Electrochimica Acta最新文献

{"title":"Electrodeposited polydopamine-polyethyleneimine films as permselective coatings for oxidase-based amperometric sensors","authors":"Kaina Wei, Sijie Niu, Xiaolin Cao, Aman Tang, Ziping Zhang","doi":"10.1016/j.electacta.2025.146571","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146571","url":null,"abstract":"Polydopamine and its composites are utilized as a versatile platform for enzyme immobilization in amperometric enzyme biosensors. While numerous studies have used the strong adhesion, good biocompatibility and easy modifiability of polydopamine-based composites for the fabrication of enzyme modified electrodes, no studies have demonstrated their ability as a permselective layer to eliminate interfering currents from common electroactive interferents of ascorbic acid, uric acid and acetaminophen. In this study, we demonstrate that polydopamine- polyethyleneimine (PDA-PEI) film electrodeposited on platinum (Pt) substrate electrode suppresses electrochemical oxidation currents of ascorbic acid, uric acid and acetaminophen while retains electrocatalytic activity of Pt substrate toward electro-oxidation of H₂O₂. Based on this permselective property of the PDA-PEI film, an amperometric enzyme biosensor for selective and sensitive detection of lactate was built by using electro-oxidation current of lactate oxidase enzymatically generated H₂O₂ as sensor signal. Analyte lactate was detected with a wide linear concentration range from 0.01 to 4.5 mM and a detection limit of 3.4 μM. The developed enzyme biosensor was also capable of detecting lactate in real samples with satisfactory recovery results. This study illustrates a new property of the polydopamine-based composites for application in amperometric enzyme biosensors and could be helpful for developing selective and sensitive electrochemical biosensors to detect other analytes.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"43 1","pages":"146571"},"PeriodicalIF":6.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fe3O4 nano-octahedra and SnO2 nanorods modifying low-Pd amount electrocatalysts for alkaline direct ethanol fuel cells","authors":"Tuani C. Gentil, Lanna E.B. Lucchetti, João Paulo C. Moura, Júlio César M. Silva, Maria Minichova, Valentín Briega-Martos, Aline B. Trench, Bruno L. Batista, Serhiy Cherevko, Mauro C. Santos","doi":"10.1016/j.electacta.2025.146576","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146576","url":null,"abstract":"This work describes the ethanol oxidation reaction (EOR) in alkaline medium using low-palladium nanoparticle electrocatalysts modified by Fe₃O₄ nano-octahedra and SnO₂ nanorods. Operation studies on an alkaline direct ethanol fuel cell (ADEFC) were conducted using the developed electrocatalysts, and stability studies were performed using the advanced scanning flow cell (SFC) technique coupled to inductively coupled plasma mass spectrometry (online SFC-ICP-MS). The EOR was catalyzed by single (Pd/C and commercial Pd/C Alfa Aesar) and by synthesized binary/ternary electrocatalysts, in which Fe₃O₄ and SnO₂ nanostructures partially replaced the high-cost noble metal. The PdFe₃O₄/C was identified as the most promising synthesized material in the electrochemical studies, exhibiting the highest mass activity (1426 mA mg⁻¹ Pd) by cyclic voltammetry (CV), followed by the binary PdSnO₂/C (1135 mA mg⁻¹ Pd), and by the ternary (1074 mA mg⁻¹ Pd). This enhancement was attributed to the bifunctional mechanism enabled by Fe₃O₄ and SnO₂, therefore reducing poisoning and improving the EOR. Moreover, the operating results revealed that PdFe₃O₄/C showed the highest power density among the synthesized materials (31 mW cm⁻² at 70°C), even with a ∼45% reduction in Pd content compared to the commercial. XPS results showed that the Pd 3d₅/₂ and 3d₃/₂ peaks for PdFe₃O₄/C, PdSnO₂/C, and PdFe₃O₄SnO₂/C were shifted by ∼0.5 eV to higher binding energies compared to Pd/C, indicating a loss of electron density in Pd due to strong metal–oxide interactions. These interactions led to a downward shift in the d-band center of Pd, weakening the Pd-adsorbed bonds, facilitating the desorption of intermediates, and improving the catalyst tolerance to toxic species. Furthermore, the higher proportion of Pd oxides in the binary and ternary materials appeared to contribute to the supply of oxygenated species required for the oxidation of EOR intermediates. Thus, the observed enhancement resulted from synergistic bifunctional and electronic effects. Finally, online SFC-ICP-MS studies showed that Fe₃O₄ nano-octahedra contribute to the enhanced stability of the electrocatalyst, as PdFe₃O₄/C exhibits reduced Pd dissolution and no Fe dissolution.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"148 1","pages":"146576"},"PeriodicalIF":6.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A dual Kalman filtering algorithm for estimating the state of charge and health of sodium-ion batteries based on adaptive strong tracking algorithm and schmidt orthogonal transformation","authors":"Jialian Chen, Zhipei Xu, Xu Qin, Fumin Zou, Xinjian Cai","doi":"10.1016/j.electacta.2025.146575","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146575","url":null,"abstract":"Sodium-ion batteries (SIBs) have emerged as a promising energy storage technology due to their simple structure, scalability, and cost-effectiveness, garnering significant attention in recent years. Accurate estimation of the state of charge (SOC) and state of health (SOH) is critical for optimizing battery management and ensuring operational reliability. This study proposes a new joint estimation framework for SOC and SOH in SIB, based on the adaptive strong tracking algorithm of the fractional-order model and the double Kalman filtering algorithm of schmidt orthogonal transformation (ASTSOUKF-EKF). By obtaining the initial values of each parameter through the whale optimization algorithm and conducting modeling, it is proved that the fractional-order model effectively captures the complex ion dynamics of SIBs, and the maximum modeling error is less than 0.0707 V. To address the challenges of voltage sensitivity limitations and real-time state tracking, we integrate the improved adaptive strong Tracking Filter (ASTF) with the Unscented Kalman Filter (UKF), and utilize an adaptive algorithm to re-determine the value of the fading factor by using the relationship between prior residuals and posterior residuals, thereby enhancing the SOC estimation accuracy and dynamic response. Schmidt orthogonal transformation (SOT) is further incorporated to streamline computational processes during sampling point selection, while the extended Kalman filter (EKF) enables robust online parameter identification for accurate SOH monitoring. Experimental validation under diverse health states demonstrates the algorithm's superior performance, achieving an average SOC error <0.4% and SOH accuracy within 1%, with maximum average errors of 0.58%. This work establishes a methodological foundation for advanced battery management in SIBs, bridging critical gaps between theoretical modeling and practical implementation for next-generation energy storage systems.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"5 1","pages":"146575"},"PeriodicalIF":6.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Moderately Solvating Electrolytes for Lithium−ion Batteries: Co−intercalation−free and Wide−Temperature","authors":"Junam Kim, Thuy Duong Pham, Seung-Hyeok Ma, Bouk Heo, Kyungwon Kwak, Kyung-Koo Lee","doi":"10.1016/j.electacta.2025.146573","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146573","url":null,"abstract":"Ether-based electrolytes offer significant advantages for fast-charging and low-temperature lithium-ion batteries (LIBs) due to their low viscosity and melting points. However, conventional ether solvents suffer from co-intercalation into graphite (Gr) electrodes, leading to irreversible damage. Herein, a moderately solvating electrolyte (MSE) consisting of 1.0 M lithium bis(fluorosulfonyl)imide (LiFSI) in 2-methoxy-1,3-dioxolane (2MeODOL) for LIBs is designed to overcome the issues associated with LIBs. Computational analyses demonstrate that 2MeODOL strikes a balance between strong and weak solvation, enhancing Li⁺ transport and desolvation while suppressing solvent co-intercalation into Gr anodes. In practical Gr||LFP full cells, the MSE with 1 wt% VC achieved stable cycling performance, delivering a specific capacity of 120 mAh g⁻¹ and maintaining 93% capacity retention after 250 cycles at a charge/discharge current density of 1.0 C. Moreover, this electrolyte demonstrated excellent low-temperature operability at −40°C, surpassing traditional carbonate-based electrolytes. This study introduces a design concept for ether solvents that optimizes solvation power and expands the working temperature window, offering a promising route for high-energy-density LIBs.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"5 1","pages":"146573"},"PeriodicalIF":6.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144165302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Silver Nano-particles Modification Used as Cathode Catalysts to Enhance Anion Exchange Membrane Fuel Cells","authors":"Fa-Cheng Su, Guan- Yu Chu, Hsiharng Yang","doi":"10.1016/j.electacta.2025.146544","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146544","url":null,"abstract":"This research mainly explores the non-precious metal catalyst used as in the cathode electrode to improve the anion exchange membrane fuel cell (AEMFC) performance. Because nano-silver particles with excellent oxygen reduction reaction (ORR) characteristics and lower cost compared to Pt, they are good candidates for cathode electrode in AEMFC. Two approaches can realize the target to use Ag instead of Pt. It was implemented with processing Ag nano-particle, the resulted cell performance close to Pt with 3.5% difference. The other one is to modify Ag surface using cerium nitrate to enhance cell performance. In the experiment, the pickling Vulcan XC72R carbon black was used to increase functional group of Vulcan XC72R carbon black attached on their surface. It also can increase Ag nano-particles to integrate with the cathode substrate. The silver nitrate was reduced to Ag nano-particles through a chemical process for the cathode. Combined with the reducing agent ammonium cerium nitrate and the N₂ gas environment during the annealing of the furnace tube, the cathode catalyst with 40 wt% Ag nano-particles were completed. While platinum (Pt/C) (40 wt%) was mixed with isopropanol (IPA) and deionized water (DI) with a certain ratio for the anode. It was found to be 7:3 (IPA, DI) mixed with Pt/C for the anode and then 5:5 (IPA: DI) mixed Ag/C for the cathode. Through this study, it was found that the highest cell performance reached 623 mW/cm². It can implement non-precious metal catalyst, Ag nano-particles, to be used as cathode for AEMFC.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"5 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual Z-scheme TiO₂/sugarcane bagasse biochar/MoS₂ heterojunction for enhanced visible-light photocatalysis and energy storage","authors":"Heba A. El-Sabban, Eman A. Motawea, Omnia A.A. El-Shamy, M.A. Deyab","doi":"10.1016/j.electacta.2025.146538","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146538","url":null,"abstract":"This article describes the preparation of TiO₂/MoS₂ combined with an exponentially efficient sugarcane bagasse biochar (SBB) using a simple hydrothermal method. It was practicable to efficiently establish an effective dual Z-scheme heterojunction by analyzing the band structure of the catalyst components. This resulted in an increased number of active sites, which expeditiously facilitates the separation of photo-generated species. The created ternary nanocomposite of TiO₂/SBB/MoS₂ underwent sequential characterizations. Additionally, research was done on the basic process governing the photodegradation of methylene blue dye (MB). The TiO₂/SBB/MoS₂ (T/SBB/M) ternary hybrid photocatalyst showed a much higher photocatalytic decay efficiency of 99.3% for the removal of 30 ppm methylene blue (MB) dye under visible-light irradiation in 40 min. As compared to pristine TiO₂ NPs, MoS₂ flowers, and binary TiO₂/MoS_2, which were only around 36.6 %, 50 %, and 82 %, respectively, keeping the irradiation time. The optimum dosage of T/SBB/M catalyst in this study was recorded to be 0.3 g/L with the highest K_a value (0.1193 min^-1). According to trapping experiments, •O2- and •OH species play the major part in the photo-catalytic oxidation process, while h+ species demonstrate a minimal role. Additionally, the catalyst continued to be reactive even after four reaction cycles. Furthermore, the produced composite was studied for the energy storage application of supercapacitors. The TiO₂/SBB/MoS₂ nanocomposite showed a capacitance of 656 F g^-1 at 1.0 A g^-1. Additionally, the TiO₂/SBB/MoS₂ nanocomposite electrode exhibited an impressive 93.5% capacity retention even after 5000 cycles.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"58 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptable design of parallel-leaf vein stratified flow field under different inlet and outlet arrangements in PEM fuel cells","authors":"Bin Wang, Weitong Pan, Zichao Hu, Longfei Tang, Xueli Chen, Fuchen Wang","doi":"10.1016/j.electacta.2025.146557","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146557","url":null,"abstract":"A well-designed flow field is crucial for the uniformity and output performance of Proton Exchange Membrane (PEM) fuel cells. Nevertheless, both manifold and transition zone designs have remained limitations, and a universal strategy for optimizing uniformity under different inlet and outlet conditions has not been developed. Therefore, a three-dimensional two-phase numerical model of PEM fuel cells is constructed in this work. A novel philosophy-stratified flow field-is proposed, derived from which symmetrical half and symmetric Parallel-Leaf Vein Stratified Flow Fields (PLVSFFs) are presented. Firstly, the transfer-reaction characteristics of PLVSFFs are elucidated. The symmetric half and symmetric designs facilitate reactant delivery from one side to the other and from both sides to the center, respectively. Secondly, the effects of different inlet and outlet arrangements, namely Left In-Left Out (LILO), Left in-Right Out (LIRO), and Left-Right In-Left-Right Out (LRILRO), are explored. Low reactant concentrations are observed in the right region, center, and center, respectively. Thirdly, the adaptable design is performed, with symmetric half, symmetric, and symmetric PLVSFFs applied to the three inlet and outlet layouts, respectively. Compared to the PFF, the output performance is enhanced by 30.70%, 8.17%, and 8.14%, while reactant uniformity is improved by 39.89%, 15.15%, and 16.71%, respectively. The drainage capability is also enhanced. The Parallel Flow Field (PFF) and Leaf Vein Flow Field (LVFF) play the roles of fundamental transport and optimized control, respectively. Finally, the superior impacts of this novel stratified flow field are validated via the application under different geometric and operational conditions and the evaluation of net output performance.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"239 1","pages":"146557"},"PeriodicalIF":6.6,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Corrosion Test Methods for Microstructure Screening of WAAM Duplex Stainless Steel","authors":"H.Z. Attar, Y. Zhou, M.J. Roy, J.W. Fellowes, V.A. Hossein, D.L. Engelberg","doi":"10.1016/j.electacta.2025.146564","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146564","url":null,"abstract":"Duplex stainless-steel type 2209 has been subjected to Wire + Arc Additive Manufacturing (WAAM) with varying heat input and interpass temperatures. This creates a non-equilibrium microstructure that negatively impacts corrosion resistance. Various electrochemical techniques have been applied to link microstructure to pitting corrosion resistance, particularly examining the austenite phase fraction and elemental content distribution in the obtained austenite and ferrite. It will be demonstrated that reducing heat input from 1.15 kJ/mm to 0.54 kJ/mm and lowering interpass temperature from 250°C to 150°C mitigates the formation of deleterious acicular austenite and significantly enhances pitting corrosion resistance, evidenced by higher critical pitting temperature and pit initiation potential. Locations closer to the arc-start and arc-termination points exhibited lower pitting resistance, underscoring the significant influence of deposition direction on microstructure heterogeneity and resulting corrosion resistance.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"7 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The clean production of low-oxygen titanium powder through molten salt electrolysis-magnesiothermic reduction (MSE-MR) of TiO2","authors":"Liguo Zhu ,&nbsp;Zuqing Zhang ,&nbsp;Lingxin Kong ,&nbsp;Baoqiang Xu ,&nbsp;Bin Yang","doi":"10.1016/j.electacta.2025.146478","DOIUrl":"10.1016/j.electacta.2025.146478","url":null,"abstract":"<div><div>The Kroll process is the primary method for the producing of titanium sponge. However, it is related to complex procedures, low efficiency and a large amount of energy use. A new method to produce low-oxygen titanium powder using molten salt electrolysis-magnesiothermic reduction (MSE-MR) TiO₂ in MgCl₂-KCl-YCl₃ molten salt was proposed, aiming at improving production efficiency and reducing costs. TiO₂ and graphite were used as the cathode and anode, respectively. The metal Mg was deposited on the TiO₂ cathode by electrodeposition, so that O was removed from TiO₂ in the form of oxygen ions (O^2-) into the molten salt (2Mg (in flux) + TiO₂(<em>s</em>) = Ti(<em>s</em>) + 2O^2-(in flux) + 2Mg²⁺ (in flux)). O^2- is removed from the system by forming YOCl (O^2- (in flux) + Y³⁺ (in flux) + Cl^- (in flux) = YOCl (<em>s</em>)) in the molten salt and CO<em>_x</em> (<em>x</em> = 1, 2) (<em>x</em>O^2- + C (<em>s</em>) = CO<em>_x</em> (<em>x</em> = 1, 2) (<em>g</em>) + 2<em>x</em>e^-) on the anode. The activity of O^2- (<span><math><msub><mi>a</mi><msup><mrow><mrow><mi>O</mi></mrow></mrow><mrow><mn>2</mn><mo>−</mo></mrow></msup></msub></math></span>) is notably decreased, which promotes Mg to remove O from titanium deeply. The results of the experiments show that titanium powder containing a content of oxygen of 360 ppm can be prepared by MSE-MR of TiO₂. The study describes a new method for producing low-oxygen titanium powder with an oxygen content of no more than 500 ppm. This approach offers several benefits, including a shorter processing time, reduced energy consumption, and lower emissions. It is expected to be applied in industry in the future and realize the clean production of Ti.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"533 ","pages":"Article 146478"},"PeriodicalIF":5.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-assisted synthesis of bifunctional multiphase Nickel Sulfide (Ni-S) and NiCo2S4 Electrocatalysts for water splitting","authors":"Ameer Ali, Syed Khalid, Sajid Butt, Syed Jazib Abbas Zaidi, Tae Joo Park, Muhammad Abdul Basit","doi":"10.1016/j.electacta.2025.146553","DOIUrl":"https://doi.org/10.1016/j.electacta.2025.146553","url":null,"abstract":"Water splitting into hydrogen and oxygen with non-noble and efficient electrocatalysts is crucial for green energy demands. The transitional metal-based sulfides are owing to the interest due to their high activity in electrochemical processes, low cost, and earth abundance. Herein, we report the bi-functional catalytic performance of multiphase Nickel Sulfide NiS₂ and Ni₉S₈ (Ni-S) and Nickel Cobalt Sulfide (NiCo₂S₄), synthesized with the one-step microwave-assisted (MWA) method, for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The flower-like nanosheets of Ni-S show effective HER performance at a low overpotential 152 mV at 50 mA cm^-2, because of the surface morphology and electron adsorption ability. Furthermore, the bimetallic nanospheres of NiCo₂S₄ give a high current density of 160 mA.cm^-2 at 275 mV overpotential for OER, because of the incorporation of nickel and cobalt species by stabilizing the sulfur phase for further improved activity and charge transfer capacity. Moreover, the NiCo₂S₄ has faster reaction kinetics with a low Tafel slope of 76 mV dec^-1 for OER and 37 mV dec^-1 for HER, rather than the Ni-S at 167 mV dec^-1 and 65 mV dec^-1 respectively.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"24 1","pages":"146553"},"PeriodicalIF":6.6,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144145950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}