Joel Kingston Ramesh, Sasan Rostami, Jayaprakasan Rajesh, R. Margrate Bhackiyavathi Princess, Radhika Govindaraju, Jinho Kim, Rainer Adelung, Rajkumar Palanisamy, Mozaffar Abdollahifar
ZnMn2O4 (ZMO) has emerged as a promising material for energy storage applications due to its high theoretical capacity, low cost, and environmental friendliness. This review comprehensively explores the structure, synthesis methods, and performance of ZMO in various energy storage systems, including supercapacitors and batteries such as lithium-ion (LIBs), sodium-ion (SIBs) and zinc-ion (ZIBs) batteries, due to exceptional electrochemical properties. The influence of various synthesis techniques on the structural and morphological features of ZMO, which directly impact its electrochemical performance will be discussed. The review also delves into the charge storage mechanism of ZMO in supercapacitors, examining the effects of morphology, composites, and doping on its performance. Additionally, the use of ZMO as an anode material for LIBs and SIBs and its potential as a cathode material in ZIBs are discussed. The review also addresses key challenges and proposes strategies to enhance performance including incorporating conductive materials, synergizing with other materials, and doping. An outlook on the current challenges, future directions, and potential pathways for performance enhancement is also presented
{"title":"ZnMn2O4 Applications in Batteries and Supercapacitors: A Comprehensive Review","authors":"Joel Kingston Ramesh, Sasan Rostami, Jayaprakasan Rajesh, R. Margrate Bhackiyavathi Princess, Radhika Govindaraju, Jinho Kim, Rainer Adelung, Rajkumar Palanisamy, Mozaffar Abdollahifar","doi":"10.1039/d5ta00815h","DOIUrl":"https://doi.org/10.1039/d5ta00815h","url":null,"abstract":"ZnMn2O4 (ZMO) has emerged as a promising material for energy storage applications due to its high theoretical capacity, low cost, and environmental friendliness. This review comprehensively explores the structure, synthesis methods, and performance of ZMO in various energy storage systems, including supercapacitors and batteries such as lithium-ion (LIBs), sodium-ion (SIBs) and zinc-ion (ZIBs) batteries, due to exceptional electrochemical properties. The influence of various synthesis techniques on the structural and morphological features of ZMO, which directly impact its electrochemical performance will be discussed. The review also delves into the charge storage mechanism of ZMO in supercapacitors, examining the effects of morphology, composites, and doping on its performance. Additionally, the use of ZMO as an anode material for LIBs and SIBs and its potential as a cathode material in ZIBs are discussed. The review also addresses key challenges and proposes strategies to enhance performance including incorporating conductive materials, synergizing with other materials, and doping. An outlook on the current challenges, future directions, and potential pathways for performance enhancement is also presented","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"16 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bin Wang, Chao Zhu, Hai Lei, Hanyu Zhou, Wei Sun, Yue Yang, Peng Ge
Attracted by the economic and environmental value, the direct regeneration of spent Ni–Co–Mn oxides has captured plenty of attention. However, considering the low bonding energy of metal–oxygen, F-elements from binders and LiPF6 can be introduced into the bulk phase of regenerated samples, resulting in poor electrochemical properties. Herein, supported by CaO powders, regenerated cathodes were successfully obtained through the formation and removal of CaF2. By tailoring thermal sintering, the as-optimized sample exhibited a smooth surface and an intact morphology/lattice structure. More importantly, benefitting from the formation of oxygen vacancies, a rich oxygen-lattice surface/near-surface was established, exhibiting high stability. As a Li-storage cathode, the as-optimized samples delivered a capacity of 149.7 mA h g−1. The retention ratio remained at approximately 96.3% after 150 loops at 1.0 C. Even at 5.0 C, the capacity reached 134.1 mA h g−1, maintaining ∼84.7% retention after 300 cycles. Detailed kinetic behaviors analysis indicated an improved diffusion coefficient and reduced interfacial resistance, accompanied by a reduction in the voltage gap. Moreover, in situ resistance analysis revealed that stable charge-transfer resistance further alleviated internal stress variation. Thus, this study is expected to illustrate the regeneration process of spent Ni–Co–Mn oxides after the successful removal of F-impurities.
{"title":"Regeneration of spent NCM622: reconstructing the rich lattice oxygen surface for enhanced stability","authors":"Bin Wang, Chao Zhu, Hai Lei, Hanyu Zhou, Wei Sun, Yue Yang, Peng Ge","doi":"10.1039/d5ta00776c","DOIUrl":"https://doi.org/10.1039/d5ta00776c","url":null,"abstract":"Attracted by the economic and environmental value, the direct regeneration of spent Ni–Co–Mn oxides has captured plenty of attention. However, considering the low bonding energy of metal–oxygen, F-elements from binders and LiPF<small><sub>6</sub></small> can be introduced into the bulk phase of regenerated samples, resulting in poor electrochemical properties. Herein, supported by CaO powders, regenerated cathodes were successfully obtained through the formation and removal of CaF<small><sub>2</sub></small>. By tailoring thermal sintering, the as-optimized sample exhibited a smooth surface and an intact morphology/lattice structure. More importantly, benefitting from the formation of oxygen vacancies, a rich oxygen-lattice surface/near-surface was established, exhibiting high stability. As a Li-storage cathode, the as-optimized samples delivered a capacity of 149.7 mA h g<small><sup>−1</sup></small>. The retention ratio remained at approximately 96.3% after 150 loops at 1.0 C. Even at 5.0 C, the capacity reached 134.1 mA h g<small><sup>−1</sup></small>, maintaining ∼84.7% retention after 300 cycles. Detailed kinetic behaviors analysis indicated an improved diffusion coefficient and reduced interfacial resistance, accompanied by a reduction in the voltage gap. Moreover, <em>in situ</em> resistance analysis revealed that stable charge-transfer resistance further alleviated internal stress variation. Thus, this study is expected to illustrate the regeneration process of spent Ni–Co–Mn oxides after the successful removal of F-impurities.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"1156 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Single-atom electrocatalysts with Ni-Nx-C site usually possess an excellent activity for the CO2 reduction reaction (CO2RR). However, it still remains a challenge to synthesize them using unmodified nickel phthalocyanine (NiPc) with intrinsic Ni-N4-C moiety at room temperature. Here, NiPc molecules are controllably dispersed on graphene oxide (GO) in the form of single molecule, dimer, or aggregate through a simple hydrolysis of protonated NiPc in GO-contained aqueous phase. Systematic characterizations show the existence of π-π interaction, hydrogen bond and axial coordination between NiPc and GO in NiPc-GO composites. The electrochemical tests demonstrate that these NiPc-GO composites have high activity for electrocatalytic CO2RR to CO. After optimizing GO content in NiPc-GO, the CO Faraday efficiency of > 95% is achieved at work potential range from −0.8 to −1.1 VRHE, and it is up to 98.6% at −0.9 VRHE. Further experiments confirm that GO in NiPc-GO benefits for CO2 adsorption and formation of *COOH intermediate. The change of Ni2+/Ni3+ ratio with the GO amount in NiPc-GO composites reveals that the Ni(Ⅱ)/Ni(Ⅲ)/GO heterojunction structure should be the most conductive to the CO2RR process. This work provides an insight into the design and synthesis of single-atom Ni-N4-C electrocatalysts for CO2RR.
{"title":"Controllable Dispersion of Nickel Phthalocyanine Molecules on Graphene Oxide for Efficiently Electrocatalytic CO2 reduction","authors":"Jiaxin He, Yu Han, Xiao Xu, Miao Sun, Longtian Kang, Wenlie Lin, Jingjing Liu","doi":"10.1039/d5ta01623a","DOIUrl":"https://doi.org/10.1039/d5ta01623a","url":null,"abstract":"Single-atom electrocatalysts with Ni-Nx-C site usually possess an excellent activity for the CO<small><sub>2</sub></small> reduction reaction (CO<small><sub>2</sub></small>RR). However, it still remains a challenge to synthesize them using unmodified nickel phthalocyanine (NiPc) with intrinsic Ni-N<small><sub>4</sub></small>-C moiety at room temperature. Here, NiPc molecules are controllably dispersed on graphene oxide (GO) in the form of single molecule, dimer, or aggregate through a simple hydrolysis of protonated NiPc in GO-contained aqueous phase. Systematic characterizations show the existence of π-π interaction, hydrogen bond and axial coordination between NiPc and GO in NiPc-GO composites. The electrochemical tests demonstrate that these NiPc-GO composites have high activity for electrocatalytic CO<small><sub>2</sub></small>RR to CO. After optimizing GO content in NiPc-GO, the CO Faraday efficiency of > 95% is achieved at work potential range from −0.8 to −1.1 VRHE, and it is up to 98.6% at −0.9 VRHE. Further experiments confirm that GO in NiPc-GO benefits for CO<small><sub>2</sub></small> adsorption and formation of *COOH intermediate. The change of Ni<small><sup>2+</sup></small>/Ni<small><sup>3+ </sup></small>ratio with the GO amount in NiPc-GO composites reveals that the Ni(Ⅱ)/Ni(Ⅲ)/GO heterojunction structure should be the most conductive to the CO<small><sub>2</sub></small>RR process. This work provides an insight into the design and synthesis of single-atom Ni-N<small><sub>4</sub></small>-C electrocatalysts for CO<small><sub>2</sub></small>RR.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"107 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143766947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A crucial step in the large-scale fabrication of organic photovoltaic (OPV) cells is the coating of the functional layers, which directly influences the efficiency and stability of OPV cells. Among various coating techniques, Meniscus-guided coating (MGC) method has emerged as a promising approach, demonstrating unique advantages in achieving uniform and reproducible films while maintaining high material utilization efficiency. This review specifically focuses on the fluid flow dynamics and drying kinetics involved in the MGC process. We systematically analyse how coating parameters, such as coating speed, solution viscosity, and substrate surface energy, govern the final film morphology and device performance. Understanding these dynamics is essential for optimizing the MGC process and fabricating high-quality OPV cells with consistent performance. Besides, we summarize the recent progress in MGC for OPV cells and highlight the state-of-the-art results. Finally, we propose some forward-looking perspectives on the MGC method, with the aim of promoting the commercialization of OPV technology.
{"title":"Meniscus-Guided Coating for Organic Photovoltaic Cells","authors":"Wenye Xu, Yue Yu, Yong Cui, Jianhui Hou","doi":"10.1039/d5ta01491c","DOIUrl":"https://doi.org/10.1039/d5ta01491c","url":null,"abstract":"A crucial step in the large-scale fabrication of organic photovoltaic (OPV) cells is the coating of the functional layers, which directly influences the efficiency and stability of OPV cells. Among various coating techniques, Meniscus-guided coating (MGC) method has emerged as a promising approach, demonstrating unique advantages in achieving uniform and reproducible films while maintaining high material utilization efficiency. This review specifically focuses on the fluid flow dynamics and drying kinetics involved in the MGC process. We systematically analyse how coating parameters, such as coating speed, solution viscosity, and substrate surface energy, govern the final film morphology and device performance. Understanding these dynamics is essential for optimizing the MGC process and fabricating high-quality OPV cells with consistent performance. Besides, we summarize the recent progress in MGC for OPV cells and highlight the state-of-the-art results. Finally, we propose some forward-looking perspectives on the MGC method, with the aim of promoting the commercialization of OPV technology.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"58 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christian Heinekamp, Arkendu Roy, Stephanos Karafiludis, Sourabh Kumar, Ana Guilherme Buzanich, Tomasz Maciej Stawski, Aistė Miliūtė, Marcus Florian von der Au, Mike Ahrens, Thomas Braun, Franziska Emmerling
Extended hydrogen initiatives promote the urgency of research on water splitting technologies and therein oxygen evolution reaction catalysts being developed. A route to access a ZrF4 supported high-entropy fluoride catalyst using a facile sol-gel route is presented. The high-entropy character of the catalyst was confirmed by scanning transmission electron microscopy and energy dispersive X-ray spectroscopy (STEM-EDX) as well as inductively coupled plasma-mass spectrometry (ICP-MS). Additional investitions on the local structure were performed using extended X-ray absorption fine structure spectroscopy (EXAFS) and pair distribution function (PDF) analysis. The catalyst shows significant potential for oxygen evolution reaction (OER) in alkaline media with a current density of 100 mA cm-2 at approximately 1.60 V, thus outperforming benchmark materials such as IrO2, despite a significant reduction in electrochemical mass loading. A potential mechanism is suggested based on free energy calculation using DFT calulations.
氢能计划的扩展推动了水分离技术研究的紧迫性，其中氧进化反应催化剂的开发也迫在眉睫。本文介绍了一种利用简便的溶胶-凝胶法获得 ZrF4 支持的高熵氟化物催化剂的途径。该催化剂的高熵特性通过扫描透射电子显微镜和能量色散 X 射线光谱法（STEM-EDX）以及电感耦合等离子体质谱法（ICP-MS）得到了证实。此外，还利用扩展 X 射线吸收精细结构光谱（EXAFS）和对分布函数（PDF）分析对局部结构进行了研究。该催化剂在碱性介质中的氧进化反应（OER）中显示出巨大的潜力，在约 1.60 V 的电压下，电流密度为 100 mA cm-2，因此，尽管电化学质量负荷显著降低，但其性能优于 IrO2 等基准材料。利用 DFT 计算自由能，提出了一种潜在的机理。
{"title":"Zirconium Fluoride-Supported High-Entropy Fluoride: A Catalyst for Enhanced Oxygen Evolution Reaction","authors":"Christian Heinekamp, Arkendu Roy, Stephanos Karafiludis, Sourabh Kumar, Ana Guilherme Buzanich, Tomasz Maciej Stawski, Aistė Miliūtė, Marcus Florian von der Au, Mike Ahrens, Thomas Braun, Franziska Emmerling","doi":"10.1039/d4ta08664c","DOIUrl":"https://doi.org/10.1039/d4ta08664c","url":null,"abstract":"Extended hydrogen initiatives promote the urgency of research on water splitting technologies and therein oxygen evolution reaction catalysts being developed. A route to access a ZrF4 supported high-entropy fluoride catalyst using a facile sol-gel route is presented. The high-entropy character of the catalyst was confirmed by scanning transmission electron microscopy and energy dispersive X-ray spectroscopy (STEM-EDX) as well as inductively coupled plasma-mass spectrometry (ICP-MS). Additional investitions on the local structure were performed using extended X-ray absorption fine structure spectroscopy (EXAFS) and pair distribution function (PDF) analysis. The catalyst shows significant potential for oxygen evolution reaction (OER) in alkaline media with a current density of 100 mA cm-2 at approximately 1.60 V, thus outperforming benchmark materials such as IrO2, despite a significant reduction in electrochemical mass loading. A potential mechanism is suggested based on free energy calculation using DFT calulations.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"58 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As a unique type of intelligent material, liquid crystal elastomers (LCEs) have numerous valuable advantages and show significant potential for application in the design of flexible actuators. Nevertheless, attaining controllable and precise orientation of LCEs using easily operated methods continues to pose a considerable challenge. In this study, a synchronous differential orientation strategy based on dual dynamic covalent bonds (DCBs) was proposed to solve these problems. Through the integration of dynamic boronic ester bonds and dynamic siloxane bonds into the LCE network, bilayer LCE films that exhibit distinct orientation configurations can be easily fabricated. Meanwhile, the variation in the bond energy between these two chemical bonds provides the ability to control the orientation of each layer separately, resulting in LCE films with adjustable bending angles. Furthermore, the addition of azobenzene to the LCE composition enables the material to undergo reversible bending when illuminated with alternating ultraviolet and visible light, revealing the potential for various actuation capabilities in innovative materials. This approach not only dramatically enhances the self-healing, programming, and recycling of LCEs, but also paves the way for the development of advanced flexible actuators with complex deformation properties, holding substantial potential for applications in robotics, biomedicine, and intelligent devices.
{"title":"Synchronous differential orientation of liquid crystal elastomers based on dual dynamic covalent bonds","authors":"Zhentian Xu, Yangyang Zhu, Yun Ai, Zhongyi Yuan, Chunquan Li, Dan Zhou, Lie Chen","doi":"10.1039/d5ta00568j","DOIUrl":"https://doi.org/10.1039/d5ta00568j","url":null,"abstract":"As a unique type of intelligent material, liquid crystal elastomers (LCEs) have numerous valuable advantages and show significant potential for application in the design of flexible actuators. Nevertheless, attaining controllable and precise orientation of LCEs using easily operated methods continues to pose a considerable challenge. In this study, a synchronous differential orientation strategy based on dual dynamic covalent bonds (DCBs) was proposed to solve these problems. Through the integration of dynamic boronic ester bonds and dynamic siloxane bonds into the LCE network, bilayer LCE films that exhibit distinct orientation configurations can be easily fabricated. Meanwhile, the variation in the bond energy between these two chemical bonds provides the ability to control the orientation of each layer separately, resulting in LCE films with adjustable bending angles. Furthermore, the addition of azobenzene to the LCE composition enables the material to undergo reversible bending when illuminated with alternating ultraviolet and visible light, revealing the potential for various actuation capabilities in innovative materials. This approach not only dramatically enhances the self-healing, programming, and recycling of LCEs, but also paves the way for the development of advanced flexible actuators with complex deformation properties, holding substantial potential for applications in robotics, biomedicine, and intelligent devices.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"12 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qihang Wang, Jiqiong Liu, Huichao Lu, Liu Shuo, Liangyu Wang, Chenran Hao, Han Jing, Jun Yang, Yanna NuLi, Jiulin Wang
With the growing concern over increasing energy density, lithium-sulfur batteries have garnered significant interest from researchers. However, the volume expansion of the sulfur cathode, which leads to poor cycling stability at high loadings, poses a major challenge to their practical application. Traditional binders are highly susceptible to cracking and structural collapse as the coating thickness increases. Our study presents a dual-component composite binder (G2CEA) that harmoniously blends rigidity and flexibility, with each component serving a specific function. Guar gum (GG), the rigid component, envelops the SPAN interface and contributes to the formation of the CEI film, ensuring interface stability. Poly(2-Carboxyethyl acrylate) (PCEA), the flexible component, retains adhesion and ductility in the electrolyte, cushioning the volume changes of SPAN particles and maintaining the structural integrity of the electrode. This innovative design endows the G2CEA-based cathode with superior cycling stability (97.6% retention after 164 cycles at 0.1C) under high loadings (7.5 mg cm-²), offering a valuable perspective for the design of practical binders in the future.
{"title":"A Rigid-flexible Binder for Sulfurized Polyacrylonitrile Cathode for Rechargeable Lithium Battery","authors":"Qihang Wang, Jiqiong Liu, Huichao Lu, Liu Shuo, Liangyu Wang, Chenran Hao, Han Jing, Jun Yang, Yanna NuLi, Jiulin Wang","doi":"10.1039/d5ta01612f","DOIUrl":"https://doi.org/10.1039/d5ta01612f","url":null,"abstract":"With the growing concern over increasing energy density, lithium-sulfur batteries have garnered significant interest from researchers. However, the volume expansion of the sulfur cathode, which leads to poor cycling stability at high loadings, poses a major challenge to their practical application. Traditional binders are highly susceptible to cracking and structural collapse as the coating thickness increases. Our study presents a dual-component composite binder (G2CEA) that harmoniously blends rigidity and flexibility, with each component serving a specific function. Guar gum (GG), the rigid component, envelops the SPAN interface and contributes to the formation of the CEI film, ensuring interface stability. Poly(2-Carboxyethyl acrylate) (PCEA), the flexible component, retains adhesion and ductility in the electrolyte, cushioning the volume changes of SPAN particles and maintaining the structural integrity of the electrode. This innovative design endows the G2CEA-based cathode with superior cycling stability (97.6% retention after 164 cycles at 0.1C) under high loadings (7.5 mg cm-²), offering a valuable perspective for the design of practical binders in the future.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"30 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pengcheng Wang, Yang Yang, Hongda Shi, Jiahe Yang, Xingyan Chen, Xi Lin, Qianwang Chen, Mingzai Wu
Owing to its higher oxophilicity and similar hydrogen adsorption strength to Pt, Ru has been regarded as a promising alternative to overcome sluggish hydrogen oxidation reaction (HOR) kinetics in alkaline media. However, the strong oxophilicity of Ru also results in insufficient hydrogen adsorption sites on Ru catalysts and poor stability. Herein, a rationally designed Ru-based heterostructure catalyst with abundant Ru and MoC interfaces (Ru-MoC/C) was prepared. Ru-MoC/C exhibits great stability and excellent mass activity (1.74 mA μgPGM-1), which is approximately 4 and 3 times greater than that of Ru/C and Pt/C, respectively. And Ru-MoC/C displays a stable operation for 10000s at 0.1V in chronoamperometry test. Experimental results and theoretical simulations reveal that the electron transfer from Ru to MoC at heterostructure interfaces, derived from the differences in work functions, causes the d band center of Ru in Ru-MoC/C to move down, thus weakening the hydrogen binding as well as hydroxyl binding at Ru sites. While the strong oxophilic MoC could substitute for Ru as a hydroxyl adsorption sites, resulting in enhanced hydroxyl binding at the heterostructure interfaces. Consequently, these factors synergistically accelerate the HOR kinetics on Ru-MoC/C and promote the stability of Ru-MoC/C.
{"title":"Ru-MoC Heterostructure Electrocatalyst for Efficient and Stable Hydrogen Oxidation Reactions in Alkaline Media","authors":"Pengcheng Wang, Yang Yang, Hongda Shi, Jiahe Yang, Xingyan Chen, Xi Lin, Qianwang Chen, Mingzai Wu","doi":"10.1039/d5ta00941c","DOIUrl":"https://doi.org/10.1039/d5ta00941c","url":null,"abstract":"Owing to its higher oxophilicity and similar hydrogen adsorption strength to Pt, Ru has been regarded as a promising alternative to overcome sluggish hydrogen oxidation reaction (HOR) kinetics in alkaline media. However, the strong oxophilicity of Ru also results in insufficient hydrogen adsorption sites on Ru catalysts and poor stability. Herein, a rationally designed Ru-based heterostructure catalyst with abundant Ru and MoC interfaces (Ru-MoC/C) was prepared. Ru-MoC/C exhibits great stability and excellent mass activity (1.74 mA μgPGM-1), which is approximately 4 and 3 times greater than that of Ru/C and Pt/C, respectively. And Ru-MoC/C displays a stable operation for 10000s at 0.1V in chronoamperometry test. Experimental results and theoretical simulations reveal that the electron transfer from Ru to MoC at heterostructure interfaces, derived from the differences in work functions, causes the d band center of Ru in Ru-MoC/C to move down, thus weakening the hydrogen binding as well as hydroxyl binding at Ru sites. While the strong oxophilic MoC could substitute for Ru as a hydroxyl adsorption sites, resulting in enhanced hydroxyl binding at the heterostructure interfaces. Consequently, these factors synergistically accelerate the HOR kinetics on Ru-MoC/C and promote the stability of Ru-MoC/C.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"27 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matthias Krause, Carlos Romero-Muñiz, Oleksandr Selyshchev, Dietrich RT Zahn, Ramon Escobar-Galindo
Excitation wavelength-dependent Raman spectroscopy, optical spectroscopy, and density functional theory (DFT) calculations with hybrid functionals were used to analyse the electronic structure of defects in transparent conductive oxide SnO2:Ta (1.25 at.% Ta) thin films. Based on Raman excitation profiles of the characteristic D1 and D2 defect modes of two tin vacancy VSn- and one oxygen interstitial Oi-type defects, we derive the corresponding defect-induced electronic transitions of the involved defect states. The DFT calculations reveal additional density-of-states for the three point defects at the top of the valence band (VB) in comparison to defect-free SnO2 and SnO2:Ta. The largest distortion of the VB electronic structure is caused by the VSn-type defect with the farest possible distance from the Ta dopant in the studied 96-atom supercell, and the smallest one by the Oi-type defect. Accordingly, the amount of VB splitting shows a reverse order as the electronic transition energies. From the projected defect-density-of-states we find a delocalized nature of the VSn- and a localized nature of the Oi-type defects, respectively, accounting for the different degree of distortion of the SnO2:Ta electronic structure. Based on these complementary experimental and theoretical results the electronic structure of point defects in transparent conductive oxide SnO2:Ta was elucidated in very much detail. The presented approach has great potential to resolve the ongoing controversy about point defects in SnO2.
{"title":"Resonant defect states of transparent conductive oxide SnO2:Ta revealed by excitation wavelength-dependent Raman spectroscopy and hybrid functional DFT calculations","authors":"Matthias Krause, Carlos Romero-Muñiz, Oleksandr Selyshchev, Dietrich RT Zahn, Ramon Escobar-Galindo","doi":"10.1039/d4ta08693g","DOIUrl":"https://doi.org/10.1039/d4ta08693g","url":null,"abstract":"Excitation wavelength-dependent Raman spectroscopy, optical spectroscopy, and density functional theory (DFT) calculations with hybrid functionals were used to analyse the electronic structure of defects in transparent conductive oxide SnO<small><sub>2</sub></small>:Ta (1.25 at.% Ta) thin films. Based on Raman excitation profiles of the characteristic D<small><sub>1</sub></small> and D<small><sub>2</sub></small> defect modes of two tin vacancy V<small><sub>Sn</sub></small>- and one oxygen interstitial O<small><sub>i</sub></small>-type defects, we derive the corresponding defect-induced electronic transitions of the involved defect states. The DFT calculations reveal additional density-of-states for the three point defects at the top of the valence band (VB) in comparison to defect-free SnO<small><sub>2</sub></small> and SnO<small><sub>2</sub></small>:Ta. The largest distortion of the VB electronic structure is caused by the V<small><sub>Sn</sub></small>-type defect with the farest possible distance from the Ta dopant in the studied 96-atom supercell, and the smallest one by the O<small><sub>i</sub></small>-type defect. Accordingly, the amount of VB splitting shows a reverse order as the electronic transition energies. From the projected defect-density-of-states we find a delocalized nature of the V<small><sub>Sn</sub></small>- and a localized nature of the O<small><sub>i</sub></small>-type defects, respectively, accounting for the different degree of distortion of the SnO<small><sub>2</sub></small>:Ta electronic structure. Based on these complementary experimental and theoretical results the electronic structure of point defects in transparent conductive oxide SnO<small><sub>2</sub></small>:Ta was elucidated in very much detail. The presented approach has great potential to resolve the ongoing controversy about point defects in SnO<small><sub>2</sub></small>.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"216 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143744788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lin Sun, Lijun Wang, Yang Liu, Hongyu Wang, Zhong Jin
In contrast to nanosilicon, micron-sized silicon anodes have regained widespread attention due to their high energy density, favorable processability, and reduced side reactions. However, these anodes are plagued by several significant challenges. They undergo substantial volume changes, suffer from sluggish lithium-ion transport kinetics and the loss of electrical contact. In this study, micron-sized porous silicon (pSi) obtained through acid etching of Al60Si40 alloy was utilized as the starting material. A novel approach combining high-energy ball milling and wet chemistry methods was adopted to dope Ge atoms into pSi and modify it with liquid GaInSn metal (LM) alloy (Designated as pSi/Ge@LM). The incorporation of Ge heteroatoms and LM offers multiple benefits. Firstly, it enhances the tap density of pSi. Secondly, it effectively boosts the electron transport performance of the material. Moreover, the excellent metallic properties and liquid fluidity of LM endow it with a unique "self-healing" function. Both the half-cells and full-cells assembled with pSi/Ge@LM electrode demonstrate outstanding electrochemical performance. Specifically, In the half-cells, when cycled at a current density of 1 A g-1 for 400 times, the pSi/Ge@LM electrode retains a remarkably high specific capacity of 1011 mAh g-1. Even at a high current density of 3 A g-1, it still delivers a reversible capacity of over 900 mAh g-1. It is anticipated that this research will offer novel insights and valuable guidance for the development of high-energy-density micron-sized silicon anodes.
{"title":"Synergistic Engineering of Micron-sized Porous Silicon Anodes via Ge Doping and Liquid Metal Alloy Modification for High-energy-density Lithium-ion Batteries","authors":"Lin Sun, Lijun Wang, Yang Liu, Hongyu Wang, Zhong Jin","doi":"10.1039/d5ta00298b","DOIUrl":"https://doi.org/10.1039/d5ta00298b","url":null,"abstract":"In contrast to nanosilicon, micron-sized silicon anodes have regained widespread attention due to their high energy density, favorable processability, and reduced side reactions. However, these anodes are plagued by several significant challenges. They undergo substantial volume changes, suffer from sluggish lithium-ion transport kinetics and the loss of electrical contact. In this study, micron-sized porous silicon (pSi) obtained through acid etching of Al60Si40 alloy was utilized as the starting material. A novel approach combining high-energy ball milling and wet chemistry methods was adopted to dope Ge atoms into pSi and modify it with liquid GaInSn metal (LM) alloy (Designated as pSi/Ge@LM). The incorporation of Ge heteroatoms and LM offers multiple benefits. Firstly, it enhances the tap density of pSi. Secondly, it effectively boosts the electron transport performance of the material. Moreover, the excellent metallic properties and liquid fluidity of LM endow it with a unique \"self-healing\" function. Both the half-cells and full-cells assembled with pSi/Ge@LM electrode demonstrate outstanding electrochemical performance. Specifically, In the half-cells, when cycled at a current density of 1 A g-1 for 400 times, the pSi/Ge@LM electrode retains a remarkably high specific capacity of 1011 mAh g-1. Even at a high current density of 3 A g-1, it still delivers a reversible capacity of over 900 mAh g-1. It is anticipated that this research will offer novel insights and valuable guidance for the development of high-energy-density micron-sized silicon anodes.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"12 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143758539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：