Electrochimica Acta最新文献

{"title":"Development of heterostructured ZnCo2O4@Ni-MOF electrode for the asymmetric supercapacitor and electrocatalytic oxygen evolution reaction applications","authors":"Gita B. Bhanuse, Sanath Kumar, Cheng-We Chien, Yen-Pei Fu","doi":"10.1016/j.electacta.2024.145371","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145371","url":null,"abstract":"The stable structure and material combination design significantly improve the performance of electrochemical energy storage and water splitting. In the present study, we developed a ZCO@Ni-MOF core-shell structure over a nickel foam electrode, which is synthesized through a two-step hydrothermal treatment. The developed material is comprehensively analyzed to confirm structural, chemical, electronic, surface, and morphological characteristics using X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscope (SEM), and transmission electron microscope (TEM). Electrochemical investigations using a three-electrode system revealed that ZCO@Ni-MOF demonstrated an impressive specific capacitance of 1800 F g⁻¹ at a current density of 2 A g⁻¹ in a 1 M KOH electrolyte. The electrochemical findings are consistent across various electrochemical techniques. Furthermore, in-depth studies regarding p-n junction formation, interlayer spacing, and reaction kinetics studies are briefly analyzed with Mott-Schottky, Ex-situ XRD, and operando impedance studies. Moreover, an asymmetric supercapacitor (ASC) is assembled with ZCO@Ni-MOF as the positive electrode and activated carbon as the negative electrode in a Swagelok cell. This configuration demonstrated an energy density of 13.6 Wh kg⁻¹ at a power density of 225 W kg⁻¹. The ASC exhibited performance by retaining 91% of its initial capacity even after 1500 cycles. For practical demonstration, two ASCs are fabricated and assembled in series to light up an LED, and the light-up duration is analyzed. For the oxygen evolution reaction (OER) study, the ZCO@Ni-MOF-based electrode exhibited activity with a lower overpotential of 340 mV (50 mA cm⁻²) in an alkaline environment and was responsible for stability for about 10 h. This combination reiterates the promising material aspects in energy storage and conversion devices, instilling hope for its potential applications.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"12 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665313","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":"Hydrothermal Synthesis of Rose Bengal Dye Particle Deposition on Layered Reduced Graphene Oxide Composite for Photo Assisted Supercapacitor Applications","authors":"Suresh D S, Sapna Sharanappa, Vijaykumar S P, Abdullah Ba Shbil, Ganesha H, Devendrappa H","doi":"10.1016/j.electacta.2024.145380","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145380","url":null,"abstract":"Cutting-edge application of Photo-supercapacitor (PSC) in optoelectronics from photo-electrochemical storage electrode with energy conversion generating revolutionary shift to novel energy storage devices. The maximum absorbance of Rose Bengal (RB) at 547 nm gives the Power Conversion Efficiency (PCE) of Dye Sensitized Solar Cell (DSSC) is 0.34%. The fusion of RB with reduced Graphene Oxide (rGO) in aqueous and organic environment solubility provides functionalization of oxygen groups modifies surface wettability and mobility of Rose Bengal-reduced Graphene Oxide (RB-rGO) composite. It also provides structural transformation of amorphous RB into poly-crystalline RB-rGO composite and morphology studies confirm that large surface area of condensed layers of rGO grains incorporated with circular plates of RB provides maximum specific capacitance was 672 F/g and capacitance retention is 82.5% across 4000 Galvanostatic Charging and Discharging (GCD) cycles. The highest energy and power density are achieved by RB-rGO's Electric Double Layer Capacitance (EDLC) mechanism yields 38.88 Whr/kg and 4.988 kW/kg respectively. The PSC evident from self-charging capacitor improved specific capacitance of Galvanostatic charging and discharging (GCD) from 179 to 483 F/g and Cyclic Voltammetry (CV) from 285 to 503 F/g respectively under the influence of light that can enhances surface adsorption and charge transfer kinetics.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"21 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665320","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":"Arylether-type polybenzimidazole-based composites containing imidazole-substituted heteropolyacid salts for high-temperature proton exchange membrane fuel cells","authors":"Jiayu Yang, Chengying Shi, Jingwei Li, Tianyang Li, Hui Zhang, Qingxin Chen, Peng Wang, Wei Hu, Baijun Liu","doi":"10.1016/j.electacta.2024.145368","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145368","url":null,"abstract":"Phosphoric acid-doped polybenzimidazole (PA-PBI) membranes are one of the most promising candidates for practical applications in high temperature proton exchange membrane fuel cells. In the field of the proton exchange membranes, a key target is to develop the membranes possessing high proton conducting ability, and meanwhile maintaining good mechanical integrity. It is extremely hard for PBI-based membranes at a high acid doping level (ADL) to have good strength due to the strong “plasticization effect” caused by PA molecules to PBI backbones. In order to obtain high-proton-conductivity membranes with a good comprehensive performance, three imidazole-substituted heteropolyacid salts (imi-HPAs) were synthesized and then incorporated into an arylether-type polybenzimidazole (Ph-PBI) matrix to fabricate some composite membranes via a solution blending process. Since both Ph-PBI matrix and imidazole-substituted heteropolyacid salts contained the functional imidazole groups, some preferred mixed effects and performance enhancements of the organic-inorganic composite membranes were observed. The morphology of the composite membranes revealed that imidazole-substituted heteropolyacid salts were homogenously dispersed in the Ph-PBI matrix. The membrane Ph-PBI/imi-HPA-3-15% at ADL∼290.4% had the highest conductivity of 166.6 mS·cm^-1 at 200 °C. A H₂/O₂ fuel cell based on one membrane showed a peak power density of 454 mW·cm^-2 at 160 °C, without humidification.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"46 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645907","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":"Electron Transport in Heteroatom-Doped Graphene Quantum Dots for TiO2-based Dye-sensitized Solar Cells","authors":"Savisha Mahalingam, Ramisha Rabeya, Abreeza Manap, Kam Sheng Lau, Chin Hua Chia, Nurfanizan Afandi, Azimah Omar","doi":"10.1016/j.electacta.2024.145369","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145369","url":null,"abstract":"Graphene quantum dots (GQDs) hold promise as co-sensitizers in dye-sensitized solar cells (DSSCs) due to their excellent light-harvesting capabilities. However, their intrinsic limitations in electron transport can hinder overall device performance. This study investigates the impact of heteroatom-doping with nitrogen (N), fluorine (F), and sulfur (S) on the performance of GQDs as co-sensitizers for N719 dye in DSSCs. The heteroatom-doped GQDs (NFS-GQDs) enhance light harvesting compared to pristine GQDs, extending absorption into the UV region. Photoluminescence quenching data confirms efficient electron injection from both GQDs and NFS-GQDs to the TiO₂ conduction band, exhibiting superior electron injection efficiency. Among the co-sensitized cells, 20 wt.% doping level achieves the highest power conversion efficiency of 4.33 %. Besides, electron transport and electronic structure were investigated in detail to understand the interaction of the TiO₂/NFS-GQDs+N719 interface. The findings suggest that NFS-doping GQDs offer a promising strategy for developing efficient co-sensitizers for DSSCs.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"26 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645904","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":"Investigating the synergistic characteristics of air processable CsPbIBr₂ perovskite electrodes for solar cell and energy storage applications","authors":"Sajid Khan, Muhammad Zahir Iqbal, Nacer Badi, Ahmed M. Fouda, H.H. Hegazy","doi":"10.1016/j.electacta.2024.145372","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145372","url":null,"abstract":"Mixed halide perovskite materials exhibited excellent optoelectronic, ionic, and electronic properties, extending the possibility of introducing them as an efficient electrode material for energy storage and conversion applications. In this work, we performed the synthesis of CsPbIBr₂ in ambient conditions and investigated its characteristics for solar cells and energy storage devices. The X-ray diffraction (<em>XRD</em>) technique is employed for the structural characterization of the as-synthesized perovskite crystals. The optical bandgap of ⁓ 2.1 eV is revealed utilizing <em>UV-Vis</em>, photoluminescence (<em>PL</em>), and diffuse reflectance (<em>DR</em>) spectroscopies. The photovoltaic performance of the as-synthesized CsPbIBr₂ perovskite for solar cell devices is initially tuned by varying precursor solution quantity to obtain the optimum performance. The optimized <em>PCE</em> of 6.2% is achieved for the device without a hole transport layer (<em>HTL</em>) and with carbon as the counter electrode. Impedance spectroscopy (<em>IS</em>) is employed to investigate the impact of solution quantity on interfacial charge transport kinetics. Further, the electrochemical properties of the perovskite are elucidated by analyzing cyclic voltammetry (<em>CV</em>) voltammograms, and galvanostatic charge-discharge (<em>GCD</em>) curves recorded at different scan rates and current densities, respectively. The specific capacity of 570 C/g is recorded under dark conditions. Our findings demonstrate the dual applications of the perovskites and will pave a pathway to develop new potential electrode materials based on perovskite for energy conversion and storage devices.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"76 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665316","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":"An open source electrochemical channel flow cell setup for kinetics studies. Application to investigations on oxygen electrocatalysis.","authors":"Alessandro Brega, Sylvain Brimaud","doi":"10.1016/j.electacta.2024.145365","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145365","url":null,"abstract":"Herein, an electrochemical channel flow cell setup that allows for conducting electrochemical investigations up to 80°C and pressurized gases up to 3 bar is presented in details, including technical drawings and list of parts, in an attempt to facilitate the adoption of such setup by the community for electrochemical/electrocatalytic kinetic studies. The oxygen reduction reaction (ORR) on a commercial Pt/C catalyst, chosen as a model reaction, was investigated to demonstrate the reliability of the experimental setup, including the hydrodynamic properties, to provide hands on practical guidelines to carry out experiments, and, on the other hand, to illustrate the capabilities of this electrochemical setup for an assessment of basic quantities. Among the various quantities that have be determined experimentally for the ORR, a monotonic decay of the activation enthalpy and bell-shaped variation of the entropy of activation were resolved as the overpotential for the ORR increases. These fundamental thermodynamic/kinetic data are briefly discussed within the frame of the established reaction mechanism and can serve as a feed for the benchmarking of the outputs from theoretical/computational models. Furthermore, a remarkable agreement was obtained between the change in the activation free Gibbs energy determined for the ORR with the flow cell setup and the kinetic region of fuel cell polarization curve obtained with the same Pt/C catalyst embedded in the cathode of an a hydrogen proton exchange membrane fuel cell. This enables potentially a bridge of the environmental gap existing between model experiments conducted at active material level in contact with liquid electrolyte and experiments with porous gas diffusion electrode embedding the same active material that are employed in practical device.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"32 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645905","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":"On the semi-infinite distributed resistor-constant phase element transmission line","authors":"Anis Allagui, Enrique H. Balaguera","doi":"10.1016/j.electacta.2024.145344","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145344","url":null,"abstract":"Under a particular geometrical arrangements of impedances of the type resistors and capacitors for the modeling of a transmission line, the voltage and current along the line are known to follow the standard partial differential equation of diffusion. In this work we propose a generalization of this circuit network by considering the non-ideal fractional capacitive element, also known as constant phase element (CPE), as the energy storage component. The CPE’s impedance is given by &lt;span&gt;&lt;span&gt;&lt;math&gt;&lt;mrow is=\"true\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;Z&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow is=\"true\"&gt;&lt;mo is=\"true\"&gt;(&lt;/mo&gt;&lt;mi is=\"true\"&gt;s&lt;/mi&gt;&lt;mo is=\"true\"&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo is=\"true\" linebreak=\"goodbreak\" linebreakstyle=\"after\"&gt;=&lt;/mo&gt;&lt;mn is=\"true\"&gt;1&lt;/mn&gt;&lt;mo is=\"true\"&gt;/&lt;/mo&gt;&lt;mrow is=\"true\"&gt;&lt;mo is=\"true\"&gt;(&lt;/mo&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msup is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo is=\"true\"&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;&lt;script type=\"math/mml\"&gt;&lt;math&gt;&lt;mrow is=\"true\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;Z&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow is=\"true\"&gt;&lt;mo is=\"true\"&gt;(&lt;/mo&gt;&lt;mi is=\"true\"&gt;s&lt;/mi&gt;&lt;mo is=\"true\"&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo linebreak=\"goodbreak\" linebreakstyle=\"after\" is=\"true\"&gt;=&lt;/mo&gt;&lt;mn is=\"true\"&gt;1&lt;/mn&gt;&lt;mo is=\"true\"&gt;/&lt;/mo&gt;&lt;mrow is=\"true\"&gt;&lt;mo is=\"true\"&gt;(&lt;/mo&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msup is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo is=\"true\"&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/script&gt;&lt;/span&gt;, where &lt;span&gt;&lt;span&gt;&lt;math&gt;&lt;mrow is=\"true\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo is=\"true\" linebreak=\"goodbreak\" linebreakstyle=\"after\"&gt;&gt;&lt;/mo&gt;&lt;mn is=\"true\"&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;&lt;script type=\"math/mml\"&gt;&lt;math&gt;&lt;mrow is=\"true\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo linebreak=\"goodbreak\" linebreakstyle=\"after\" is=\"true\"&gt;&gt;&lt;/mo&gt;&lt;mn is=\"true\"&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/script&gt;&lt;/span&gt; and &lt;span&gt;&lt;span&gt;&lt;math&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;0&lt;/mn&gt;&lt;mo is=\"true\" linebreak=\"goodbreak\" linebreakstyle=\"after\"&gt;&lt;&lt;/mo&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;mo is=\"true\" linebreak=\"goodbreak\" linebreakstyle=\"after\"&gt;⩽&lt;/mo&gt;&lt;mn is=\"true\"&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;&lt;script type=\"math/mml\"&gt;&lt;math&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;0&lt;/mn&gt;&lt;mo linebreak=\"goodbreak\" linebreakstyle=\"after\" is=\"true\"&gt;&lt;&lt;/mo&gt;&lt;mi is=\"true\"&gt;α&lt;/mi&gt;&lt;mo linebreak=\"goodbreak\" linebreakstyle=\"after\" is=\"true\"&gt;⩽&lt;/mo&gt;&lt;mn is=\"true\"&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/script&gt;&lt;/span&gt;, and offers an extra degree of freedom compared to the ideal capacitor of impedance &lt;span&gt;&lt;span&gt;&lt;math&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;Z&lt;/mi&gt;&lt;mo is=\"true\" linebreak=\"goodbrea","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"8 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645906","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":"Pitfall on the interpretation of double layer capacitance increase after accelerated stress test of hydrogen evolution reaction on NiMo catalysts","authors":"Abdul Majeed, Nicholas Hemmerling, Bastian J.M. Etzold","doi":"10.1016/j.electacta.2024.145358","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145358","url":null,"abstract":"Critical investigation of methods used to screen the catalytic activity of different electrocatalysts is crucial for the development of water electrolysis technology. One of such protocols to justify the catalytic activity trend among different catalysts involves determining their electrochemically active surface area (ECSA) which is usually estimated from non-Faradic double layered capacitance (C_dl) of the catalyst material. Furthermore, catalytic current normalized with ECSA is frequently used to gain insight into the intrinsic activity of a catalyst. Since not all the metallic catalysts are highly stable under the electrolysis conditions, it is highly important, though rarely explored, to investigate whether or not the adsorption/desorption of leached/dissolved multivalent metal ions influences the measurement of non-Faradic C_dl. Here, we explore the possible influence of Mo leached from NiMo alloy on the measured C_dl of NiMo. Using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), C_dl of NiMo alloy was measured before and after carrying out long term (chronopotentiometric and CV cycling) hydrogen evolution reaction (HER) in alkaline conditions. After extended HER testing, we observe a notable rise (∼22% averaging all our experiments) in the C_dl of NiMo alloy when measured with traditional methods. Interestingly, only 8% of this increase can be attributed to an expansion in surface area. We hypothesize that the majority of the increase in C_dl stems from the higher amount of charges stored through leached multivalent ions, which accumulate within surface cavities.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665269","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":"Glucose electrooxidation on carbon supported NiAu electrocatalysts","authors":"Weliton Silva Fonseca, Thibault Rafaïdeen, Hamza Kahri, Têko W. Napporn, Christophe Coutanceau","doi":"10.1016/j.electacta.2024.145367","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145367","url":null,"abstract":"NiAu/C nanomaterials are synthesised using a wet chemistry method with targeted Au atomic ratios of 10%, 20% and 30%. Physicochemical characterisations indicate that the materials have mean compositions close to the nominal ones but ca. 20 at% Au richer in average than expected (Au ratios of 13.6 at%, 23.1 at% and 35.9 at%, respectively). The NiAu/C materials are composed of Au-rich spherical-like Janus particles of several tenths nm and of a phase of very small Ni-rich nanoparticles and Ni(OH₂) clusters. The electrochemical measurements in a 0.1 M NaOH/0.1 M glucose electrolyte indicate that the NiAu20/C catalyst is the most active for the glucose oxidation reaction, leading to a mass activity at +0.6 V vs RHE more than 1.5 times higher than that with a pure Au/C catalyst, although the Au content is almost 5 times lower. The chronoamperometry measurements for 900 s at +0.6 V vs RHE confirm the activity gain with the NiAu20/C catalyst. The electrolysis measurement at a cell voltage of +Z+0.6 V for 6 hours shows that the NiAu20/C catalyst is selective towards the production of gluconic acid, with a faradaic efficiency higher than 100%, indicating the occurrence of a 1-electron reaction with anodic hydrogen coproduction. At +0.8 V, the faradaic efficiency is lower than 100 %, indicating the formation of other products than gluconic acid, but at a very low extent (not detectable by HPLC) guarantying a very high selectivity towards gluconic acid.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"50 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665270","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":"Voltammetric detection with a comprehensive electrochemistry study of minoxidil using nuclear magnetic resonance and infrared analyses: Applications in the forensic and pharmaceutical fields.","authors":"Anne A. Macedo, Dilton M. Pimentel, Amanda N. de Souza, Higor M. Mundim, Luciano M. Lião, Lívia M.F. Costa, Rodrigo Moreira Verly, Wallans T.P. dos Santos","doi":"10.1016/j.electacta.2024.145362","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145362","url":null,"abstract":"Minoxidil (MN) is a vasodilator used to treat hair loss and severe hypertension. However, its illegal use in cosmetics and pharmaceutical formulations has been reported in several countries. An efficient method for MN detection is of great interest for forensic and pharmaceutical applications. Electrochemical sensors have been reported as an interesting alternative for MN detection in various samples. However, a more in-depth study of the redox processes and a more selective electrochemical detection for MN are still required. In this context, we present, for the first time, the use of nuclear magnetic resonance and Fourier transform infrared spectroscopy analyses for understanding the electrochemical behaviour of MN after electrolysis procedures on a boron-doped diamond electrode (BDDE). Using these combined techniques, we have proposed and confirmed an electrochemical mechanism for all redox processes of MN on a BDDE, where in phosphate buffer (pH 6.0) two oxidation processes at +0.72 V and +0.97 V vs (Ag/AgCl/ sat. KCl) are presented. The last generated product by MN oxidation is reduced on the BDDE surface at -0.01 V with a quasi-reversible redox process. The use of this redox process is the strategy for a selective and sensitive detection of MN on the BDDE. This innovative approach was successfully applied to determine MN in adulterated cosmetics and pharmaceutical formulations, showing a low limit of detection (5.7 µmol. L^-1) and high stability of electrochemical responses (RSD &lt; 1.5 %, n = 6) using the same BDDE. Therefore, the proposed method provides a simple, fast and selective method for the identification and quantification of MN in pharmaceutical and forensic samples.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642669","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}