Pub Date : 2024-10-28DOI: 10.1016/j.jelechem.2024.118753
Ling Guo , Liyun Cao , Jianfeng Huang , Jiayin Li , Yong Zhao , Yijun Liu , Xing Wang , Yishou Wang
Mesocrystalline materials are reported to show great advantages in improving electrochemical performance. However, there are no reports about mesocrystalline Sb2O4 anode, and the structure advantage in reaction kinetics is unclear. In this work, we have prepared a mesocrystalline Sb2O4 structure (M−Sb2O4) in a facile hydrothermal process and further explored the structure effect on reaction kinetics. The exploration results show that the micro-flower mesocrystalline M−Sb2O4 consists of oriented nanowires with (110) crystal faces showing large surface area and high porosity. This structure can increase the contact area between electrode and electrolyte, provide fast Na+ transfer channels, and shorten the charge transport path, exhibiting excellent alloying reaction kinetics. The excellent reaction kinetics improves rate performance with a capacity of 432 mA h g-1 at 5 A g-1. Furthermore, it exhibits a high power density of 1700 W kg−1 in the full cell. Compared to the other reported various structured Sb-based anodes, M−Sb2O4 exhibits a great performance advantage. This work demonstrates that the mesocrystalline effect can effectively enhance alloying reaction kinetics, providing a new strategy for performance optimization of other alloy-based anodes.
据报道，介晶材料在提高电化学性能方面具有很大优势。然而，目前还没有关于介晶 Sb2O4 阳极的报道，其在反应动力学中的结构优势也不明确。在这项工作中，我们采用简便的水热法制备了介晶 Sb2O4 结构（M-Sb2O4），并进一步探讨了该结构对反应动力学的影响。研究结果表明，微花介晶 M-Sb2O4 由取向纳米线组成，晶面为（110），具有大表面积和高孔隙率。这种结构可以增加电极与电解液的接触面积，提供快速的 Na+ 传输通道，缩短电荷传输路径，表现出优异的合金化反应动力学。优异的反应动力学提高了速率性能，在 5 A g-1 的条件下，容量可达 432 mA h g-1。此外，它在全电池中还表现出 1700 W kg-1 的高功率密度。与其他已报道的各种结构的锑基阳极相比，M-Sb2O4 具有极大的性能优势。这项研究表明，介晶效应能有效提高合金化反应动力学，为其他合金基阳极的性能优化提供了一种新策略。
{"title":"Mesocrystalline effect boosts the alloying reaction kinetics of Sb2O4 anode in half/full sodium-ion batteries","authors":"Ling Guo , Liyun Cao , Jianfeng Huang , Jiayin Li , Yong Zhao , Yijun Liu , Xing Wang , Yishou Wang","doi":"10.1016/j.jelechem.2024.118753","DOIUrl":"10.1016/j.jelechem.2024.118753","url":null,"abstract":"<div><div>Mesocrystalline materials are reported to show great advantages in improving electrochemical performance. However, there are no reports about mesocrystalline Sb<sub>2</sub>O<sub>4</sub> anode, and the structure advantage in reaction kinetics is unclear. In this work, we have prepared a mesocrystalline Sb<sub>2</sub>O<sub>4</sub> structure (M−Sb<sub>2</sub>O<sub>4</sub>) in a facile hydrothermal process and further explored the structure effect on reaction kinetics. The exploration results show that the micro-flower mesocrystalline M−Sb<sub>2</sub>O<sub>4</sub> consists of oriented nanowires with (110) crystal faces showing large surface area and high porosity. This structure can increase the contact area between electrode and electrolyte, provide fast Na<sup>+</sup> transfer channels, and shorten the charge transport path, exhibiting excellent alloying reaction kinetics. The excellent reaction kinetics improves rate performance with a capacity of 432 mA h g<sup>-1</sup> at 5 A g<sup>-1</sup>. Furthermore, it exhibits a high power density of 1700 W kg<sup>−1</sup> in the full cell. Compared to the other reported various structured Sb-based anodes, M−Sb<sub>2</sub>O<sub>4</sub> exhibits a great performance advantage. This work demonstrates that the mesocrystalline effect can effectively enhance alloying reaction kinetics, providing a new strategy for performance optimization of other alloy-based anodes.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118753"},"PeriodicalIF":4.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.jelechem.2024.118751
Qin Li , Xingqiang Zhou , Haowei Hu , Kun Hu , Hui Liu , Xiaolong Fang
A novel dendritic nanostructure NiSe has been synthesized for electrocatalytic hydrogen evolution reaction (HER) through a hydrothermal method. The micromorphology and microstructure characterizations show that the branches of the dendritic NiSe are epitaxially grown on the trunk, and individual nickel selenide dendrites have three-dimensional structures with four branches in short axes. The nanostructures of each branch are paralleled to each other in the same plane, and are perpendicular to the trunk with the same crystal orientation. The dendritic NiSe catalyst demonstrates highly efficient HER activity with a low overpotential of 191 mV and a small Tafel slope of 47 mV dec−1 in acidic solutions. The remarkable enhancement of the dendritic NiSe in the HER performance can be attributed to its dense dendritic nano-structure, and high specific surface area, which provide effective diffusion channels and much more catalytic sites towards the HER. This achievement provides a new method for producing cheap and efficient dendritic nanostructures catalysts for water splitting.
通过水热法合成了用于电催化氢进化反应（HER）的新型树枝状纳米结构硒化镍。微观形貌和微观结构表征表明，树枝状硒化镍的分支是在主干上外延生长的，单个硒化镍树枝状物具有三维结构，短轴上有四个分支。每个树枝的纳米结构在同一平面内相互平行，并以相同的晶体取向垂直于主干。树枝状 NiSe 催化剂在酸性溶液中具有 191 mV 的低过电位和 47 mV dec-1 的小 Tafel 斜坡，表现出高效的 HER 活性。树枝状 NiSe 的 HER 性能之所以能显著提高，是因为其致密的树枝状纳米结构和高比表面积为 HER 提供了有效的扩散通道和更多的催化位点。这一成果为生产廉价高效的树枝状纳米结构催化剂提供了一种新方法。
{"title":"One-step synthesis of dendritic nanostructured single crystal NiSe electrocatalyst for hydrogen evolution reaction","authors":"Qin Li , Xingqiang Zhou , Haowei Hu , Kun Hu , Hui Liu , Xiaolong Fang","doi":"10.1016/j.jelechem.2024.118751","DOIUrl":"10.1016/j.jelechem.2024.118751","url":null,"abstract":"<div><div>A novel dendritic nanostructure NiSe has been synthesized for electrocatalytic hydrogen evolution reaction (HER) through a hydrothermal method. The micromorphology and microstructure characterizations show that the branches of the dendritic NiSe are epitaxially grown on the trunk, and individual nickel selenide dendrites have three-dimensional structures with four branches in short axes. The nanostructures of each branch are paralleled to each other in the same plane, and are perpendicular to the trunk with the same crystal orientation. The dendritic NiSe catalyst demonstrates highly efficient HER activity with a low overpotential of 191 mV and a small Tafel slope of 47 mV dec<sup>−1</sup> in acidic solutions. The remarkable enhancement of the dendritic NiSe in the HER performance can be attributed to its dense dendritic nano-structure, and high specific surface area, which provide effective diffusion channels and much more catalytic sites towards the HER. This achievement provides a new method for producing cheap and efficient dendritic nanostructures catalysts for water splitting.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118751"},"PeriodicalIF":4.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.jelechem.2024.118741
Ao Wang , Zhixue Tian , Xiaohan Li , Yujun Chai , Ning Wang
NASICON-type Na3V2(PO4)2F3 (NVPF) is a promising cathode material for Na-ion batteries due to its higher discharge capacity, appropriate voltage platform and output energy density. But its poor electronic conductivity should be increased to push its utilization. Here, the in-situ carbon and heteroatom B are introduced into to NVPF to improve the electrochemical performance. When citric acid is used as a carbon source, the free movement of electrons between V and the citric acid group is facilitated by the electrostatic force, causing a change in the valence state of V. It is a mixed valence of + 4 and + 3 for V in the product after annealing. The doping of B at O sites has no effect on ionic bond in solution and the crystal structure of the product. But, it decreases the formation energy, induces the charge redistribution and improves the conductivity. Excellent electrochemical performance is achieved with a B doping of 15 % to NVPF/C. Even after 1000 cycles, a capacity of 47.9 mAh g−1 is retained. The structure of NVPF/C-B is preserved during cycling, but compositional deviation at the electrode surface leads to some degradation. The relationship between the valence of V, doping B into the NVPF, and the degradation mechanism over repeated cycles provide a deep understanding of the complex interplay between metallic ions and carbon source, and the B-doping.
NASICON型Na3V2(PO4)2F3（NVPF）具有较高的放电容量、适当的电压平台和输出能量密度，是一种很有前途的镎离子电池正极材料。但其电子传导性较差，应提高其利用率。在此，我们在 NVPF 中引入了原位碳和杂原子 B，以改善其电化学性能。当使用柠檬酸作为碳源时，静电力会促进 V 与柠檬酸基团之间电子的自由移动，从而导致 V 的价态发生变化。在 O 位点掺入 B 对溶液中的离子键和产品的晶体结构没有影响。但是，它降低了形成能，诱导了电荷的重新分布，并提高了导电性。在 NVPF/C 中掺入 15% 的硼后，电化学性能极佳。即使经过 1000 次循环后，仍能保持 47.9 mAh g-1 的容量。在循环过程中，NVPF/C-B 的结构得以保留，但电极表面的成分偏差导致了一些降解。通过研究 V 的价态、在 NVPF 中掺杂 B 以及反复循环过程中的降解机制之间的关系，可以深入了解金属离子、碳源和 B 掺杂之间复杂的相互作用。
{"title":"Codoping of carbon and boron composition in Na3V2(PO4)2F3 affects its sodium storage properties","authors":"Ao Wang , Zhixue Tian , Xiaohan Li , Yujun Chai , Ning Wang","doi":"10.1016/j.jelechem.2024.118741","DOIUrl":"10.1016/j.jelechem.2024.118741","url":null,"abstract":"<div><div>NASICON-type Na<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>F<sub>3</sub> (NVPF) is a promising cathode material for Na-ion batteries due to its higher discharge capacity, appropriate voltage platform and output energy density. But its poor electronic conductivity should be increased to push its utilization. Here, the in-situ carbon and heteroatom B are introduced into to NVPF to improve the electrochemical performance. When citric acid is used as a carbon source, the free movement of electrons between V and the citric acid group is facilitated by the electrostatic force, causing a change in the valence state of V. It is a mixed valence of + 4 and + 3 for V in the product after annealing. The doping of B at O sites has no effect on ionic bond in solution and the crystal structure of the product. But, it decreases the formation energy, induces the charge redistribution and improves the conductivity. Excellent electrochemical performance is achieved with a B doping of 15 % to NVPF/C. Even after 1000 cycles, a capacity of 47.9 mAh g<sup>−1</sup> is retained. The structure of NVPF/C-B is preserved during cycling, but compositional deviation at the electrode surface leads to some degradation. The relationship between the valence of V, doping B into the NVPF, and the degradation mechanism over repeated cycles provide a deep understanding of the complex interplay between metallic ions and carbon source, and the B-doping.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118741"},"PeriodicalIF":4.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A direct and one-pot electrosynthesis method for the regioselective synthesis of bis methoxybiarenes via homocoupling of methoxyarenes has been studied in undivided cells in the transition-metal and oxidant-free conditions. The effect of various parameters, such as electrodes, electrolytes, and solvents has been studied and evaluated. To gain detailed mechanistic insight into the reaction, cyclic voltammetric (CV) studies of methoxyarenes were performed, and a radical pathway has been suggested. The reaction begins with an anodic oxidation of anisole to an anisyl cation radical followed by reaction with another anisole may form a new bisanisyl cation radical. The formed intermediate undergoes a hydrogen abstraction, followed by anodic oxidation gave bisanisyl cation and the bisanisole was obtained by abstraction of second hydrogen.
{"title":"Electrochemical synthesis of biaryls via CH/CH homocoupling of methoxyarenes","authors":"Babak Kaboudin , Sepideh Sadighi , Fahimeh Varmaghani , Leila Behrouzi","doi":"10.1016/j.jelechem.2024.118739","DOIUrl":"10.1016/j.jelechem.2024.118739","url":null,"abstract":"<div><div>A direct and one-pot electrosynthesis method for the regioselective synthesis of bis methoxybiarenes <em>via</em> homocoupling of methoxyarenes has been studied in undivided cells in the transition-metal and oxidant-free conditions. The effect of various parameters, such as electrodes, electrolytes, and solvents has been studied and evaluated. To gain detailed mechanistic insight into the reaction, cyclic voltammetric (CV) studies of methoxyarenes were performed, and a radical pathway has been suggested. The reaction begins with an anodic oxidation of anisole to an anisyl cation radical followed by reaction with another anisole may form a new bisanisyl cation radical. The formed intermediate undergoes a hydrogen abstraction, followed by anodic oxidation gave bisanisyl cation and the bisanisole was obtained by abstraction of second hydrogen.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118739"},"PeriodicalIF":4.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.jelechem.2024.118730
Ting Zhang , Jianguo Zhong , Wei Gao , Yuxin Wang
Transition metal-based materials are a type of catalyst that exhibits enhanced activity and stability during hydrogen production. However, suboptimal binding energy and nanoparticle aggregation during reactions restrict their practical use. Therefore, we report a simple and effective approach through a single-step phosphating reaction to adjust the d-band center of the catalyst, as well as protect the catalysts in the N, P doped carbon matrix from aggregation. Co-FeP@NPC exhibits enhanced HER performance with 95 mV and 159 mV at −10 mA cm−2 in both acid and alkaline electrolytes. Theoretical computations validate that the enhanced HER activity stems from the downshift of the d-band center, thus weakening adsorption toward the H* intermediate in hydrogen production. In addition, the N, P-doped carbon matrix serves to shield Co-FeP nanoparticles from aggregation, thereby enhancing the exposure of active sites during the reaction. This investigation unveils novel avenues for designing high-performance transition metal-based materials in catalysis.
过渡金属基材料是一种催化剂，在制氢过程中具有更高的活性和稳定性。然而，结合能不理想和纳米粒子在反应过程中的聚集限制了它们的实际应用。因此，我们报告了一种简单有效的方法，即通过一步磷化反应来调整催化剂的 d 波段中心，并保护掺杂 N、P 的碳基质中的催化剂免受聚集。Co-FeP@NPC 在-10 mA cm-2 的酸性和碱性电解质中分别表现出 95 mV 和 159 mV 的增强 HER 性能。理论计算验证了 HER 活性的增强源于 d 带中心的下移，从而削弱了对制氢过程中 H* 中间体的吸附。此外，掺杂 N、P 的碳基质还能防止 Co-FeP 纳米粒子聚集，从而提高反应过程中活性位点的暴露率。这项研究为设计高性能过渡金属催化材料开辟了新的途径。
{"title":"Facile synthesis of Co-FeP nanoparticles confined in N, P doped carbon matrix with modulated d-band center as an efficient HER catalyst","authors":"Ting Zhang , Jianguo Zhong , Wei Gao , Yuxin Wang","doi":"10.1016/j.jelechem.2024.118730","DOIUrl":"10.1016/j.jelechem.2024.118730","url":null,"abstract":"<div><div>Transition metal-based materials are a type of catalyst that exhibits enhanced activity and stability during hydrogen production. However, suboptimal binding energy and nanoparticle aggregation during reactions restrict their practical use. Therefore, we report a simple and effective approach through a single-step phosphating reaction to adjust the d-band center of the catalyst, as well as protect the catalysts in the N, P doped carbon matrix from aggregation. Co-FeP@NPC exhibits enhanced HER performance with 95 mV and 159 mV at −10 mA cm<sup>−2</sup> in both acid and alkaline electrolytes. Theoretical computations validate that the enhanced HER activity stems from the downshift of the d-band center, thus weakening adsorption toward the H* intermediate in hydrogen production. In addition, the N, P-doped carbon matrix serves to shield Co-FeP nanoparticles from aggregation, thereby enhancing the exposure of active sites during the reaction. This investigation unveils novel avenues for designing high-performance transition metal-based materials in catalysis.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118730"},"PeriodicalIF":4.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-26DOI: 10.1016/j.jelechem.2024.118748
Sivalingam Ramesh , Iqra Rabani , K. Senthilkumar , Yuvaraj Haldorai , Manickam Selvaraj , Young-Soo Seo , Joo-Hyung Kim , Heung Soo Kim
Metal organic framework-derived materials are promising electrodes for electrochemical supercapacitors due to their surface area, porosity, and excellent redox behaviors. In the present study the fabrication of ZnCo2S4 and ZnCo2S4@ZIF-67 composites synthesized by solid-state grinding and hydrothermal processing for supercapacitor utilization. Studies using XRD, XPS, FTIR, BET, FE-SEM, and HR-TEM are employed to validate the morphological, surface, and structural characteristics. Highly conductive ZnCo2S4 nanostructured materials are intercalated with MOF surfaces to enhance electron transport. The high number of active sites involved in the rapid electrochemical phase fluctuation using 1 M KOH electrolyte may be the cause of this. ZnCo2S4 and ZnCo2S4@ZIF-67 composites are used to create the working electrode, while a 1 M KOH electrolyte is used for the supercapacitor. By employing a three-electrode design, the created composite electrodes improve cyclic retention with specific capacitances of 245 and 447.14F/g at 1 A/g, respectively. Two electrode configurations are used to build ZnCo2S4@ZIF-67/1M KOH/SSC, which produced results of 151.42F/g at 1 A/g, 85.2 % capacitance retention at 7 A g−1 of 7000 cycles, and 18.93 Wh kg−1 energy density at 642.85 W kg−1 power density. Thus, the fabricated composite electrodes may find application in electrochemical symmetric supercapacitor via two electrode configuration systems.
{"title":"Enhancement of capacitance retention of ZnCo2S4@Metal organic framework composite electrodes by hydrothermal process","authors":"Sivalingam Ramesh , Iqra Rabani , K. Senthilkumar , Yuvaraj Haldorai , Manickam Selvaraj , Young-Soo Seo , Joo-Hyung Kim , Heung Soo Kim","doi":"10.1016/j.jelechem.2024.118748","DOIUrl":"10.1016/j.jelechem.2024.118748","url":null,"abstract":"<div><div>Metal organic framework-derived materials are promising electrodes for electrochemical supercapacitors due to their surface area, porosity, and excellent redox behaviors. In the present study the fabrication of ZnCo<sub>2</sub>S<sub>4</sub> and ZnCo<sub>2</sub>S<sub>4</sub>@ZIF-67 composites synthesized by solid-state grinding and hydrothermal processing for supercapacitor utilization. Studies using XRD, XPS, FTIR, BET, FE-SEM, and HR-TEM are employed to validate the morphological, surface, and structural characteristics. Highly conductive ZnCo<sub>2</sub>S<sub>4</sub> nanostructured materials are intercalated with MOF surfaces to enhance electron transport. The high number of active sites involved in the rapid electrochemical phase fluctuation using 1 M KOH electrolyte may be the cause of this. ZnCo<sub>2</sub>S<sub>4</sub> and ZnCo<sub>2</sub>S<sub>4</sub>@ZIF-67 composites are used to create the working electrode, while a 1 M KOH electrolyte is used for the supercapacitor. By employing a three-electrode design, the created composite electrodes improve cyclic retention with specific capacitances of 245 and 447.14F/g at 1 A/g, respectively. Two electrode configurations are used to build ZnCo<sub>2</sub>S<sub>4</sub>@ZIF-67/1M KOH/SSC, which produced results of 151.42F/g at 1 A/g, 85.2 % capacitance retention at 7 A g<sup>−1</sup> of 7000 cycles, and 18.93 Wh kg<sup>−1</sup> energy density at 642.85 W kg<sup>−1</sup> power density. Thus, the fabricated composite electrodes may find application in electrochemical symmetric supercapacitor via two electrode configuration systems.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118748"},"PeriodicalIF":4.1,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-26DOI: 10.1016/j.jelechem.2024.118749
Muhammad Adnan Younis , Ahmed I. Osman , Amjad Ali , Fazal Haq , Tariq Aziz , Mehwish Kiran , Iffat Ayesha Khan , Rizwan Wahab , Saira Manzoor
The electrochemical reduction of nitrogen to ammonia represents a greener alternative to the Haber-Bosch process, demanding a shift towards low-cost and high-efficiency electrocatalysts. Recent advances in research have demonstrated the potential of molybdenum carbide-based catalysts to have their unique electronic structure and physicochemical properties. This study introduces ultrathin iron-doped molybdenum carbide nanosheets (Fe-MoC) as a novel catalyst for ammonia electrosynthesis. Demonstrating a remarkable ammonia production rate of 16 µg h−1 mg−1 and a Faradaic efficiency (FE) of approximately 13 % at −0.2 V, our synthesized Fe-MoC nanosheets stand out for their superior catalytic activity and selectivity towards nitrogen activation. The indophenol technique was employed to identify the generation of NH3 in our experiments, followed by UV–vis spectrometry for quantitative analysis. Additionally, various characterization techniques, including XRD, Raman, and XPS, were used to analyze the material structure and surface properties. Through comprehensive characterization and electrochemical studies, we reveal the pivotal role of iron doping in enhancing the electrocatalytic performance for nitrogen reduction reaction (NRR), offering insights into the mechanistic pathways facilitated by Fe-MoC. The future development and perspective of Fe-MoC towards high performance are proposed.
{"title":"Molybdenum carbide nanosheets with iron doping as electrocatalysts for highly efficient ammonia electrosynthesis","authors":"Muhammad Adnan Younis , Ahmed I. Osman , Amjad Ali , Fazal Haq , Tariq Aziz , Mehwish Kiran , Iffat Ayesha Khan , Rizwan Wahab , Saira Manzoor","doi":"10.1016/j.jelechem.2024.118749","DOIUrl":"10.1016/j.jelechem.2024.118749","url":null,"abstract":"<div><div>The electrochemical reduction of nitrogen to ammonia represents a greener alternative to the Haber-Bosch process, demanding a shift towards low-cost and high-efficiency electrocatalysts. Recent advances in research have demonstrated the potential of molybdenum carbide-based catalysts to have their unique electronic structure and physicochemical properties. This study introduces ultrathin iron-doped molybdenum carbide nanosheets (Fe-MoC) as a novel catalyst for ammonia electrosynthesis. Demonstrating a remarkable ammonia production rate of 16 µg h<sup>−1</sup> mg<sup>−1</sup> and a Faradaic efficiency (FE) of approximately 13 % at −0.2 V, our synthesized Fe-MoC nanosheets stand out for their superior catalytic activity and selectivity towards nitrogen activation. The indophenol technique was employed to identify the generation of NH<sub>3</sub> in our experiments, followed by UV–vis spectrometry for quantitative analysis. Additionally, various characterization techniques, including XRD, Raman, and XPS, were used to analyze the material structure and surface properties. Through comprehensive characterization and electrochemical studies, we reveal the pivotal role of iron doping in enhancing the electrocatalytic performance for nitrogen reduction reaction (NRR), offering insights into the mechanistic pathways facilitated by Fe-MoC. The future development and perspective of Fe-MoC towards high performance are proposed.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"975 ","pages":"Article 118749"},"PeriodicalIF":4.1,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-26DOI: 10.1016/j.jelechem.2024.118743
Xinyi Liu , Ming Wu , Ke Gong , Dongxu Sun , Xu Wang , Jin Li , Jin Du , Jacob C. Huang
The effect of stress concentration on crack initiation and propagation during stress corrosion cracking of carbon steel in alternate wet and dry marine condition was studied by constant load tensile and microelectrochemical test. Results showed that the notch front does not crack but pitting occurs in the corrosion process under load-free condition. Under the loading condition, the anodic dissolution (AD) near the notch gradually intensified, and this effect become severer with increasing load. The local environment of the load-induced rapid AD and hydrogen evolution (HE) can lead to crack initiation, indicating that the joint action of AD and HE is the main SCC mechanism.
{"title":"Observations of stress corrosion cracking in pipeline steel in corrosive seawater environment including detailed observation of the crack initiation mechanism","authors":"Xinyi Liu , Ming Wu , Ke Gong , Dongxu Sun , Xu Wang , Jin Li , Jin Du , Jacob C. Huang","doi":"10.1016/j.jelechem.2024.118743","DOIUrl":"10.1016/j.jelechem.2024.118743","url":null,"abstract":"<div><div>The effect of stress concentration on crack initiation and propagation during stress corrosion cracking of carbon steel in alternate wet and dry marine condition was studied by constant load tensile and microelectrochemical test. Results showed that the notch front does not crack but pitting occurs in the corrosion process under load-free condition. Under the loading condition, the anodic dissolution (AD) near the notch gradually intensified, and this effect become severer with increasing load. The local environment of the load-induced rapid AD and hydrogen evolution (HE) can lead to crack initiation, indicating that the joint action of AD and HE is the main SCC mechanism.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"975 ","pages":"Article 118743"},"PeriodicalIF":4.1,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-26DOI: 10.1016/j.jelechem.2024.118734
An-ru Yan , Xiao-bo Wang , Ling Zhu , Xue-sheng Liu , Zhi-yong Wang
Economic viability and durability are pivotal challenges limiting the commercial application of proton exchange membrane fuel cells (PEMFC). The development of low Pt usage oxygen reduction reaction catalysts with high catalytic activity and durability is imperative. Carbon support corrosion, as well as Pt particles agglomeration and exfoliation are primary causes of commercial Pt/C catalyst degradation. Here, a composite materials formed by TiO2 containing oxygen vacancy (OV) and carbon nanotube (CNT) was used as a functional support to successfully load Pt nanoparticles (NPs). The oxygen vacancy facilitated interactions between TiO2(OV) and Pt, enhancing the anchoring of Pt NPs and suppressing particle growth. The Pt/TiO2(OV)-CNT demonstrates excellent performance with mass activity of 788 mA/mgPt @0.85 V, the half-wave potential increased 34 mV and the tafel slope decreased by 11.89 mVdec−1 compared to commercial Pt/C. The durability of Pt/TiO2(OV)-CNT nearly 3-fold that of commercial Pt/C with negligible decay of half-wave potential (0.9 %) and mass activity (16 %). Density functional theory calculations and X-ray photoelectron spectroscopy indicated that the charge transfer from TiO2(OV) to Pt facilitates the formation of strong metal-support interactions (SMSI), leading to a downward shift in the d-band center of Pt and a reduction in the binding strength to *OOH, thus lowering the activation energy of the rate-determining step which in turn promoting the activity of ORR. This study provides a reliable approach for designing catalysts with high activity and durability.
经济可行性和耐用性是限制质子交换膜燃料电池（PEMFC）商业应用的关键挑战。开发具有高催化活性和耐用性的低铂用量氧还原反应催化剂势在必行。碳支撑的腐蚀以及铂颗粒的团聚和剥落是导致商用 Pt/C 催化剂降解的主要原因。在这里，一种由含氧空位（OV）的二氧化钛和碳纳米管（CNT）形成的复合材料被用作成功负载铂纳米颗粒（NPs）的功能性支撑。氧空位促进了 TiO2（OV）和铂之间的相互作用，增强了铂纳米粒子的锚定，抑制了粒子的生长。与商用 Pt/C 相比，Pt/TiO2(OV)-CNT 表现出卓越的性能，在 0.85 V 时的质量活性为 788 mA/mgPt，半波电位提高了 34 mV，塔菲尔斜率降低了 11.89 mVdec-1。Pt/TiO2(OV)-CNT 的耐用性几乎是商用 Pt/C 的 3 倍，其半波电位衰减（0.9%）和质量活性衰减（16%）可以忽略不计。密度泛函理论计算和 X 射线光电子能谱表明，从 TiO2（OV）到铂的电荷转移促进了强金属-支撑相互作用（SMSI）的形成，导致铂的 d 带中心下移，与 *OOH 的结合强度降低，从而降低了速率决定步骤的活化能，进而提高了 ORR 的活性。这项研究为设计具有高活性和耐久性的催化剂提供了一种可靠的方法。
{"title":"Oxygen vacancy strategy enhancing the performance of TiO2/CNT supported ultrafine Pt catalyst for the oxygen reduction reaction","authors":"An-ru Yan , Xiao-bo Wang , Ling Zhu , Xue-sheng Liu , Zhi-yong Wang","doi":"10.1016/j.jelechem.2024.118734","DOIUrl":"10.1016/j.jelechem.2024.118734","url":null,"abstract":"<div><div>Economic viability and durability are pivotal challenges limiting the commercial application of proton exchange membrane fuel cells (PEMFC). The development of low Pt usage oxygen reduction reaction catalysts with high catalytic activity and durability is imperative. Carbon support corrosion, as well as Pt particles agglomeration and exfoliation are primary causes of commercial Pt/C catalyst degradation. Here, a composite materials formed by TiO<sub>2</sub> containing oxygen vacancy (O<sub>V</sub>) and carbon nanotube (CNT) was used as a functional support to successfully load Pt nanoparticles (NPs). The oxygen vacancy facilitated interactions between TiO<sub>2</sub>(O<sub>V</sub>) and Pt, enhancing the anchoring of Pt NPs and suppressing particle growth. The Pt/TiO<sub>2</sub>(O<sub>V</sub>)-CNT demonstrates excellent performance with mass activity of 788 mA/mg<sub>Pt</sub> @0.85 V, the half-wave potential increased 34 mV and the tafel slope decreased by 11.89 mVdec<sup>−1</sup> compared to commercial Pt/C. The durability of Pt/TiO<sub>2</sub>(O<sub>V</sub>)-CNT nearly 3-fold that of commercial Pt/C with negligible decay of half-wave potential (0.9 %) and mass activity (16 %). Density functional theory calculations and X-ray photoelectron spectroscopy indicated that the charge transfer from TiO<sub>2</sub>(O<sub>V</sub>) to Pt facilitates the formation of strong metal-support interactions (SMSI), leading to a downward shift in the d-band center of Pt and a reduction in the binding strength to *OOH, thus lowering the activation energy of the rate-determining step which in turn promoting the activity of ORR. This study provides a reliable approach for designing catalysts with high activity and durability.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"974 ","pages":"Article 118734"},"PeriodicalIF":4.1,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-26DOI: 10.1016/j.jelechem.2024.118742
Giorgia Rinaldi , Khadijeh Nekoueian , Jarkko Etula , Tomi Laurila
This study investigates how varying the thickness of tetrahedral amorphous carbon (ta-C) thin films and incorporating a titanium adhesion layer influences the structural and electrochemical properties of molecularly imprinted ta-C thin film-based sensing platforms, aiming to develop a molecularly imprinted ta-C electrochemical sensor for dopamine (DA) detection with physiologically relevant sensitivity. This electrochemical sensing platform was designed by integrating ta-C with molecularly imprinted polymers (MIPs). The process involved depositing a ta-C thin film onto boron-doped p-type silicon wafers through a filtered cathodic vacuum arc (FCVA) system. Subsequently, the ta-C sensing platforms were electrochemically coated with the MIP layer (DA-imprinted polypyrrole). We evaluated three configurations: (i) a 15 nm ta-C layer, (ii) a 7 nm ta-C layer with a 20 nm titanium adhesion layer, and (iii) a 15 nm ta-C layer with a 20 nm titanium adhesion layer. Comprehensive structural and electrochemical characterization was performed to understand how these modifications affect sensor performance. The optimized MIP/ta-C sensor demonstrated a sensitivity of 0.16 μA μM−1 cm−2 and a limit of detection (LOD) of 48.6 nM, suitable for detecting DA at physiological levels. Leveraging the synergistic effects of ta-C coatings and molecular imprinting, as well as its compatibility with common complementary metal–oxide–semiconductor (CMOS) processes underlines its potential for integration into microanalytical systems, paving the way for miniaturized and high-throughput sensing platforms.
{"title":"Development of smart molecularly imprinted tetrahedral amorphous carbon thin films for in vitro dopamine sensing","authors":"Giorgia Rinaldi , Khadijeh Nekoueian , Jarkko Etula , Tomi Laurila","doi":"10.1016/j.jelechem.2024.118742","DOIUrl":"10.1016/j.jelechem.2024.118742","url":null,"abstract":"<div><div>This study investigates how varying the thickness of tetrahedral amorphous carbon (ta-C) thin films and incorporating a titanium adhesion layer influences the structural and electrochemical properties of molecularly imprinted ta-C thin film-based sensing platforms, aiming to develop a molecularly imprinted ta-C electrochemical sensor for dopamine (DA) detection with physiologically relevant sensitivity. This electrochemical sensing platform was designed by integrating ta-C with molecularly imprinted polymers (MIPs). The process involved depositing a ta-C thin film onto boron-doped p-type silicon wafers through a filtered cathodic vacuum arc (FCVA) system. Subsequently, the ta-C sensing platforms were electrochemically coated with the MIP layer (DA-imprinted polypyrrole). We evaluated three configurations: (i) a 15 nm ta-C layer, (ii) a 7 nm ta-C layer with a 20 nm titanium adhesion layer, and (iii) a 15 nm ta-C layer with a 20 nm titanium adhesion layer. Comprehensive structural and electrochemical characterization was performed to understand how these modifications affect sensor performance. The optimized MIP/ta-C sensor demonstrated a sensitivity of 0.16 μA μM<sup>−1</sup> cm<sup>−2</sup> and a limit of detection (LOD) of 48.6 nM, suitable for detecting DA at physiological levels. Leveraging the synergistic effects of ta-C coatings and molecular imprinting, as well as its compatibility with common complementary metal–oxide–semiconductor (CMOS) processes underlines its potential for integration into microanalytical systems, paving the way for miniaturized and high-throughput sensing platforms.</div></div>","PeriodicalId":355,"journal":{"name":"Journal of Electroanalytical Chemistry","volume":"976 ","pages":"Article 118742"},"PeriodicalIF":4.1,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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