Pub Date : 2024-11-15DOI: 10.1016/j.electacta.2024.145360
Mirjam Rogler, Richard Wagner, Simon Thiele, Michel Suermann
This paper critically evaluates three methods for determining metrics of the oxygen evolution reaction (OER) describing the performance and stability of low-loading iridium-based anode catalyst layers (CLs) in proton exchange membrane water electrolysis (PEMWE) cells. The methods applied are OER mass activity, voltage breakdown analysis (VBA), and constant Tafel slope VBA (CT-VBA). They are used to assess the OER metrics as a function of anode CL configurations, potential cycling, and level of degradation. Therefore, various accelerated stress tests (ASTs) are carried out for a targeted degradation of different anode CLs based on Ir black or Ir oxide. It turns out that the OER mass activity method is robust, straightforward and an ideal method for e.g., in-house screening tasks. On the other hand, the VBA method is suitable for comparative analysis across laboratories by distinguishing between the three main overpotentials. The CT-VBA method, however, offers improved accuracy, as it accounts for mass transport overpotential at low current density, and is particularly suitable for determining apparent exchange current density values further used in modelling approaches. This benefit comes with a drawback, as commonly accepted reference Tafel slopes for respective catalyst type and PTL configurations would be required within the PEMWE community. This guidance therefore helps to choose the right method for determining OER metrics depending on the research question.
本文对描述质子交换膜水电解（PEMWE）电池中低负载铱基阳极催化剂层（CL）性能和稳定性的氧进化反应（OER）指标的三种测定方法进行了严格评估。应用的方法包括 OER 质量活度、电压击穿分析 (VBA) 和恒定塔菲尔斜率 VBA (CT-VBA)。这些方法用于评估 OER 指标与阳极 CL 配置、电位循环和降解程度的函数关系。因此，对基于黑铱或氧化铱的不同阳极 CL 进行了各种加速应力测试 (AST)，以实现有针对性的降解。结果表明，OER 质量活度法既稳健又简单，是内部筛选等任务的理想方法。另一方面，VBA 方法通过区分三种主要过电势，适用于不同实验室之间的比较分析。不过，CT-VBA 方法的准确性更高，因为它考虑了低电流密度下的质量传输过电位，特别适合确定表观交换电流密度值，并进一步用于建模方法。但这一优点也有缺点，因为 PEMWE 社区需要针对各自的催化剂类型和 PTL 配置提供公认的参考塔菲尔斜率。因此，本指南有助于根据研究问题选择正确的方法来确定 OER 指标。
{"title":"Guidance for targeted degradation analysis of OER kinetics of low-loading iridium-based catalysts in PEM water electrolysis cells","authors":"Mirjam Rogler, Richard Wagner, Simon Thiele, Michel Suermann","doi":"10.1016/j.electacta.2024.145360","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145360","url":null,"abstract":"This paper critically evaluates three methods for determining metrics of the oxygen evolution reaction (OER) describing the performance and stability of low-loading iridium-based anode catalyst layers (CLs) in proton exchange membrane water electrolysis (PEMWE) cells. The methods applied are OER mass activity, voltage breakdown analysis (VBA), and constant Tafel slope VBA (CT-VBA). They are used to assess the OER metrics as a function of anode CL configurations, potential cycling, and level of degradation. Therefore, various accelerated stress tests (ASTs) are carried out for a targeted degradation of different anode CLs based on Ir black or Ir oxide. It turns out that the OER mass activity method is robust, straightforward and an ideal method for e.g., in-house screening tasks. On the other hand, the VBA method is suitable for comparative analysis across laboratories by distinguishing between the three main overpotentials. The CT-VBA method, however, offers improved accuracy, as it accounts for mass transport overpotential at low current density, and is particularly suitable for determining apparent exchange current density values further used in modelling approaches. This benefit comes with a drawback, as commonly accepted reference Tafel slopes for respective catalyst type and PTL configurations would be required within the PEMWE community. This guidance therefore helps to choose the right method for determining OER metrics depending on the research question.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"25 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637833","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}
Pub Date : 2024-11-15DOI: 10.1016/j.electacta.2024.145347
Zhi Liu , Ningning Chen , Wanying Guo , Yinshuang Pang , Nailu Shen , Hong Chen , Wanying Zhang , Feichang Feng , Jingxiang Zhao , Yanyu Liang
Carbon-based materials are commonly used as anodes for potassium-ion batteries due to their high conductivity and stable cycling performance. However, their practical application is greatly hindered by their low capacity. Herein, we introduce facile sulfur chemistry including thioether bonds and CoS₂ into a nitrogen-oxygen co-doped partially graphitized carbon skeleton (NOGC), while the extra reconfiguration process of carbon assists forming the CoS₂@R-NOGC composites. The reconfigured NOGC (R-NOGC), enriched with highly electronegative elements (N, O, S), significantly enhances the reversible potassium ion storage capacity. The ordered carbon structure provides more efficient ionic transport pathways, thereby improving K⁺ transport efficiency. Moreover, layered CoS₂ acts as additional ion transport channels and active sites, further enhancing ion mobility and storage capacity. R-NOGC also promotes the reconstruction and repair of the solid electrolyte interface (SEI) layer to form a more robust interface. As a result of the synergistic effect between R-NOGC and CoS₂, it exhibits excellent anode performance, including a high reversible capacity (314.0 mAh/g at 0.1 A/g) and long-term stability (250.3 mAh/g at 0.5 A/g after 1,000 cycles). This work presents a novel strategy for designing and synthesizing high-performance anode materials for potassium-ion batteries, significantly enhancing both capacity and cycling stability.
{"title":"Facile sulfur chemistry assisted carbon reconfiguration for efficient potassium ion electrochemical storage","authors":"Zhi Liu , Ningning Chen , Wanying Guo , Yinshuang Pang , Nailu Shen , Hong Chen , Wanying Zhang , Feichang Feng , Jingxiang Zhao , Yanyu Liang","doi":"10.1016/j.electacta.2024.145347","DOIUrl":"10.1016/j.electacta.2024.145347","url":null,"abstract":"<div><div>Carbon-based materials are commonly used as anodes for potassium-ion batteries due to their high conductivity and stable cycling performance. However, their practical application is greatly hindered by their low capacity. Herein, we introduce facile sulfur chemistry including thioether bonds and CoS₂ into a nitrogen-oxygen co-doped partially graphitized carbon skeleton (NOGC), while the extra reconfiguration process of carbon assists forming the CoS₂@R-NOGC composites. The reconfigured NOGC (R-NOGC), enriched with highly electronegative elements (N, O, S), significantly enhances the reversible potassium ion storage capacity. The ordered carbon structure provides more efficient ionic transport pathways, thereby improving K⁺ transport efficiency. Moreover, layered CoS₂ acts as additional ion transport channels and active sites, further enhancing ion mobility and storage capacity. R-NOGC also promotes the reconstruction and repair of the solid electrolyte interface (SEI) layer to form a more robust interface. As a result of the synergistic effect between R-NOGC and CoS₂, it exhibits excellent anode performance, including a high reversible capacity (314.0 mAh/g at 0.1 A/g) and long-term stability (250.3 mAh/g at 0.5 A/g after 1,000 cycles). This work presents a novel strategy for designing and synthesizing high-performance anode materials for potassium-ion batteries, significantly enhancing both capacity and cycling stability.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"509 ","pages":"Article 145347"},"PeriodicalIF":5.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637647","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}
Pub Date : 2024-11-15DOI: 10.1016/j.electacta.2024.145359
José A. Tamayo, Carolina Ramírez-Sánchez, Jorge A. Calderón
The electrochemical behavior of ammoniacal thiosulfate solutions (S2O32-- NH3-Cu2+ -EDTA) has been studied for varying electrolyte compositions in the gold electro-dissolution. A gold rotating disk electrode (RDE) was employed to measure anodic and cathodic polarization curves in alkaline thiosulfate solutions. Potentiodynamic polarization showed how thiosulfate, ammonia, and copper concentration influence the cathodic and anodic behavior of the electrolyte. Likewise, the influence of oxygen on the electrochemical behavior system was evidenced from the analysis of polarization curves, and using Koutecky – Levich equation (slope of 59.60 mV/decade), it was possible to determine the peroxide pathway for oxygen reduction reaction (ORR) with two-electron transference. Additionally, gold dissolution and thiosulfate degradation were evaluated using the gold foil leaching tests. It was found solutions with a 0.2 mol L-1 thiosulfate concentration favored the dissolution of gold and by maintaining an adequate ratio between thiosulfate/ammonium (1:3) or thiosulfate/copper (4:1) enable the attainment high gold dissolution and lower degradation of thiosulfate.
{"title":"Effect of ammoniacal thiosulfate solution composition on the gold dissolution rate: An electrochemical study","authors":"José A. Tamayo, Carolina Ramírez-Sánchez, Jorge A. Calderón","doi":"10.1016/j.electacta.2024.145359","DOIUrl":"https://doi.org/10.1016/j.electacta.2024.145359","url":null,"abstract":"The electrochemical behavior of ammoniacal thiosulfate solutions (S<sub>2</sub>O<sub>3</sub><sup>2-</sup>- NH3-Cu<sup>2+</sup> -EDTA) has been studied for varying electrolyte compositions in the gold electro-dissolution. A gold rotating disk electrode (RDE) was employed to measure anodic and cathodic polarization curves in alkaline thiosulfate solutions. Potentiodynamic polarization showed how thiosulfate, ammonia, and copper concentration influence the cathodic and anodic behavior of the electrolyte. Likewise, the influence of oxygen on the electrochemical behavior system was evidenced from the analysis of polarization curves, and using Koutecky – Levich equation (slope of 59.60 mV/decade), it was possible to determine the peroxide pathway for oxygen reduction reaction (ORR) with two-electron transference. Additionally, gold dissolution and thiosulfate degradation were evaluated using the gold foil leaching tests. It was found solutions with a 0.2 mol L<sup>-1</sup> thiosulfate concentration favored the dissolution of gold and by maintaining an adequate ratio between thiosulfate/ammonium (1:3) or thiosulfate/copper (4:1) enable the attainment high gold dissolution and lower degradation of thiosulfate.","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"38 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637831","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}
Pub Date : 2024-11-13DOI: 10.1016/j.electacta.2024.145352
Hossein Esfandian, Mohammad Mojtaba Sadeghi
In this study, various mixed-linker metal-organic frameworks (MOFs) based on Zn-MOF were successfully synthesized using different ratios of 1,3,5-benzenetricarboxylic acid (BTC) and 1,4-benzenedicarboxylic acid (BDC) as modulator ligands. The characterization results indicated that a lower percentage of BDC ligand effectively enhances the specific surface area of the MOFs while maintaining their microporous structure. Furthermore, the supercapacitive behavior of the synthesized Zn-MOFs with varying mixed ligand ratios was evaluated through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge-discharge (GCD) measurements in a 6 M KOH electrolyte. Synthesized materials, namely MOF-0 (100 % BTC), MOF-1 (75 % BTC, 25 % BDC), MOF-2 (50 % BTC, 50 % BDC), MOF-3 (25 % BTC, 75 % BDC), and MOF-4 (100 % BDC) were assessed through GCD tests. These tests demonstrated specific capacitance values of 577, 683, 529, 428, and 302 F/g at a current density of 0.5 A/g, respectively. This impressive performance underscores the effectiveness of the mixed-linker strategy in optimizing the electrochemical properties of MOF for energy storage applications.
{"title":"Preparation and application of mixed ligand Zn-MOF as electrode materials for supercapacitors applications","authors":"Hossein Esfandian, Mohammad Mojtaba Sadeghi","doi":"10.1016/j.electacta.2024.145352","DOIUrl":"10.1016/j.electacta.2024.145352","url":null,"abstract":"<div><div>In this study, various mixed-linker metal-organic frameworks (MOFs) based on Zn-MOF were successfully synthesized using different ratios of 1,3,5-benzenetricarboxylic acid (BTC) and 1,4-benzenedicarboxylic acid (BDC) as modulator ligands. The characterization results indicated that a lower percentage of BDC ligand effectively enhances the specific surface area of the MOFs while maintaining their microporous structure. Furthermore, the supercapacitive behavior of the synthesized Zn-MOFs with varying mixed ligand ratios was evaluated through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge-discharge (GCD) measurements in a 6 M KOH electrolyte. Synthesized materials, namely MOF-0 (100 % BTC), MOF-1 (75 % BTC, 25 % BDC), MOF-2 (50 % BTC, 50 % BDC), MOF-3 (25 % BTC, 75 % BDC), and MOF-4 (100 % BDC) were assessed through GCD tests. These tests demonstrated specific capacitance values of 577, 683, 529, 428, and 302 F/g at a current density of 0.5 A/g, respectively. This impressive performance underscores the effectiveness of the mixed-linker strategy in optimizing the electrochemical properties of MOF for energy storage applications.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"509 ","pages":"Article 145352"},"PeriodicalIF":5.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601802","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}
Aluminum-tantalum powders are emerging as new raw materials for additive manufacturing (AM) technologies, but their preparation in bulk quantities and in powder form via conventional metallurgical methods is challenging. In this study, we report a one-step synthesis of spherical Al3Ta powder by direct electrolyzing solid Ta2O5 cathode (vs. a graphite anode) in molten Na3AlF6-K3AlF6-AlF3-LiF-Al2O3. Cyclic voltammetry and constant potential electrolysis techniques were employed to characterize the electrochemical reaction process, along with X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for the structural and morphological analyses. The process involves an initial Ta2O5 electro-deoxygenation process, the subsequent electrodeposition of Al3+ on the formed Ta particles and an in-situ alloying process. The innovative use of Ta2O5 cathodes with a novel hierarchical porous structure allows for a controlled transformation of cathode particle morphology and facilitates the rapid generation of nanoscale tantalum particles. Al3+ from the electrolyte is then electrodeposited onto these particles, initiating an in-situ alloying reaction. This is an exothermic process that facilitates the diffusion of aluminum atoms into tantalum, and reduces the interfacial energy promoting the formation of spherical Al3Ta particles. Such powders are in demand for AM techniques. The findings may now guide the way to establishing the electrochemical route for the short-process preparation of other high-temperature alloy powders.
铝钽粉末正在成为增材制造（AM）技术的新型原材料，但通过传统冶金方法制备大量粉末状铝钽粉末具有挑战性。在本研究中，我们报告了通过在熔融 Na3AlF6-K3AlF6-AlF3-LiF-Al2O3 中直接电解固体 Ta2O5 阴极（相对于石墨阳极）一步合成球形 Al3Ta 粉末的方法。采用循环伏安法和恒电位电解技术来表征电化学反应过程，并用 X 射线衍射 (XRD)、扫描电子显微镜 (SEM) 和透射电子显微镜 (TEM) 进行结构和形态分析。该过程包括最初的 Ta2O5 电脱氧过程、随后在形成的 Ta 粒子上电沉积 Al3+ 以及原位合金化过程。创新性地使用具有新型分层多孔结构的 Ta2O5 阴极可以控制阴极颗粒形态的变化，并促进纳米级钽颗粒的快速生成。然后将电解液中的 Al3+ 电沉积到这些颗粒上，引发原位合金化反应。这是一个放热过程，有利于铝原子向钽中扩散，并降低界面能，促进球形 Al3Ta 颗粒的形成。这种粉末是 AM 技术所需要的。现在，这些发现可为建立电化学路线，以短时间制备其他高温合金粉末提供指导。
{"title":"One-step synthesis of spherical Al3Ta alloy powder by electrolyzing solid Ta2O5 in molten fluorides","authors":"Yapeng Kong, Longdi Ma, Heng Zhang, Xiwen Chen, Xuemin Liang, Liqiang Wang, Yangyang Fan, Yuran Chen","doi":"10.1016/j.electacta.2024.145354","DOIUrl":"10.1016/j.electacta.2024.145354","url":null,"abstract":"<div><div>Aluminum-tantalum powders are emerging as new raw materials for additive manufacturing (AM) technologies, but their preparation in bulk quantities and in powder form via conventional metallurgical methods is challenging. In this study, we report a one-step synthesis of spherical Al<sub>3</sub>Ta powder by direct electrolyzing solid Ta<sub>2</sub>O<sub>5</sub> cathode (<em>vs</em>. a graphite anode) in molten Na<sub>3</sub>AlF<sub>6</sub>-K<sub>3</sub>AlF<sub>6</sub>-AlF<sub>3</sub>-LiF-Al<sub>2</sub>O<sub>3</sub>. Cyclic voltammetry and constant potential electrolysis techniques were employed to characterize the electrochemical reaction process, along with X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for the structural and morphological analyses. The process involves an initial Ta<sub>2</sub>O<sub>5</sub> electro-deoxygenation process, the subsequent electrodeposition of Al<sup>3+</sup> on the formed Ta particles and an in-situ alloying process. The innovative use of Ta<sub>2</sub>O<sub>5</sub> cathodes with a novel hierarchical porous structure allows for a controlled transformation of cathode particle morphology and facilitates the rapid generation of nanoscale tantalum particles. Al<sup>3+</sup> from the electrolyte is then electrodeposited onto these particles, initiating an in-situ alloying reaction. This is an exothermic process that facilitates the diffusion of aluminum atoms into tantalum, and reduces the interfacial energy promoting the formation of spherical Al<sub>3</sub>Ta particles. Such powders are in demand for AM techniques. The findings may now guide the way to establishing the electrochemical route for the short-process preparation of other high-temperature alloy powders.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"510 ","pages":"Article 145354"},"PeriodicalIF":5.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601800","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}
Pub Date : 2024-11-09DOI: 10.1016/j.electacta.2024.145341
Shulin Li , Qiaoquan Lin , Han Yan , Qiaodong Li , Yu Yang , Xinlin Yan , Zhenyu Wang , Chuang Yu , Long Zhang
Cl-rich Li-argyrodites are one type of sulfide solid electrolytes (SSEs) with a high ionic conductivity and suitable mechanical properties for practical application. However, their tolerance against moisture in air and compatibility with metallic Li need further improvements. Here, we demonstrate that Nb-O dual-doping can be a good strategy for advanced Cl-rich Li-argyrodite SSEs, prepared by high energy ball milling and annealing method. Our results show that the Nb-O co-doping enhances the interface compatibility towards metallic Li and improves the moisture resistance, while maintains a fast ion transport. The Nb-O incorporation improves the Young's modulus and mitigates the side reaction of Li-argyrodite with Li. The doping-optimized sample demonstrates a high critical current density of 2.28 mA cm−2 and a long-term Li plating/stripping stability under a relatively high current density (1 mA cm−2) for nearly 3000 cycles. Notably, the corresponding all-solid-state lithium batteries (ASSLBs), using a Li metal electrode, can maintain a superior cycling stability for over 1000 cycles at 1 C.
富含锂离子的硫化物固态电解质（SSE）具有很高的离子电导率和适合实际应用的机械性能。然而，它们对空气中湿气的耐受性以及与金属锂的兼容性还需要进一步改进。在此，我们证明了 Nb-O 双掺杂是一种通过高能球磨和退火法制备富含 Cli-argyrodite 的先进锂离子固态电解质的良好策略。我们的研究结果表明，Nb-O 共掺杂增强了与金属锂的界面相容性，提高了耐湿性，同时保持了离子的快速传输。Nb-O 的掺入提高了杨氏模量，并减轻了锂阳起石与锂的副反应。经过掺杂优化的样品临界电流密度高达 2.28 mA cm-2，在相对较高的电流密度（1 mA cm-2）下，锂镀层/剥离具有近 3000 次循环的长期稳定性。值得注意的是，使用锂金属电极的相应全固态锂电池（ASSLBs）可在 1 C 下保持超过 1000 次循环的卓越稳定性。
{"title":"Enhanced air stability and interface compatibility in Nb-O-doped Cl-rich Li-argyrodites for all-solid-state Li metal batteries","authors":"Shulin Li , Qiaoquan Lin , Han Yan , Qiaodong Li , Yu Yang , Xinlin Yan , Zhenyu Wang , Chuang Yu , Long Zhang","doi":"10.1016/j.electacta.2024.145341","DOIUrl":"10.1016/j.electacta.2024.145341","url":null,"abstract":"<div><div>Cl-rich Li-argyrodites are one type of sulfide solid electrolytes (SSEs) with a high ionic conductivity and suitable mechanical properties for practical application. However, their tolerance against moisture in air and compatibility with metallic Li need further improvements. Here, we demonstrate that Nb-O dual-doping can be a good strategy for advanced Cl-rich Li-argyrodite SSEs, prepared by high energy ball milling and annealing method. Our results show that the Nb-O co-doping enhances the interface compatibility towards metallic Li and improves the moisture resistance, while maintains a fast ion transport. The Nb-O incorporation improves the Young's modulus and mitigates the side reaction of Li-argyrodite with Li. The doping-optimized sample demonstrates a high critical current density of 2.28 mA cm<sup>−2</sup> and a long-term Li plating/stripping stability under a relatively high current density (1 mA cm<sup>−2</sup>) for nearly 3000 cycles. Notably, the corresponding all-solid-state lithium batteries (ASSLBs), using a Li metal electrode, can maintain a superior cycling stability for over 1000 cycles at 1 C.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"509 ","pages":"Article 145341"},"PeriodicalIF":5.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596628","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}
This work reports the synthesis of copper- and cobalt-based coupled and mixed metal oxides (CuO-Co3O4 and CuCo2O4, respectively) utilizing a simple hydrothermal and calcination approach. CuO-Co3O4, CuCo2O4, and the control samples were characterized by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray, and X-ray photoelectron spectroscopy. TEM and FE-SEM analyses of CuO-Co3O4 reveal the presence of two distinct morphologies: rod- and sphere-shaped particles (CuO and Co3O4, respectively). Further, CuO-Co3O4 was efficiently utilized as an electrocatalyst for the selective oxidation of hydrazine (Hyz). CuO-Co3O4 shows a high redox response compared to CuO, Co3O4, CuCo2O4, and the physical mixture of CuO and Co3O4 (CuO/Co3O4). This enhanced performance is attributed to the synergistic interaction between the metal ions caused by their close proximity and the increased exposure of surface active sites. CuO-Co3O4 shows a broad linear range (1–3500 µM), a low detection limit (0.29 µM), and high sensitivity (0.5756 µA µM-1 cm-2) for the Hyz determination. Kinetic parameters, for instance the diffusion coefficient and catalytic rate constant for Hyz oxidation were obtained using chronoamperometry. Additionally, CuO-Co3O4 was effectively utilized to analyze Hyz in real samples with acceptable recovery rates.
{"title":"A comparative study on the electrocatalytic efficiency of coupled (CuO-Co3O4) vs. mixed (CuCo2O4) metal oxides: Probed by hydrazine oxidation and sensitive determination","authors":"Smita Singh, Varsha Singh, Vikram Rathour, Vellaichamy Ganesan","doi":"10.1016/j.electacta.2024.145337","DOIUrl":"10.1016/j.electacta.2024.145337","url":null,"abstract":"<div><div>This work reports the synthesis of copper- and cobalt-based coupled and mixed metal oxides (CuO-Co<sub>3</sub>O<sub>4</sub> and CuCo<sub>2</sub>O<sub>4</sub>, respectively) utilizing a simple hydrothermal and calcination approach. CuO-Co<sub>3</sub>O<sub>4</sub>, CuCo<sub>2</sub>O<sub>4</sub>, and the control samples were characterized by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray, and X-ray photoelectron spectroscopy. TEM and FE-SEM analyses of CuO-Co<sub>3</sub>O<sub>4</sub> reveal the presence of two distinct morphologies: rod- and sphere-shaped particles (CuO and Co<sub>3</sub>O<sub>4</sub>, respectively). Further, CuO-Co<sub>3</sub>O<sub>4</sub> was efficiently utilized as an electrocatalyst for the selective oxidation of hydrazine (Hyz). CuO-Co<sub>3</sub>O<sub>4</sub> shows a high redox response compared to CuO, Co<sub>3</sub>O<sub>4</sub>, CuCo<sub>2</sub>O<sub>4</sub>, and the physical mixture of CuO and Co<sub>3</sub>O<sub>4</sub> (CuO/Co<sub>3</sub>O<sub>4</sub>). This enhanced performance is attributed to the synergistic interaction between the metal ions caused by their close proximity and the increased exposure of surface active sites. CuO-Co<sub>3</sub>O<sub>4</sub> shows a broad linear range (1–3500 µM), a low detection limit (0.29 µM), and high sensitivity (0.5756 µA µM<sup>-1</sup> cm<sup>-2</sup>) for the Hyz determination. Kinetic parameters, for instance the diffusion coefficient and catalytic rate constant for Hyz oxidation were obtained using chronoamperometry. Additionally, CuO-Co<sub>3</sub>O<sub>4</sub> was effectively utilized to analyze Hyz in real samples with acceptable recovery rates.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"510 ","pages":"Article 145337"},"PeriodicalIF":5.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596624","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}
Pub Date : 2024-11-09DOI: 10.1016/j.electacta.2024.145330
Zhengqing Pei , Jiawei Wang , Haifeng Wang , Kexin Zheng , Qian Wang , Jiexin Zhou , Dehua Ma , Ju Lu , Fanghai Lu
The study investigated the evolution of LNMO (LiNi0.5Mn1.5O4) morphology and surface orientation as a function of increasing temperature. The results show that at an initial calcination temperature of 750 °C, LNMO exhibits spherical polyhedral with (111), (110), and (100) facets and relatively small particle sizes. In response to increasing temperatures, the particle size increases, the number of crystal facets decreases, and the material ultimately transitions to a typical spinel structure. Notably, the LNMO material calcined at 750 °C demonstrates a high lithium-ion migration rate, retaining 81.24% of its capacity after 500 cycles at a 2 C rate. This exceptional performance is attributed to the exposure of multiple crystal facets, suitable particle size, and the presence of Mn³⁺, which collectively stabilize the crystal structure and provide suitable pathways for Li⁺ transport.
{"title":"Morphological evolution and surface orientation effects of nickel manganese oxide in the preparation of LNMO cathode material","authors":"Zhengqing Pei , Jiawei Wang , Haifeng Wang , Kexin Zheng , Qian Wang , Jiexin Zhou , Dehua Ma , Ju Lu , Fanghai Lu","doi":"10.1016/j.electacta.2024.145330","DOIUrl":"10.1016/j.electacta.2024.145330","url":null,"abstract":"<div><div>The study investigated the evolution of LNMO (LiNi0.5Mn1.5O4) morphology and surface orientation as a function of increasing temperature. The results show that at an initial calcination temperature of 750 °C, LNMO exhibits spherical polyhedral with (111), (110), and (100) facets and relatively small particle sizes. In response to increasing temperatures, the particle size increases, the number of crystal facets decreases, and the material ultimately transitions to a typical spinel structure. Notably, the LNMO material calcined at 750 °C demonstrates a high lithium-ion migration rate, retaining 81.24% of its capacity after 500 cycles at a 2 C rate. This exceptional performance is attributed to the exposure of multiple crystal facets, suitable particle size, and the presence of Mn³⁺, which collectively stabilize the crystal structure and provide suitable pathways for Li⁺ transport.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"509 ","pages":"Article 145330"},"PeriodicalIF":5.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596713","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}
Pub Date : 2024-11-09DOI: 10.1016/j.electacta.2024.145343
Priyadharshini T , M. Lakshmi Narayana , Murugasenapathi N․K․ , Tamilarasan Palanisamy , A.V. Ravindra
Herein, we report the microwave hydrothermal synthesis of highly porous and conductive 2D Co-catecholate MOFs (Co-CATs) in the absence (Co-CAT-WO) and presence (Co-CAT-W) of N-methyl-2-pyrrolidone (NMP) polar solvent, and the study of these Co-CATs as electrocatalysts for oxygen evolution reaction (OER). The OER performance of Co-CAT-WO and Co-CAT-W is compared. The as-synthesized Co-CATs exhibit a 2D layered hexagonal structure. The electrical conductivity of Co-CAT-WO and Co-CAT-W is 6.9 and 5.8 S/m, respectively. The good conductivity and porous structure can initiate charge transport to achieve better OER performance under the 4e--transfer process. The as-prepared Co-CAT-WO and Co-CAT-W, respectively, show an overpotential of 455 and 424 mV at 10 mA/cm2 after performing the durability and chronoamperometry experiments for 13 h in 1 M KOH. From the electrochemical studies, it is apparent that the Co-CAT-W exhibits better OER performance with low overpotential, high current density, and excellent stability over extended cycling. Moreover, the lower HOMO-LUMO gap for Co-CAT-W than that of the Co-CAT-WO endorses its better electrocatalytic activity. The post-OER results show that the Co-CAT-W electrocatalyst acts as a "precatalyst" rather than the original catalyst, and it undergoes electrochemical transformation to metal hydroxide and metal oxyhydroxide after the OER studies, promoting the OER kinetics. The findings of this work offer valuable insights into the synthetic strategies for developing 2D conducting metal-catecholate MOF catalysts for efficient and sustainable OER processes, which is crucial in water splitting for sustainable energy production.
{"title":"Tailoring of electrocatalytic oxygen evolution reaction performance of 2D conductive Co-catecholate metal-organic frameworks","authors":"Priyadharshini T , M. Lakshmi Narayana , Murugasenapathi N․K․ , Tamilarasan Palanisamy , A.V. Ravindra","doi":"10.1016/j.electacta.2024.145343","DOIUrl":"10.1016/j.electacta.2024.145343","url":null,"abstract":"<div><div>Herein, we report the microwave hydrothermal synthesis of highly porous and conductive 2D Co-catecholate MOFs (Co-CATs) in the absence (Co-CAT-WO) and presence (Co-CAT-W) of N-methyl-2-pyrrolidone (NMP) polar solvent, and the study of these Co-CATs as electrocatalysts for oxygen evolution reaction (OER). The OER performance of Co-CAT-WO and Co-CAT-W is compared. The as-synthesized Co-CATs exhibit a 2D layered hexagonal structure. The electrical conductivity of Co-CAT-WO and Co-CAT-W is 6.9 and 5.8 S/m, respectively. The good conductivity and porous structure can initiate charge transport to achieve better OER performance under the 4e<sup>-</sup>-transfer process. The as-prepared Co-CAT-WO and Co-CAT-W, respectively, show an overpotential of 455 and 424 mV at 10 mA/cm<sup>2</sup> after performing the durability and chronoamperometry experiments for 13 h in 1 M KOH. From the electrochemical studies, it is apparent that the Co-CAT-W exhibits better OER performance with low overpotential, high current density, and excellent stability over extended cycling. Moreover, the lower HOMO-LUMO gap for Co-CAT-W than that of the Co-CAT-WO endorses its better electrocatalytic activity. The post-OER results show that the Co-CAT-W electrocatalyst acts as a \"precatalyst\" rather than the original catalyst, and it undergoes electrochemical transformation to metal hydroxide and metal oxyhydroxide after the OER studies, promoting the OER kinetics. The findings of this work offer valuable insights into the synthetic strategies for developing 2D conducting metal-catecholate MOF catalysts for efficient and sustainable OER processes, which is crucial in water splitting for sustainable energy production.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"509 ","pages":"Article 145343"},"PeriodicalIF":5.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596626","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}
Pub Date : 2024-11-09DOI: 10.1016/j.electacta.2024.145339
Ehtisham Umar , M. Waqas Iqbal , Fozia Shaheen , Hameed Ullah , Rizwan Wahab
Transition metal oxides are promising for hydrogen evolution reaction (HER) and hybrid energy storage due to their excellent redox properties, inherent electrochemical activity, and abundant electroactive sites. A significant challenge limiting their broader application is their intrinsic low electrical conductivity and reduced electrochemical stability. For hybrid energy storage devices and HER, a highly electrochemical active material is designed from 2D graphitic carbon nitride nanosheet (g-C3N4) networks anchored with strontium tungstate nanospheres (SrWO4/g-C3N4). The excellent performance observed can be attributed to several factors: multiple electro-active sites, well-defined electronic structures, and interaction between SrWO4 nanosphere on the surface of g-C3N4 nanosheets surface. The supercapattery device exhibited superior energy density (65.4 W h/kg) and power density (1240.5 W/kg) in comparison. In addition, the theoretical technique was utilized to provide a detailed analysis of the experimental findings. In addition, the SrWO4/g-C3N4 material demonstrates a low overpotential of 129 mV at -10 mA/cm2, along with Tafel slope values of 67 mV/dec for the HER, and it exhibits excellent cyclic stability. This study presents an advanced method for designing SrWO4/g-C3N4-based supercapacitors and HER platforms with nanoscale structures and optimized interface arrangements.
{"title":"Faradically dominant pseudocapacitive graphitic carbon nitride nanosheets decorated with strontium tungstate nanospheres for supercapattery device and hydrogen evaluation reaction","authors":"Ehtisham Umar , M. Waqas Iqbal , Fozia Shaheen , Hameed Ullah , Rizwan Wahab","doi":"10.1016/j.electacta.2024.145339","DOIUrl":"10.1016/j.electacta.2024.145339","url":null,"abstract":"<div><div>Transition metal oxides are promising for hydrogen evolution reaction (HER) and hybrid energy storage due to their excellent redox properties, inherent electrochemical activity, and abundant electroactive sites. A significant challenge limiting their broader application is their intrinsic low electrical conductivity and reduced electrochemical stability. For hybrid energy storage devices and HER, a highly electrochemical active material is designed from 2D graphitic carbon nitride nanosheet (g-C<sub>3</sub>N<sub>4</sub>) networks anchored with strontium tungstate nanospheres (SrWO<sub>4</sub>/g-C<sub>3</sub>N<sub>4</sub>). The excellent performance observed can be attributed to several factors: multiple electro-active sites, well-defined electronic structures, and interaction between SrWO<sub>4</sub> nanosphere on the surface of g-C<sub>3</sub>N<sub>4</sub> nanosheets surface. The supercapattery device exhibited superior energy density (65.4 W h/kg) and power density (1240.5 W/kg) in comparison. In addition, the theoretical technique was utilized to provide a detailed analysis of the experimental findings. In addition, the SrWO<sub>4</sub>/g-C<sub>3</sub>N<sub>4</sub> material demonstrates a low overpotential of 129 mV at -10 mA/cm<sup>2</sup>, along with Tafel slope values of 67 mV/dec for the HER, and it exhibits excellent cyclic stability. This study presents an advanced method for designing SrWO<sub>4</sub>/g-C<sub>3</sub>N<sub>4</sub>-based supercapacitors and HER platforms with nanoscale structures and optimized interface arrangements.</div></div>","PeriodicalId":305,"journal":{"name":"Electrochimica Acta","volume":"510 ","pages":"Article 145339"},"PeriodicalIF":5.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596625","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}
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