Electrochemical Reaction Mechanism Research Articles

Reasonable design of PBA-derived interfacial modified ternary compounds and hollow structure materials in high-performance asymmetric supercapacitors

Prussian blue analogues (PBA), common metal-organic frameworks (MOFs), are typically binary metal compounds. In this study, chromium was incorporated during the preparation of nickel‑cobalt PBA, resulting in the adjustment of the micro-morphology of PBA and the synthesis of small-sized PBA (sPBA) electrode materials with diameters ranging from 20 to 30 nm. These materials underwent various interfacial modifications to yield ternary metal phosphide (sPBA-P) and hollow nanostructures (sPBA-C). Additionally, by integrating graphene oxide (GO) as the growth substrate, successful preparation of GO@sPBA-P and GO@sPBA-C electrode materials was achieved. Significantly, these materials showcase outstanding electrochemical properties and interesting interfacial reactions when employed as cathode and anode components. Through a comprehensive series of characterization analyses, the electrochemical properties and reaction mechanisms of these materials were thoroughly investigated. Ultimately, an asymmetric supercapacitor (ASC) was assembled using the synthesized GO@sPBA-P and GO@sPBA-C to explore the material's potential in energy materials applications.

Charge injection mediated by inverse micelles in nonpolar solvents: A microscopic model

HypothesisNonpolar solvents with added charge control agents are widely used in various applications, such as E-paper displays. In spite of previous work, the mechanisms governing charge generation in nonpolar liquids, particularly those induced by electrochemical reactions at the liquid-solid interface, are not completely understood. We hypothesize that a physics-based model, according to the modified Butler–Volmer equation, can be used to quantitatively predict the injection of charges and the corresponding currents, in nonpolar solvents with surfactants. Simulation and ExperimentsWe propose a model to describe the migration and charge generation of inverse micelles. In addition to the mechanisms of electromigration, diffusion and charge generation via disproportionation that were introduced in earlier models, we include charge generation via electron injection at the electrodes using a microscopically justified expression as opposed to the previously used semi-empirical approaches. To validate our model, we compare its results to experimental current measurements in a simplified, effectively 1D, geometry. FindingsWe find that the incorporation of both bulk and electrochemical reaction mechanisms in the model can effectively explain the experimental steady-state currents in a wide range of concentrations, voltages (0.5 V-5 V), and cell thicknesses. These numerical results of currents at longer time scales show a steady-state current only when both bulk and electrochemical reactions are taken into account. Moreover, we have observed in our simulation that at low applied voltages, the electric field in the bulk is fully shielded, and the steady-state current in this low-voltage regime is governed by the charge injection at the electrodes. Conversely, when the voltage is high enough and the electric field remains partially unscreened, the bulk disproportionation mechanism dominates the current generation. This also explains why we observe a non-Ohmic behavior where the steady-state currents at high voltages are independent of applied voltage. Hence, by elucidating the physical processes underlying the experimental observations, our model offers a more profound comprehension of charge transport in these systems, which could facilitate advancements in the design of enhanced E-ink displays and smart windows.

Energy storage chemistry: Atomic and electronic fundamental understanding insights for high-performance supercapacitors

The scarcity of fuels, high pollution levels, climate change, and other major environmental issues are critical challenges that modern societies are facing, mostly originating from fossil fuels-based economies. These challenges can be addressed by developing green, eco-friendly, inexpensive energy sources and energy storage devices. Electrochemical energy storage materials possess high capacitance and superior power density. To engineer highly efficient next-generation electrochemical energy storage devices, the mechanisms of electrochemical reactions and redox behavior must be probed in operational environments. They can be studied by investigating atomic and electronic structures using in situ x-ray absorption spectroscopy (XAS) analysis. Such a technique has attracted substantial research and development interest in the field of energy science for over a decade. The mechanisms of charge/discharge, carrier transport, and ion intercalation/deintercalation can be elucidated. Supercapacitors generally store energy by two specific mechanisms—pseudocapacitance and electrochemical double-layer capacitance. In situ XAS is a powerful tool for probing and understanding these mechanisms. In this Review, both soft and hard x rays are used for the in situ XAS analysis of various representative electrochemical energy storage systems. This Review also showcases some of the highly efficient energy and power density candidates. Furthermore, the importance of synchrotron-based x-ray spectroscopy characterization techniques is enlightened. The impact of the electronic structure, local atomic structure, and electronically active elements/sites of the typical electrochemical energy storage candidates in operational conditions is elucidated. Regarding electrochemical energy storage mechanisms in their respective working environments, the unknown valence states and reversible/irreversible nature of elements, local hybridization, delocalized d-electrons spin states, participation of coordination shells, disorder, and faradaic/non-faradaic behavior are thoroughly discussed. Finally, the future direction of in situ XAS analysis combined with spatial chemical mapping from operando scanning transmission x-ray microscopy and other emerging characterization techniques is presented and discussed.

Electrocatalytic degradation of flutamide an anti-prostate cancer drug and its metabolite 4-nitro-3-(trifluoromethyl) aniline using a simple graphite/β-PbO2 electrode

Flutamide is an anti-androgen drug used to treat prostate cancer. It has been determined that this drug exists in aqueous environments at ng/L levels. On the other hand, the environmental impacts of flutamide (FLU) have not yet been determined. This paper reports a simple electrocatalytic convergent-paired strategy for the degradation of FLU and its metabolite 4-nitro-3-(trifluoromethyl) aniline (NTA) using a simple graphite/β-PbO2 anode. The prepared electrode has good electrochemical stability and lifetime (more than 60 h). The results showed that the degradation efficiency of FLU and NTA under optimal conditions (pH 5.0, pollutant concentration 138 ppm and applied current density 4.9 mA/cm2) is 86 and 99 %, respectively. Also, in the solution containing both FLU and NTA with a concentration of 138 ppm of each compound, the degradation efficiency of FLU and NTA is 82 % and 92 %, respectively. Furthermore, we have comprehensively investigated the electrochemical behavior of FLU and NTA and we compared the electrochemical similarities and differences of the drug with its metabolite, and also reported important data such as electrochemical reaction mechanism, pH-potential relationship, and drug absorption/diffusion activity.

Intercalation of Al3+ into Prussian Blue Analogues from Nonaqueous Electrolytes.

Nonaqueous aluminum-ion batteries (AIBs) provide advantages, such as high energy density, enhanced safety, and reduced corrosion, making them ideal for advanced energy storage solutions. A key challenge faced by AIBs is the lack of suitable cathode materials for rapid Al-ion insertion /extraction. Herein, K2Mn[Fe(CN)6] 2H2O (KMHCF) is innovatively chosen as a model to investigate the aluminum storage performance of Prussian blue analogues in nonaqueous AIBs. As anticipated, the KMHCF allows for reversible aluminum storage and exhibits characteristic charge/discharge plateaus. Furthermore, carbon combined highly crystalline KMHCF (HC-KMHCF@C) is synthesized through a chelator-assisted preparation method in combination with an in situ carbon compositing technique. With reduced [Fe(CN)6]4⁻ defects, lower interstitial water content, and enhanced conductivity, HC-KMHCF@C exhibits a high aluminum storage capacity (146.2 mAh g⁻¹ at 0.5 A g⁻¹) and satisfactory cycling performance (maintaining 86.4 mAh g⁻¹ after 800 cycles). The electrochemical reaction mechanism of HC-KMHCF@C is investigated in detail. During the initial charge, K⁺ ions are extracted, shifting the structure from monoclinic to cubic. In subsequent cycles, reversible Al3+ insertion and extraction cause the structure to alternate between monoclinic and cubic phases.

Incorporating Ag into Nd-Succinate MOF: Tunned electrochemical supercapacitor behaviour of Ag modified Nd-Succinate and electrochemical reaction mechanism

The electrode materials must be tailored to achieve higher energy and power densities and thus improve the supercapacitor's performance. This study explores the impact of incorporating Silver (Ag) into a Neodymium-Succinate Metal Organic Framework (Nd-Succinate) on supercapacitor behaviour. Initially, the Nd-Succinate MOF was characterized by structural, morphological, and spectroscopic characterizations. Subsequently, Ag/Nd-Succinate was synthesized and characterized. The electrochemical performance of Ag/Nd-Succinate was evaluated in a 6 M KOH electrolyte; the results indicated a significant enhancement in supercapacitor performance upon incorporating Ag into parent Nd-Succinate. From galvanostatic Charge-Discharge cycles (GCD), the capacitance for Ag/Nd-Succinate was determined to be 1389 F/g, i.e., 42 % higher than that of bare Nd-Succinate which was measured at 978 F/g. at a current density of 1.25 A/g. Ag/Nd-Succinate showcased an 89 % retention value for multiple retention cycles, slightly higher than the retention value obtained (84 %) for Nd-Succinate. The results of electrochemical experiments (Cyclic voltammetry (CV) and Electrochemical Impedance Spectra (EIS)) provided information about the nature of electron transfer and capacitance enhancement upon the introduction of Ag into Nd-Succinate. These findings provide valuable information on modifying MOFs and introducing metal that will help produce high-performance supercapacitor electrodes.

Transmembrane Graphene as an Electron Tunnel to Regulate the Intracellular Redox State.

Cellular redox homeostasis is essential for maintaining cellular activities, such as DNA synthesis and gene expression. Inspired by this, new therapeutic interventions have been rapidly developed to modulate the intracellular redox state using artificial transmembrane electron transport. However, current approaches that rely on external electric field polarization can disrupt cellular functions, limiting their in vivo application. Therefore, it is crucial to develop novel electric-field-free modulation methods. In this work, we for the first time found that graphene could spontaneously insert into living cell membranes and serve as an electron tunnel to regulate intracellular reactive oxygen species and NADH based on the spontaneous bipolar electrochemical reaction mechanism. This work provides a wireless and electric-field-free approach to regulating cellular redox states directly and offers possibilities for biological applications such as cell process intervention and treatment for neurodegenerative diseases.

In Situ Characterization Techniques for Electrochemical Nitrogen Reduction Reaction.

The electrochemical reduction of nitrogen to produce ammonia is pivotal in modern society due to its environmental friendliness and the substantial influence that ammonia has on food, chemicals, and energy. However, the current electrochemical nitrogen reduction reaction (NRR) mechanism is still imperfect, which seriously impedes the development of NRR. In situ characterization techniques offer insight into the alterations taking place at the electrode/electrolyte interface throughout the NRR process, thereby helping us to explore the NRR mechanism in-depth and ultimately promote the development of efficient catalytic systems for NRR. Herein, we introduce the popular theories and mechanisms of the electrochemical NRR and provide an extensive overview on the application of various in situ characterization approaches for on-site detection of reaction intermediates and catalyst transformations during electrocatalytic NRR processes, including different optical techniques, X-ray-based techniques, electron microscopy, and scanning probe microscopy. Finally, some major challenges and future directions of these in situ techniques are proposed.

Scaling of Planar Sodium‐Nickel Chloride Battery Cells to 90 cm2 Active Area

High‐temperature sodium‐nickel chloride (Na‐NiCl2) batteries offer a competitive solution for stationary energy storage due to their long‐term stability, high energy efficiency, and sustainable raw materials. However, scaling up this technology faces challenges related to the costly integration of tubular Na‐β''‐alumina ceramic electrolytes into hermetically sealed battery cells. Alternative cell designs with a planar Na‐β''‐alumina ceramic electrolyte have been a focus of research for many years, and a series of achievements were made on cell design, on reduction of the operating temperature, and on the analysis of electrochemical reaction mechanisms. However, the data presented in these reports was derived from laboratory‐scale cells with small area (1‐5 cm2). To date, there has been no research conducted on enlarging planar cells to an economically viable size. Here we report the fabrication of large planar Na‐β''‐alumina electrolytes and their integration into planar Na‐NiCl2 cells with 90 cm2 active area and >7 Ah capacity. Our cell design enabled cycling at 300 °C for three months, transferring a cumulative capacity of 323 Ah. We discuss design and engineering considerations for large planar high‐temperature cells emphasizing the need for cell stacking to compete with tubular Na‐NiCl2 batteries in terms of mass‐specific energy.

Facile and efficient fabrication of Cu1.04Mn0.96O2 nanosheet anodes with superior electrochemical lithium storage capability

In this work, Cu1.04Mn0.96O2 nanosheets were synthesized via a simple hydrothermal method, and their electrochemical lithium storage properties and reaction mechanisms were investigated. The nanosheet structure effectively promotes electron transfer and shortens the transport path. Additionally, the partial substitution of Cu for Mn decreases the Jahn-Teller distortion of the MnO6 octahedron. Employing as an anode for Li-ion batteries, the specific capacity reached 610.91 mAh g−1 after 100 cycles at a current density of 100 mA g−1.

(Invited) Understanding Electrochemical Reaction Mechanisms of Sulfur in All-Solid-State Batteries through Operando and Theoretical Studies

All-solid-state lithium-sulfur batteries (ASLSBs) have been considered a promising next-generation energy storage technology due to their remarkable safety and high energy density. In ASLSBs, the electrochemical pathways are intrinsically different from conventional Li-S batteries using liquid electrolytes. However, the mechanism still lacks clear identification and deep understanding. Herein, for the first time, we investigated the chemistries and explored the electrochemical reaction mechanism in ASLSBs through coupling operando Raman spectroscopy and ex-situ X-ray absorption spectroscopy. We proved that no long-chain lithium polysulfides (Li2Sn, 4≤n≤8) were formed during the redox reactions, but a short-chain polysulfide (Li2S2) intermediate phase formation was identified in the conversion between active material S8 and reduction product Li2S. This evidence explains the electrochemical behavior differences of Li-S batteries when using liquid and solid electrolytes. Moreover, there are partial S8 and Li2S2 remaining at the cathode even at fully lithiation stage, suggesting the sluggish reaction kinetics in the ASLSBs. This study revealed the generation of Li2S2 intermediates in ASLSBs, inspiring future research to further improve the performance of ASLSBs through completing the conversions and promoting reaction kinetics in ASLSBs.

Unveiling Reaction Mechanisms of Non-Aqueous Zn-Ion Batteries – Zn/LiFePO4 System

Zinc-ion batteries (ZIBs) are among the most promising energy storage technologies because of their low cost, safety, and environmental friendliness. In this work, we focus on investigating the electrochemical reaction mechanisms of ZIBs with Lithium iron phosphate (LiFePO4) as an active material in the positive electrode, Zn(OTf)2+LiCl dissolving Tetraethylene glycol dimethyl ether (TEGDME) as the electrolyte, as well as metallic Zinc as the negative electrode. After testing the ZIB cells by galvanostatic cycling, the cells with TEGDME exhibit the best electrochemical performance in terms of long-term stability. The initial specific discharge capacity is 118.3 mAh g-1 and the capacity retention is 91.4% after 100 cycles at a current density of 10 mA g-1. We propose the reaction mechanisms during the charge-discharge processes involve extraction/insertion processes of Li+ into/out of the olivine structure of LiFePO4 as evidenced by X-ray near-edge spectroscopy (XANES). According to X-ray diffraction (XRD) analysis of the discharged and charged LiFePO4 electrodes, the crystal structure changes from LiFePO4 to FePO4 when charging and back into LiFePO4 again when discharging. Besides, XRD and scanning electron microscopy (SEM) confirm that the cycled Zn electrode is hardly present with passivation and/or corrosion. Therefore, this new combination of Zn/LiFePO4 and TEGDME has a potential for ZIB applications.

Synthesis of Highly Oriented Nanocrystal Thin-Films and Their Applications to Electrochemical Devices

The precisely defined particle assembly at the nanoscale with simultaneously scalable patterning at the microscale is indispensable for enabling functionality and improving the performance of devices. While synthetic advances in the past decades now allow precise control of their size, shape, and composition, they must be processed from dispersion into functional films for many applications, which presents additional challenges. In this work, we introduce the self-assembly of inorganic nanoubes (Co3O4 NCs) and we also describe the fabrication of centimeter-scale NC superlattice thin-films on silicone substrate with anisotropic NC building blocks, thin-film patterning, and the supercrystal formation of superlattice structures. As a result, the Raman spectra of Co3O4 NC thin-films clearly exhibits the distinct feature of vibration modes of Co3O4 and synchrotron-based X-ray diffraction techniques showed the Co3O4 NCs order into [100] aligned arrays. Also, the uniformly prepared Co3O4 NC building blocks and thin-films were examined by field-emission scanning electron microscopy analysis and it shows well-defined nanostructures with ~13nm-side of NCs and ~3nm space between self-assembled NCs. To investigate the distinct feature of functional films, we prepared various type of device structures (memory, electrode, gas sensor) and examined the performances. In case of memristor, the device exhibits excellent bipolar resistance switching characteristics with better reliability and stability over various polycrystalline metal oxide nanostructures. Utilizing our approach enables the creation of miniaturized devices, followed by the transfer of NC thin-films onto TEM grids. Subsequent in-situ TEM analysis offers the potential to observe unique phenomena at the nano-scale, unveiling phase transitions in nanocrystalline materials or electrochemical reaction mechanisms previously unexplored by researchers.

Design and Construction of Carbon-Coated Bimetallic Selenide Heterostructures Loaded on Reduced Graphene Oxide Substrate for Superior Lithium-Ion Storage.

In this work, carbon-coated bimetallic tin-nickel selenide heterostructures loaded on reduced graphene oxide composites were prepared through a metal-organic framework-assisted strategy. The carbon coating mitigates the volume expansion and maintains the structural stability, while the introduction of reduced graphene oxide and heterojunction enhances electrical conductivity and reaction kinetics, thereby together contributing to the enhanced lithium-ion storage performance. As expected, the optimal material delivers excellent lithium-ion storage performance in terms of a high reversible capacity of 1033.4 mAh g-1 at 0.2 A g-1, outstanding rate capability, and long-term cyclability with the capacity of 726.2 mAh g-1 after 500 cycles at 1.0 A g-1 and 452.4 mAh g-1 after 1000 cycles at 2.0 A g-1. Furthermore, the electrochemical reaction mechanism of the composite is analyzed.

A room-temperature liquid eutectic GaSn anode with regulated wettability for lithium ion batteries

The alloy-type anodes in lithium ion batteries (LIBs) often suffer from the pulverization/failure of active materials caused by the drastic volume variations during cycling. Liquid Ga-based materials with low melting points and intrinsic self-healing feature are one of the best candidates for enhancing the Li storage property. Herein, a liquid eutectic GaSn (EGaSn) electrode was fabricated based upon a simple painting method and directly used as the anode for LIBs at room temperature. Furthermore, the wettability of liquid EGaSn alloy on the current collector in the Ar atmosphere was greatly improved through the construction of Ag3Ga modified layer on the stainless steel mesh (ssm) surface. And the Ag3Ga-EGaSn anode displays the much better Li storage performance (specific capacity, rate performance and cycling stability) than the untreated EGaSn anode. More importantly, operando XRD measurement clearly clarified the electrochemical reaction mechanism of Ag3Ga-EGaSn in LIBs. This work indicates a potential strategy to directly use liquid Ga-based electrode with regulated wettability for LIBs.

A highly stable insertion type V1-xTixP solid solution as an anode material for high-rate lithium-ion batteries

As electric vehicles (EVs) grow in popularity, the demand for lithium-ion batteries (LIBs) simultaneously grows, and the fast-charging capability is becoming increasingly important. However, it is generally believed that graphite anode still suffers from a poor rate capability for fast-charging applications, and other insertion-type oxide anodes with a high rate capability exhibit too high Li+-ion insertion/extraction potential, which cannot meet a requirement for high energy density anodes. In this work, the hexagonal structure of V1-xTixP (x = 0.0, 0.25, and 1.0) phases were introduced as insertion-type anode materials for LIBs with a low reaction potential of Li+-ion insertion/extraction. The crystal structure and the corresponding electrochemical reaction mechanism of insertion-type anodes of TiP, VP, and MoP were compared. A facile strategy forming a substitutional solid solution is suggested to improve the electrochemical properties of anode materials by combining the end members among insertion-type VP, TiP, and MoP as forming V1-xTixP and V1-xMoxP compounds. V1-xTixP (x = 0.25) electrode, substituting V atoms with Ti atoms in VP structure, shows excellent long-term cycle stability at 1 A/g with a cycle retention of 87.7 % during 2500 cycles, delivering a two times higher capacity of 211.1 mAh g−1 compared to that of the commercial graphite electrode.

In situ monitoring of cycling characteristics in lithium-ion battery based on a two-cavity cascade fiber-optic Fabry-Perot interferometer

The state characterization inside the lithium-ion battery during charge/discharge cycling is extremely crucial for understanding the electrochemical reaction mechanism. However, current methods exhibit a challenge to overcome the specific battery environment obstacles, including strong redox properties, strong electromagnetic interference, and fast reaction processes. Hence, more efforts are still needed to monitor the actual state inside the battery accurately and reliably. To address this issue, we designed and developed a compact two-cavity cascade fiber-optic Fabry-Perot interferometer (FPI) sensor that can be safely implanted in batteries to measure internal temperature and pressure simultaneously. With its high pressure and temperature sensitivity of 26.6 ​nm/kPa and 107 ​nm/°C, this sensor exhibits an ultra-low cross-sensitivity of −40 ​Pa/°C. During charge/discharge cycling tests, regular cyclic pressure and temperature signals are obtained at various rates cycling in real-time and in situ, revealing details about the actual state characterization inside the battery. From the experiment results, the pressure inside the battery is divided into reversible changes caused by respiration effects and irreversible changes caused by trace gas production. Furthermore, the FPI sensor provides a more precise temperature than thermocouples that measure the surface temperature of the battery, reflecting the internal/external temperature difference to a maximum of 3.5 ​°C at 1 ​C rate cycling. This operando FPI sensor provides a valuable technological tool for battery performance testing and safety monitoring.

Combinational Intercalation-Conversion-Intercalation reaction of CuInS2@PPy anode for Sodium-Ion batteries

Polypyrrole-coated CuInS2 (CuInS2@PPy) composite was prepared through the chemical vapor transport method and subsequent in situ polymerized coating strategy. In this unique nanoarchitecture, the PPy coating layer plays a crucial role in improving the conductivity of the composite, suppressing the volume change of CuInS2, and maintaining the structural integrity of electrode material upon cycling. In addition, the electrochemical reaction mechanism and kinetics of CuInS2@PPy were investigated in-depth. Benefitting from the synergism of its combinational intercalation-conversion-intercalation reaction mechanism and the high conductivity of the PPy coating layer, CuInS2@PPy electrode exhibits superior rate capability and cycling stability for sodium-ion batteries, with a capacity of 404.8 mA h g−1 at 4 A g−1 over 2500 cycles.

Discovering Facet-Dependent Formation Kinetics of Key Intermediates in Electrochemical Ammonia Oxidation by a Electrochemiluminescence Active Probe.

Facile evaluation of formation kinetics of key intermediate is crucial for a comprehensive understanding of electrochemical ammonia oxidation reaction (AOR) mechanisms and the design of efficient electrocatalysts. Currently, elucidating the formation kinetics of key intermediate associated with rate-determining step is still challenging. Herein, 4-phtalamide-N-(4'-methylcoumarin) naphthalimide (CF) is developed as a molecular probe to detect N2H4 intermediate during AOR via electrochemiluminescence (ECL) and further investigated the formation kinetics of N2H4 on Pt catalysts with different crystal planes. CF probe can selectively react with N2H4 to release ECL substance luminol. Thus, N2H4 intermediate as a key intermediate can be sensitively and selectively detected by ECL during AOR. For the first time, Pt(100) facet is discovered to exhibit faster N2H4 formation kinetics than Pt(111) facet, which is further confirmed by Density functional theory calculation and the finite element simulation. The AOR mechanism under the framework of Gerischer and Mauerer is further validated by examining N2H4 formation kinetics during the dimerization process (NH2 coupling). The developed ECL active probe and the discovered facet-dependent formation kinetics of key intermediates provide a promising new tool and strategy for the understanding of electrochemical AOR mechanisms and the design of efficient electrocatalysts.

Electrochemical Behaviour and Sensing of Chlorpromazine at Polymer‐Free Kaolin‐Based Nanosodalite and Nanosodalite‐Graphene Foam Film modified Glassy Carbon Electrodes

AbstractA nanosodalite (SOD) was synthesized utilizing Cameroonian kaolin and then used to prepare a nanocomposite (SOD‐GF) with graphene foam (GF). The as‐synthesized materials were characterized using X‐ray diffractometry (XRD), Fourier transform‐infrared (FT‐IR) spectroscopy, N2 adsorption‐desorption and scanning electron microscopy coupled with emission dispersive X‐ray (SEM/EDX). The results show a pure sodalite with high degree of crystallinity with crystallite size and BET surface area of 38.3 nm and 22 m2/g, respectively. The composite's characterization revealed a well‐integrated material in which the structural integrity of each material is maintained, its surface area being 4‐fold that of pristine SOD. Stable SOD and SOD‐GF modified glassy carbon electrode (GCE) were prepared by drop coating without a binder and utilized to study the electrochemistry of chlorpromazine (CPZ) in acidic, neutral and basic pHs. It appeared that (i) CPZ's electrochemical oxidation was a two‐step one‐electron process at SOD/GCE and a one‐step two‐electron process at SOD‐GF/GCE and (ii) the electrochemical reaction mechanism was an EEC mechanism at SOD/GCE while at SOD‐GF/GCE the mechanism was EEC at pH<4 and EC for greater pH. SOD/GCE and SOD‐GF/GCE were used to sense CPZ within CPZ's concentration ranging from 0.5‐30 μM with low detection limits.