Electrochemical Quartz Crystal Microbalance Research Articles

Dual template (epitope) imprinted electrode for sensing bacterial protein with high selectivity.

Epitope imprinting has shown better prospects to synthesize synthetic receptors for proteins. Here, dual epitope imprinted polymer electrode (DEIP) matrix was fabricated on gold surface of electrochemical quartz crystal microbalance (EQCM) for recognition of target epitope sequence in blood samples of patients suffering from brain fever. Epitope sequences from outer membrane protein Por B of Neisseria meningitidis (MC58) bacteria predicted through immunoinformatic tools were chosen for imprinting. Self-assembled monolayers (SAM) of cysteine appended epitope sequences on gold nanoparticles were subjected to polymerization prior to electrodeposition on gold coated EQCM electrode. The polymeric matrix was woven around the cysteine appended epitope SAMs through multiple monomers (3-sulfo propyl methacrylate potassium salt (3-SPMAP), benzyl methacrylate (BMA)) and crosslinker (N, N'-methylene-bis-acrylamide). On extraction of the peptide sequences, imprinted cavities were able to selectively and specifically bind targeted epitope sequences in laboratory samples as well as 'real' samples of patients. Selectivity of sensor was examined through mismatched peptide sequences and certain plasma proteins also. The sensor was able to show specific binding towards the blood samples of infected patients, even in the presence of 'matrix' and other plasma proteins such as albumin and globulin. Even other peptide sequences, similar to epitope sequences only with one or two amino acid mismatches were also unable to show any binding. The analytical performance of DEIP-EQCM sensor was tested through selectivity, specificity, matrix effect, detection limit (0.68-1.01 nM), quantification limit (2.05-3.05 nM) and reproducibility (RSD ~ 5%). Hence, a diagnostic tool for bacterium causing meningitis is successfully fabricated in a facile manner which will broaden the clinical access and make efficient population screening feasible.

Understanding Electrolyte Ion Size Effects on the Performance of Conducting Metal-Organic Framework Supercapacitors.

Layered metal-organic frameworks (MOFs) have emerged as promising materials for next-generation supercapacitors. Understanding how and why electrolyte ion size impacts electrochemical performance is crucial for developing improved MOF-based devices. To address this, we investigate the energy storage performance of Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) with a series of 1 M tetraalkylammonium tetrafluoroborate (TAABF4) electrolytes with different cation sizes. Three-electrode experiments show that Cu3(HHTP)2 exhibits an asymmetric charging response with all ion sizes, with higher energy storage upon positive charging and a greater charging asymmetry with larger TAA+ cations. The results further show that smaller TAA+ cations demonstrate superior capacitive performances upon both positive and negative charging compared to larger TAA+ cations. To gain further insights, electrochemical quartz crystal microbalance measurements were performed to probe ion electrosorption during charging and discharging. These reveal that Cu3(HHTP)2 has a cation-dominated charging mechanism, but interestingly indicate that the solvent also participates in the charging process with larger cations. Overall, the results of this study suggest that larger TAA+ cations saturate the pores of the Cu3(HHTP)2-based electrodes. This leads to more asymmetric charging behavior and forces solvent molecules to play a role in the charge storage mechanism. These findings significantly enhance our understanding of ion electrosorption in layered MOFs, and they will guide the design of improved MOF-based supercapacitors.

The Role of Side Chains and Hydration on Mixed Charge Transport in n-Type Polymer Films.

Introducing ethylene glycol (EG) side chains to a conjugated polymer backbone is a well-established synthetic strategy for designing organic mixed ion-electron conductors (OMIECs). However, the impact that film swelling has on mixed conduction properties has yet to be scoped, particularly for electron-transporting (n-type) OMIECs. Here, the authors investigate the effect of the length of branched EG chains on mixed charge transport of n-type OMIECs based on a naphthalene-1,4,5,8-tetracarboxylic-diimide-bithiophene backbone. Atomic force microscopy (AFM), grazing-incidence wide-angle X-ray scattering (GIWAXS), and scanning tunneling microscopy (STM) are used to establish the similarities between the common-backbone films in dry conditions. Electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) and in situ GIWAXS measurements reveal stark changes in film swelling properties and microstructure during electrochemical doping, depending on the side chain length. It is found that even in the loss of the crystallite content upon contact with the aqueous electrolyte, the films can effectively transport charges and that it is rather the high water content that harms the electronic interconnectivity within the OMIEC films. These results highlight the importance of controlling water uptake in the films to impede charge transport in n-type electrochemical devices.

Investigation of Copper Codeposits with SiC Nano from Ionic Liquid (Ethaline) as Function of Concentration and Micro Particles Sizes where the Working Electrode in ‘Vertical’ Position Using Acoustic Impedance Electrochemical Quartz Crystal Microbalance (EQCM)

The gravimetric inspection of co-electrodeposited copper, with hard inert second phase ceramics SiC and 0.02 M [CuCl2.2H2O] in 1 ChCl: 2 EG, based liquid for different solution-phase loadings of 1-3 \(\mu\)m silicon carbide unpolished gold AT cut working electrode placed in’Vertical’ position, revealed that the EQCM method admits the first in-situ quantification or particulate inclusion. It was found that the composition of incorporated substance was fairly dependant on the concentration of second phase particles in solution, where in this study the 5% SiC has the amount in the copper which is in a good agreement with alumina particles with the same size. Another observation was that most of the material was drawn onto the surface rather than settling on to it, however the distribution of the hard phase was found to be reasonably even throughout the coating. This technology is important because it assists deposition of bright copper coatings without adding hazard materials, such as cyanide. On the other hand the comparison between concentrations of 0.02 M and 0.2 M [CuCl2.2H2O] in 1 ChCl: 2 EG based liquid for 10% solution-phase loadings of 45-55 nm size silicon carbide was also investigated, where the working electrode is placed in’Horizontal’ postion. It is very interisting that the experimental result showed that the mass loaded by 0.2 M solution is about 10 times greater than for the mass loaded by 0.02 M solution.

Electrified Interactions of Polyzwitterions with Charged Surfaces: Role of Dipole Orientation and Surface Potentials.

The zwitterionic groups possess strong dipole moments, leading to inter- or intrachain interactions among zwitterionic polymers. This study aims to demonstrate the interaction of polyzwitterions poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), and poly(carboxybetaine methacrylate) (PCBMA) with electrified surfaces, despite their electrically neutral nature. We studied the adsorption of polyzwitterions and their monomers on electrified surfaces by using an electrochemical quartz crystal microbalance with dissipation (EQCM-D). The interaction between zwitterionic molecules and charged surfaces is explored by adjusting the surface potentials. Interestingly, the adsorption of polyzwitterions can be influenced by external potential, primarily due to the formation of polyzwitterions restricting the mobility of zwitterionic groups, affecting the adsorption behavior of polyzwitterions based on the surface potential. The impact is determined by the arrangement of positive and negative ions within the zwitterionic groups, which are the dipole orientation. Additionally, surface potentials determine the adsorption rate, amount, and chain conformation of the adsorbed thin polyzwitterion layers. The effect of ionic strength was investigated by introducing electrolytes into the aqueous solutions to assess the range of influenced surface potentials.

Li+ Cations Activate NiFeOOH for Oxygen Evolution in Sodium and Potassium Hydroxide.

The efficiency of electrolysis is reduced due to the sluggish oxygen evolution reaction (OER). Besides catalyst properties, electrocatalytic activity also depends on the interaction of the electrocatalyst with the electrolyte. Here, we show that the addition of small amounts of Li+ to Fe-free NaOH or KOH electrolytes activates NiFeOOH for the OER compared to single-cation electrolytes. Moreover, the activation was maintained when the solution was returned to pure NaOH. Importantly, we show that the origin of activation by Li+ cations is primarily non-kinetic in nature, as the OER onset for the mixed electrolyte does not change and the Tafel slope at low current density is ~30 mV/dec in both electrolytes. However, the increase of the apparent Tafel slope remains lower at increasing current densities in the presence of Li+. Based on electrochemical quartz crystal microbalance and in situ X-ray absorption spectroscopy measurements, we show that this reduction of non-kinetic effects is due to enhanced intercalation of sodium, water and hydroxide. This enhanced electrolyte penetration facilitates the OER, especially at higher current densities and for increased catalyst loading. Our work shows that mixed electrolytes where distinct cations can have different roles provide a simple and promising strategy towards improved OER rates.

Li+ Kationen aktivieren NiFeOOH für die Sauerstoffentwicklung in Natrium‐ und Kaliumhydroxid

AbstractDie Effizienz der Elektrolyse wird durch die träge Sauerstoffentwicklung (OER) verringert. Neben den Katalysatoreigenschaften hängt die elektrokatalytische Aktivität auch von der Interaktion des Elektrokatalysators mit dem Elektrolyten ab. Hier zeigen wir, dass die Zugabe kleiner Mengen Li+ zu eisenfreien NaOH‐ oder KOH‐Elektrolyten NiFeOOH für die OER aktiviert, verglichen mit monokationischen Elektrolyten. Außerdem blieb der aktivierte Zustand erhalten, wenn zu reiner NaOH zurück gewechselt wurde. Wichtig ist, dass wir zeigen, dass der Ursprung der Aktivierung durch Li+‐Kationen in erster Linie nicht‐kinetischer Natur ist, da sich der Beginn der OER für den gemischten Elektrolyten nicht ändert und die Tafelsteigung bei niedriger Stromdichte in beiden Elektrolyten ~30 mV/dec beträgt. Der Anstieg der Tafelsteigung bleibt jedoch bei steigenden Stromdichten in Gegenwart von Li+ geringer. Basierend auf elektrochemischen Quarzkristall‐Mikrowaagen‐ und In situ‐Röntgenabsorptionsspektroskopie‐Messungen zeigen wir, dass diese Verringerung der nichtkinetischen Effekte auf eine verstärkte Interkalation von Natrium, Wasser und Hydroxid zurückzuführen ist. Diese verstärkte Elektrolytpenetration erleichtert die OER, insbesondere bei höheren Stromdichten und bei erhöhter Katalysatorbeladung. Unsere Arbeit zeigt, dass gemischte Elektrolyte, in denen verschiedene Kationen unterschiedliche Rollen einnehmen können, eine einfache und vielversprechende Strategie zur Verbesserung der OER‐Raten darstellen.

The Influence of Cathode Degradation Products on the Anode Interface in Lithium-Ion Batteries.

Degradation of cathode materials in lithium-ion batteries results in the presence of transition metal ions in the electrolyte, and these ions are known to play a major role in capacity fade and cell failure. Yet, while it is known that transition metal ions migrate from the metal oxide cathode and deposit on the graphite anode, their specific influence on anode reactions and structures, such as the solid electrolyte interphase (SEI), is still quite poorly understood due to the complexity in studying this interface in operational cells. In this work we combine operando electrochemical atomic force microscopy (EC-AFM), electrochemical quartz crystal microbalance (EQCM), and electrochemical impedance spectroscopy (EIS) measurements to probe the influence of a range of transition metal ions on the morphological, mechanical, chemical, and electrical properties of the SEI. By adding representative concentrations of Ni2+, Mn2+, and Co2+ ions into a commercially relevant battery electrolyte, the impacts of each on the formation and stability of the anode interface layer is revealed; all are shown to pose a threat to battery performance and stability. Mn2+, in particular, is shown to induce a thick, soft, and unstable SEI layer, which is known to cause severe degradation of batteries, while Co2+ and Ni2+ significantly impact interfacial conductivity. When transition metal ions are mixed, SEI degradation is amplified, suggesting a synergistic effect on the cell stability. Hence, by uncovering the roles these cathode degradation products play in operational batteries, we have provided a foundation upon which strategies to mitigate or eliminate these degradation products can be developed.

Chemical stability and reactivity of electrochemically grown manganese oxide films

The fundamental scientific challenge in fully harnessing the potential of manganese oxide compounds lies in understanding the interplay between microstructure, surface properties, and electrochemical reactivity. In this study, manganese oxides were synthesized via two distinct methods: electrodeposition trough anodic oxidation of Mn2+ in solution and direct anodic oxidation of metallic Mn. Employing electrochemical quartz crystal microbalance measurements under flow conditions, the deposited compounds were successfully identified as function of the applied anodic potentials, revealing a transition from Mn3O4 to Mn2O3. Furthermore, the MnO → Mn(OH)2 conversion was determined to be a critical step in the degradation process of manganese oxides. For the anodic oxidation process, the mere alkaline "pH effect" (solid product formation predicted from Pourbaix Diagram) was demonstrated to be insufficient to form a protective oxide/hydroxide layer on top of metallic Mn. Indeed, the addition of phosphate proved necessary for achieving this protective passive layer formation, particularly in pH 12.0 Na3PO4 electrolyte solution. Potentiostatic growth in the presence of phosphates demonstrated the progressive stabilization of the protective layer consisting of a mix of manganese oxide, hydroxide, and phosphate, as confirmed by Raman and X-ray photoemission spectroscopy. To provide a comprehensive framework for our findings, a revised Pourbaix Diagram for the Mn-H2O-PO43− system is proposed and discussed.

In situ real-time investigation of ruthenium electrodeposition behavior in HCl solution using EQCM

Industrial waste solutions are rich in precious metals, which are valuable secondary resources. In order to realize the separation and recovery of ruthenium by electrodeposition, this work used a combination of cyclic voltammetry (CV), chronoamperometry (I-t), and electrochemical quartz crystal microbalance (EQCM) to study the electrochemical behavior and electrodeposition mechanism of ruthenium in HCl solution. The results show that the reduction of ruthenium in HCl solution is influenced by hydrogen evolution reaction (HER) and chlorine evolution reaction, and the reduction process of ruthenium varies at different potentials. The reduction currents of Ru(VIII)/Ru(0) and Ru(IV)/Ru(III) are observed at 0.88 V and 0.6 V. The reduction of Ru(III) to Ru(0) at negative potentials starts at −0.2 V, with peak cathodic currents between −0.2 V and −0.5 V accompanied by a significant mass increase, which is confirmed to be the electrodeposition of metallic ruthenium by SEM and EDS. The microscopic morphology of the ruthenium coating is spherical particles, and the nucleation mode of electrodeposition is progressive nucleation. The HER leads to a macroscopic morphology of a cleaved lamellar structure, which is not tightly adhered to the substrate. The metallic ruthenium starts to oxidize and dissolve rapidly after 1.12 V, leading to a rapid degradation of the electrode surface quality.

Kinetic-Thermodynamic Promotion Engineering toward High-Density Hierarchical and Zn-Doping Activity-Enhancing ZnNiO@CF for High-Capacity Desalination

HighlightsThrough facial basicity adjustment, kinetically favorable ZnxNi1-xO@CF electrode was formed with a high density hierarchical structure and three dimensional open pores.The optimal Zn-doping ratio in ZnxNi1-xO@CF has excellent sodium storage and desalination performance (128.9 mg g-1).The mechanism of Na+ intercalation process was studied by electrochemical quartz crystal microbalance with dissipation monitoring in situ test and the activation mechanism of redox-inert Zn-doping on electrode materials was reported.

Cation desolvation-induced capacitance enhancement in reduced graphene oxide (rGO)

Understanding the local electrochemical processes is of key importance for efficient energy storage applications, including electrochemical double layer capacitors. In this work, we studied the charge storage mechanism of a model material - reduced graphene oxide (rGO) - in aqueous electrolyte using the combination of cavity micro-electrode, operando electrochemical quartz crystal microbalance (EQCM) and operando electrochemical dilatometry (ECD) tools. We evidence two regions with different charge storage mechanisms, depending on the cation-carbon interaction. Notably, under high cathodic polarization (region II), we report an important capacitance increase in Zn2+ containing electrolyte with minimum volume expansion, which is associated with Zn2+ desolvation resulting from strong electrostatic Zn2+-rGO interactions. These results highlight the significant role of ion-electrode interaction strength and cation desolvation in modulating the charging mechanisms, offering potential pathways for optimized capacitive energy storage. As a broader perspective, understanding confined electrochemical systems and the coupling between chemical, electrochemical and transport processes in confinement may open tremendous opportunities for energy, catalysis or water treatment applications in the future.

An acetate electrolyte for enhanced pseudocapacitve capacity in aqueous ammonium ion batteries

Ammonium ion batteries are promising for energy storage with the merits of low cost, inherent security, environmental friendliness, and excellent electrochemical properties. Unfortunately, the lack of anode materials restricts their development. Herein, we utilized density functional theory calculations to explore the V2CTx MXene as a promising anode with a low working potential. V2CTx MXene demonstrates pseudocapacitive behavior for ammonium ion storage, delivering a high specific capacity of 115.9 mAh g−1 at 1 A g−1 and excellent capacity retention of 100% after 5000 cycles at 5 A g−1. In-situ electrochemical quartz crystal microbalance measurement verifies a two-step electrochemical process of this unique pseudocapacitive storage behavior in the ammonium acetate electrolyte. Theoretical simulation reveals reversible electron transfer reactions with [NH4+(HAc)3]···O coordination bonds, resulting in a superior ammonium ion storage capacity. The generality of this acetate ion enhancement effect is also confirmed in the MoS2-based ammonium-ion battery system. These findings open a new door to realizing high capacity on ammonium ion storage through acetate ion enhancement, breaking the capacity limitations of both Faradaic and non-Faradaic energy storage.

Role of Surface Terminations for Charge Storage of Ti3C2Tx MXene Electrodes in Aqueous Acidic Electrolyte.

In this study, we used 2-Dimmensionnal Ti3C2 MXene as model materials to understand how the surface groups affect their electrochemical performance. By adjusting the nature of the surface terminations (Cl-, N/O-, and O-) of Ti3C2 MXene through a molten salt approach, we could change the spacing between MXene layers and the level of water confinement, resulting in significant modifications of the electrochemical performance in acidic electrolyte. Using a combination of techniques including in-operando X-ray diffraction and electrochemical quartz crystal microbalance (EQCM) techniques, we found that the presence of confined water results in a drastic transition from an almost electrochemically inactive behavior for Cl-terminated Ti3C2 to an ideally fast pseudocapacitive signature for N,O-terminated Ti3C2 MXene. This experimental work not only demonstrates the strong connection between surface terminations and confined water but also reveals the importance of confined water on the charge storage mechanism and the reaction kinetics in MXene.

Role of Surface Terminations for Charge Storage of Ti3C2Tx MXene Electrodes in Aqueous Acidic Electrolyte

AbstractIn this study, we used 2‐Dimmensionnal Ti3C2 MXene as model materials to understand how the surface groups affect their electrochemical performance. By adjusting the nature of the surface terminations (Cl‐, N/O‐, and O‐) of Ti3C2 MXene through a molten salt approach, we could change the spacing between MXene layers and the level of water confinement, resulting in significant modifications of the electrochemical performance in acidic electrolyte. Using a combination of techniques including in‐operando X‐ray diffraction and electrochemical quartz crystal microbalance (EQCM) techniques, we found that the presence of confined water results in a drastic transition from an almost electrochemically inactive behavior for Cl‐terminated Ti3C2 to an ideally fast pseudocapacitive signature for N,O‐terminated Ti3C2 MXene. This experimental work not only demonstrates the strong connection between surface terminations and confined water but also reveals the importance of confined water on the charge storage mechanism and the reaction kinetics in MXene.

Elucidating the Reduction Mechanism of Lithium Bis(oxalato)borate.

Electrolyte additives are indispensable to enhance the performance of Li-ion batteries. Lithium bis(oxalato)borate (LiBOB) has been explored for many years, as it improves both cathode and anode performance. No consensus regarding its reaction mechanisms has, however, been established. A model operando study combining attenuated total reflection infrared spectroscopy (ATR-FTIR), electrochemical quartz crystal microbalance (EQCM), and online electrochemical mass spectrometry (OEMS) is herein presented to elucidate LiBOB reduction and electrode/electrolyte interphases thus formed. Reduction of the BOB- ion sets in at ∼1.8 V with solid lithium oxalate and soluble oxalatoborates as the main products. The reduced BOB- ion also reacts with itself and its environment to evolve CO2, which in turn impacts the interphase formed on the negative electrode. This study provides further insights into the reduction pathways of LiBOB and how they contribute to the interphase formation.

Probe the Dynamic Adsorption and Phase Transition of Underpotential Deposition Processes at Electrode-Electrolyte Interfaces.

Electrochemical scanning tunneling microscopy (EC-STM) and electrochemical quartz crystal microbalance (E-QCM) techniques in combination with DFT calculations have been applied to reveal the static phase and the phase transition of copper underpotential deposition (UPD) on a gold electrode surface. EC-STM demonstrated, for the first time, the direct visualization of the disintegration of (√3 × √3)R30° copper UPD adlayer with coadsorbed SO42- while changing sample potential (ES) toward the redox Pa2/Pc2 peaks, which are associated with the phase transition between the Cu UPD (√3 × √3)R30° phase II and disordered randomly adsorbed phase III. DFT calculations show that SO42- binds via three oxygens to the bridge sites of the copper with sulfate being located directly above the copper vacancy in the (√3 × √3)R30° adlayer, whereas the remaining oxygen of the sulfate points away from the surface. E-QCM measurement of the change of the electric charge due to Cu UPD Faradaic processes, the change of the interfacial mass due to the adsorption and desorption of Cu(II) and SO42-, and the formation and stripping of UPD copper on the gold surface provide complementary information that validates the EC-STM and DFT results. This work demonstrated the advantage of using complementary in situ experimental techniques (E-QCM and EC-STM) combined with simulations to obtain an accurate and complete picture of the dynamic interfacial adsorption and UPD processes at the electrode/electrolyte interface.

Solid–electrolyte interphase formation during Li metal deposition in LiN(SO2F)2-based solvate ionic liquids

Solvate ionic liquids (SILs) are promising electrolytes for Li metal batteries. In this study, Li plating-stripping reactions in SILs were investigated using electrochemical quartz crystal microbalance measurements and X-ray photoelectron spectroscopy (XPS). SILs were prepared by mixing Li salt and glyme (triglyme or tetraglyme) in a 1:1 molar ratio. During the Li plating-stripping reaction, a reversible mass change was observed in LiN(SO2F)2 (LiFSA) based SILs. In contrast, a considerably higher mass change than the theoretical value calculated from the Faraday current was observed in the LiN(SO2CF3)2 (LiTFSA) based SILs, owing to the accumulation of decomposition products of electrolytes on the electrode surface. XPS depth profiling for the deposited Li suggested the formation of thin solid-electrolyte interphase (SEI) in the LiFSA-based SILs while considerably thicker SEI was formed in the LiTFSA-based SILs. The SEI formed in LiFSA-based SILs effectively suppressed the decomposition of electrolytes. Thus, LiFSA-based SILs are favorable for achieving highly reversible charge–discharge of Li electrodes in Li metal batteries.

Effects of Polydopamine Incorporation on the Nanostructure and Electrochemical Performance of Electrodeposited Polypyrrole Films

Polypyrrole films are commonly prepared as conductive electrode surfaces for a variety of applications. Recently, there has been increasing interest in improving the adhesive properties and biocompatibility of polypyrrole electrodes via the incorporation of bioinspired polydopamine within the polymer scaffold. However, very little is currently known about the structural effects of polydopamine incorporation during the electropolymerisation of hybrid films. In this work, we combine electrochemical quartz crystal microbalance studies, fundamental electrochemical characterisation, atomic force microscopy, and a suite of spectroscopic techniques in order to correlate changes in the structure and performance of polypyrrole–polydopamine films to the structural modifications of the nanostructure induced by polydopamine incorporation. The results indicate that polydopamine incorporation greatly increases the rate of hybrid film deposition, as well as improving adhesion, surface homogeneity, and wettability, with no compromise in charge transfer properties. Polydopamine incorporation is strongly suggested to occur in non-connected domains within a predominantly polypyrrole-like scaffold. We propose a two-step model of co-polymerisation and the subsequent surface adhesion of hybrid films. Results are expected to be of broad general interest to researchers utilizing polypyrrole and polydopamine to prepare tailor-made electrodes for biosensing and catalysis.

Mechanism of mitigating organic fouling on an electro-conductive membrane under anaerobic conditions and cathodic operation

Anaerobic electroconductive membrane (ECM) bioreactors are promising wastewater treatment technology, yet their organic antifouling mechanism remains unclear. This research investigated the impact of reactive oxygen species (ROS) oxidation, pH alteration, and electrostatic repulsion on carbon nanotube-based ECM organic fouling. Using a decoupled anode–cathode filtration system ensured unbiased results from the anode while studying distinct conditions near the cathodic ECM surface. The results demonstrated a 50 % reduction in transmembrane pressure (TMP) onset applying potential due to electroosmosis, emphasizing its importance in fouling studies. Fouling experiments using alginate in synthetic wastewater solution showed substantial organic fouling at open circuit potential, −1 and −1.5 V, as the TMP increased by about 2.5 times than the initial value. Fouling decreased significantly at −2.5 V (vs. Ag/AgCl), as indicated by the stable TMP. Analysis of ROS effects and fouling experiments at pH 7–––12 found no influence on organic fouling. Simplified force balance analysis and filtration tests suggested electrostatic repulsion as the antifouling mechanism. At potentials below −2.5 V, electrostatic repulsion maximizes closer to the ECM surface, causing fouling from short-range attractive forces. Electrochemical quartz crystal microbalance analysis at 0.1 V (vs. Ag/AgCl) proposed that a smooth ECM surface can reduce organic fouling at lower potentials.