemented by harmonic vibrational frequency, binding energies, bond type, bond order, and natural bond orbital (NBO). The binding energy for the cation and anion-based ILs are obtained where the ammonium ion is −302.2627 kJ/mol and tetrafluoroborate ion is −562.9194 kJ/mol which depict to have the highest value compare to others. Both of them are made up of the single bond and are characterized as the polar covalent bond. The NBO analysis pointed out the higher second-order perturbation energy, E (2) for ammonium ion is at a lone pair, LP (1) N 9 to antibonding sigma, BD*(1) O 3H 6 while BF4 ion is at lone pair LP (3) F 2 to antibonding lone pair, LP*(1) Ca 6. The selective ILs, ammonium tetrafluoroborate shown the higher negative binding energy which is −371.93 kJ/mol having the same nature of bond type and bond order from the findings in cation and anion-based ILs.

Ion regulation in double-network hydrogel module with ultrahigh thermopower for low-grade heat harvesting

Harvesting low-grade heat as source of electrical power has emerged as a research frontier for self-powered wearable devices, as a promising route to overcome challenges associated with limited access to grid power. However, such promise is compromised by current attainable thermopowers and constraints of rigid or complicated thermoelectric systems. We report an ultrahigh thermopower of 19.32 mV K−1 on a stretchable thermoelectric module by the assembly of porous electrodes and hybrid hydrogel, containing 1-ethyl-3-methylimidazolium and tetrafluoroborate ions and polyethylene glycol. The anions act as charge carrier; for the first time, distinct ion mobilities are directly measured by 2D-diffusion-ordered nuclear magnetic resonance spectroscopy. By regulating ion transport via the synergy of selective ion-localization and thermo-osmotic mechanism, such design provides an effective strategy to increase thermopower, and our device is endowed with high output power density, tailorable architecture, and excellent stretchability, which is showcased in a thermoelectric wristband for body heat recovery.

Synthesis of new ruthenium complexes and their use as catalysts in the hydrogenation of diene compounds

Ruthenium half-sandwich complexes [Cp*Ru (diene compound)]+X− containing various commercially available diene compounds as ligands were tested as catalysts for the hydrogenation of diene compounds. Complexes containing acyclic, cyclic, bicyclic dienes, and α,β-unsaturated carboxylic acids and their derivatives as diene ligands were successfully prepared. The anionic part of the complexes (X−) was represented by triflate, perchlorate and tetrafluoroborate ions. Hydrogenations were carried out in homogeneous and heterogeneous arrangements. The desired products with Z-configuration of the double bond were formed with high selectivity (95–99%) in both cases. It was found out that selectivity was influenced neither by the type of diene ligand nor by the type of the anionic part of the complex. The hydrogenation rate was influenced by the type and the size of the diene ligand. The rate of hydrogenation of diene using complexes containing isolated cyclic or bicyclic ligands was the highest. The lowest reaction rates were observed using complexes with acyclic dienes. The influence of the type of the anionic part of the complex on the reaction rate was also studied. The lowest rate of hydrogenation was observed using complexes with tetrafluoroborate anion. The difference in reaction rates using complexes with triflate and perchlorate anions was not significant. This work added important information for the understanding the mechanism of diene hydrogenation using ruthenium half-sandwich complexes.

Corrosion mechanism of sulfate, chloride, and tetrafluoroborate ions interacted with Ni-19 wt% Cr coating: A combined experimental study and molecular dynamics simulation

This study aimed to investigate the corrosion behavior of a relatively resistant nickel‑chromium coating in the presence of SO42−, Cl−, and BF4− ions. The electrochemical measurements including linear polarization, small amplitude cyclic voltammetry (SACV), and electrochemical noise (EN) analysis, were used, along with molecular dynamics simulation (MD) to evaluate the interactions between the coating and the corrosive ions. Results of the EN analysis showed that the charges of events exchanged in the HBF4 and HCl solutions were in the range of 1 μC to 1 mC; i.e., the coating was locally damaged in these media. However, the rates of pit progress in the coating exposed to BF4− and Cl− were not similar because the polarization resistances (Rp) of the coating in these two solutions were 1745.6 Ω·cm2 and 2766.2 Ω·cm2, respectively. The most negative adsorption energy, alongside the highest diffusion force of tetrafluoroborate ions, compared to chloride and sulfate, led to severe pitting corrosion of the coating. In the H2SO4 medium, the passivation mechanism prevailed over the pit growth, so that the Rp increased to 5747.3 Ω·cm2. Among the passive layers constructed on the coating surface, Cr2O3 (001) formed the low-energy chemical bonds with all three destructive species of SO42−, Cl−, and BF4−. Also, NiO (111) provided a compressed structure of Ni and Cr oxides, which could impede the penetration of corrosive ions in the alloyed coating.

Combination of sequential injection analysis with an integrated [BF4]-potentiometric sensor for the kinetic determination of boron

This work deals with the development of a kinetic technique for boron determination based on the monitoring of a tetrafluoroborate-formation reaction carried out in a potentiometric cell integrated with a sequential injection system. A previously elaborated PVC-membrane electrode based on the active substance formed by the ion pair of 2-[3-(5,6-dimethyl-3-nonyl-1,3-benzothiazol-2(3H)-ylidene)propenyl]-5,6-dimethyl-3-nonyl-1,3-benzothiazolium (DMNBT) with tetrafluoroborate ion was used. The metrological characteristics of the proposed sensor were tested in the presence and absence of F- in a concentration range of phosphoric acid from 0.1 to 7.0 M. The sensor is sensitive to tetrafluoroborate, with a slope of −56.5 ± 1.0 mV/pC and a LOD near pCmin = 6.7, and can be applied for the monitoring of the tetrafluoroborate-formation reaction in acidified fluoride solutions containing up to 7.0 M H3PO4 . The optimal reaction media that ensured sufficient difference in the response time of the sensor and the rate of [BF4]- appearance in the reaction media was 4.0 M H3PO4 and 0.2 M NH4F. The H-point standard addition method (HPSAM) was applied for the evaluation of selectivity. Its application was based on the fact that the response time of the sensor to the appearance of tetrafluoroborate and interferents in the reaction media was totally different. The proposed method was successfully applied for the determination of boron in unmineralised honey samples. Reliability of the results was tested using the ICP-MS method.

Ionic liquid tethered PEG-based polyurethane-siloxane membranes for efficient CO2/CH4 separation

This study introduces a new polyethylene glycol (PEG) based polyurethane-siloxane membrane containing a quaternary ammonium ionic liquid for CO2/CH4 separation. The designed ionic liquid was prepared in two steps: (i) (3-chloropropyl)triethoxysilane (CPS) and N,N-dimethylpropyl amine (NDPA) were reacted with each other to form the methoxysilane-functionalized quaternary ammonium component, then (ii) chloride ion (Cl−) of the product was exchanged with tetrafluoroborate ion (BF4−). The resulting compound, a reactive methoxysilane-functionalized ionic liquid (Si-IL) was chemically anchored to the polymer backbone through the sol-gel hydrolysis and condensation reaction. Based on the permeation tests, the IL containing PEG-based polyurethane-siloxane membranes at different concentration of Si-IL (XSi-PPUIL) were found to be potential candidates for CO2 removal from CH4. For instance, the CO2/CH4 selectivity of XSi-PPUIL membranes with the Si-IL content of 10 wt% was 3.3-fold greater than the Si-IL free membranes; while, the CO2 permeability for IL tethered membranes was 9.7% higher than the corresponding IL-free membrane.

Sensitivity of electrospray molecular dynamics simulations to long-range Coulomb interaction models.

Molecular dynamics (MD) electrospray simulations of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF_{4}) ion liquid were performed with the goal of evaluating the influence of long-range Coulomb models on ion emission characteristics. The direct Coulomb (DC), shifted force Coulomb sum (SFCS), and particle-particle particle-mesh (PPPM) long-range Coulomb models were considered in this work. The DC method with a sufficiently large cutoff radius was found to be the most accurate approach for modeling electrosprays, but, it is computationally expensive. The Coulomb potential energy modeled by the DC method in combination with the radial electric fields were found to be necessary to generate the Taylor cone. The differences observed between the SFCS and the DC in terms of predicting the total ion emission suggest that the former should not be used in MD electrospray simulations. Furthermore, the common assumption of domain periodicity was observed to be detrimental to the accuracy of the capillary-based electrospray simulations.

A High Efficacy Self‐Charging MoSe2 Solid‐State Supercapacitor Using Electrospun Nanofibrous Piezoelectric Separator with Ionogel Electrolyte

AbstractSelf‐charging supercapacitor power cell (SCSPC) received much attention for harvesting and storing energy in an integrated device, which paves the way for developing maintenance free autonomous power systems for various electronic devices. In this work, a new type of SCSPC device is fabricated comprising 2D molybdenum di‐selenide (MoSe2) as an energy storing electrode with polyvinylidene fluoride‐co‐hexafluoropropylene/tetraethylammonium tetrafluoroborate (PVDF‐co‐HFP/TEABF4) ion gelled polyvinylidene fluoride/sodium niobate (PVDF/NaNbO3) as the piezopolymer electrolyte. The fabricated SCSPC delivers a specific capacitance of 18.93 mF cm−2 with a specific energy of 37.90 mJ cm−2 at a specific power density of 268.91 µW cm−2 obtained at a constant discharge current of 0.5 mA. The MoSe2 SCSPC device can be self‐charged with the aid of mechanical deformation induced using the applied compressive force, thus making it harvest and store energy. The MoSe2 SCSPC device can be charged up to a maximum of 708 mV under a compressive force of 30 N in 100 s, and the mechanism of charge‐storage is discussed in detail. The experimental findings of this work demonstrate the high efficiency of the fabricated MoSe2 SCSPC device, which can provide new insights for developing sustainable power sources for the next generation wearable electronic applications.

Температурно-фазовая зависимость колебательного спектра и ориентационная подвижность тетрафторборат иона в органической соли н-Bu-=SUB=-4-=/SUB=-NBF-=SUB=-4-=/SUB=-

AbstractThe structural and dynamic properties of a tetrafluoroborate ion in n -Bu_4NBF_4 organic salt at different temperatures and phase states were studied by oscillation spectroscopy methods. The results of calculations of the energy and relaxation parameters have shown that in the plastic phase, a $${\text{BF}}_{4}^{ - }$$ ion is characterized by a low reorientation energy as compared with that of the crystalline phase.

Tetrafluoroborate and Hexafluorophosphate Ions are not Interchangeable: A Density Functional Theory Comparison of Hydrogen Bonding

AbstractDue to their similarities in charge and composition, the tetrafluoroborate (BF4−) and hexafluorophosphate (PF6−) ions are often used interchangeably in chemical studies. As a result, the ability of BF4−, but not PF6−, to inhibit the hydrolysis of alkyl thiosulfates in non‐aqueous solution was surprising. This divergence in reactivity may reflect differences in the ability of these ions to form strong hydrogen bonds to hydronium ion, which catalyzes the hydrolysis, and prompted the current computational studies. Calculations using density functional theory (DFT) gave atomic partial charges, occupation numbers, and energies relevant to hydrogen bonding of these anions. Topological analysis using the Atoms‐in‐Molecule (AIM) method elucidated the nature of the interactions, and natural‐bonding‐orbital (NBO) analysis provided insight on the strength of hydrogen bonding within the different tetrafluoroborate and hexafluorophosphate complexes. The calculated second‐order perturbation energies (E(2)) revealed that BF4− and H3O+ formed stronger hydrogen bonds than did PF6− and H3O+, suggesting that clusters formed by the former pair are more stable.

Functionalization of gold and graphene electrodes by p-maleimido-phenyl towards thiol-sensing systems investigated by EQCM and IR ellipsometric spectroscopy

Electrografting of gold and graphene surfaces by functional p‐(N‐maleimido)phenyl groups was performed by reduction of p‐(N‐maleimido)phenyldiazonium tetrafluoroborate. The reduction was carried out using cyclic voltammetry coupled with micro-gravimetric measurements by means of electrochemical quartz crystal microbalance (EQCM). The overall deposited mass on gold was higher than on graphene. However, the Faradaic efficiency was lower on Au (14%) compared to graphene (22%) after the first potential scan. Subsequently, the maleimide functional groups have been tested for immobilization of terminal thiols using (4-nitrobenzyl)mercaptan for the functionalized graphene surface and a cysteine-modified peptide for the functionalized gold surface. The functionalization by p‐(N‐maleimido)phenyl groups and the following thiol coupling of the particular surface was proven by infrared spectroscopic ellipsometry (IRSE). In addition, the interaction of the tetrabutylammonium and tetrafluoroborate ions present in the electrolyte with the Au and graphene electrodes was investigated by EQCM and revealed less electrostatic interaction of graphene with these ions in solution compared to the metal (Au) surface.