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解析单颗粒电化学分步电子转移步骤用于识别电催化剂本征活性
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作者 孙泽晖 来壮壮 +2 位作者 赵影影 陈建富 马巍 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第5期262-271,共10页
揭示电催化剂本征活性对于量化其构-效关系至关重要.传统的整体表征方法只能提供大量纳米颗粒(NP)的平均性能,并且通常难以排除添加剂的贡献.单颗粒碰撞电化学(SNCE)技术能够有效地在单NP水平上揭示电催化剂活性.尽管SNCE领域已取得了... 揭示电催化剂本征活性对于量化其构-效关系至关重要.传统的整体表征方法只能提供大量纳米颗粒(NP)的平均性能,并且通常难以排除添加剂的贡献.单颗粒碰撞电化学(SNCE)技术能够有效地在单NP水平上揭示电催化剂活性.尽管SNCE领域已取得了很大的研究进展,但目前人们对其反应中的电子转移过程认识尚不充分,难以提供NPs结构与活性之间的定量关系.本文以铂纳米颗粒(PtNPs)氧还原反应(ORR)作为SNCE过程的模型体系,通过构建功能化锥形碳微米电极(CNE)界面,有效地调控了ORR电催化过程,揭示了SNCE分步电子转移在调节单个PtNP表观ORR活性中的重要作用.分别采用化学刻蚀和元素功能化技术调控CNE界面的表面粗糙度和氮元素掺杂组成,构筑了光滑碳电极(s-CNE)、粗糙碳电极(r-CNE)、光滑氮掺杂碳电极(sN-CNE)和粗糙氮掺杂碳电极(rN-CNE)四种功能化电极界面.实验表明,单个PtNP在s-CNE、r-CNE、sN-CNE和rN-CNE这四种功能化CNE界面上产生的ORR电流强度依次增大(即s-CNE<r-CNE<sN-CNE<rN-CNE),且在rN-CNE表面达到了扩散控制的极限电流.这一发现证明了,通过对电极界面进行功能化处理可以显著提升PtNPs的ORR性能,这是由于单个PtNP的ORR总反应速率受决速步控制.密度泛函理论计算和表征结果表明,对电极界面进行表面粗糙化处理或氮元素掺杂可以分别调控SNCE电催化中的单步电子转移过程,即增强NP与电极间的电子传递速率或NP的异相动力学速率.为深入解析这一复杂过程,构建了一个多物理场理论模型.该模型将NP与电极间的电子转移、NP表面的异相电子转移以及溶液中的物质传递作为SNCE过程中的连续步骤.通过将理论模拟与高分辨电化学测量相结合,成功量化了SNCE分步电子转移步骤的相应参数,包括NP与电极间的接触电阻、NP的异相动力学常数以及NP与电极间的吸附概率,从而明确了提高电催化剂本征活性的决速步.综上所述,本文通过单颗粒电化学测量和多物理场理论模拟,深入探究了SNCE分步电子转移过程,在单NP水平上识别了电催化剂的本征活性.同时,利用分步电子转移模型量化了电催化剂构-效关系,从而为合理设计和开发高效纳米催化剂提供启示. 展开更多
关键词 单颗粒 电催化剂 电子转移 决速步 本征活性
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Navigating interdisciplinary research:Historical progression and contemporary challenges
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作者 Xiaoqiang Li Fen Cai +3 位作者 Jintao Bao Yuqing Jian zehui sun Xin Xie 《Journal of Data and Information Science》 CSCD 2024年第3期14-28,共15页
Interdisciplinary research plays a crucial role in addressing complex problems by integrating knowledge from multiple disciplines.This integration fosters innovative solutions and enhances understanding across various... Interdisciplinary research plays a crucial role in addressing complex problems by integrating knowledge from multiple disciplines.This integration fosters innovative solutions and enhances understanding across various fields.This study explores the historical and sociological development of interdisciplinary research and maps its evolution through three distinct phases:pre-disciplinary,disciplinary,and post-disciplinary.It identifies key internal dynamics,such as disciplinary diversification,reorganization,and innovation,as primary drivers of this evolution.Additionally,this study highlights how external factors,particularly the urgency of World War II and the subsequent political and economic changes,have accelerated its advancement.The rise of interdisciplinary research has significantly reshaped traditional educational paradigms,promoting its integration across different educational levels.However,the inherent contradictions within interdisciplinary research present cognitive,emotional,and institutional challenges for researchers.Meanwhile,finding a balance between the breadth and depth of knowledge remains a critical challenge in interdisciplinary education. 展开更多
关键词 Interdisciplinary research Historical sociology Development phases Interdisciplinary challenges
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Unveiling the intrinsic properties of single NiZnFeO_x entity for promoting electrocatalytic oxygen evolution
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作者 Zhihao Gu Jiabo Le +3 位作者 Hehe Wei zehui sun Mahmoud Elsayed Hafez Wei Ma 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第4期181-186,共6页
Although considerable research efforts have been devoted to the design and development of non-noble electrocatalysts for oxygen evolution reaction(OER), substantial enhancement of OER performance with commercial-scale... Although considerable research efforts have been devoted to the design and development of non-noble electrocatalysts for oxygen evolution reaction(OER), substantial enhancement of OER performance with commercial-scale water electrolysis remains a big challenge. This could result from the difficulties in detecting the intrinsic properties and overlooking the assembly process for electrochemical OER process. Here, we employ a microjet collision method to investigate the intrinsic OER activities of individual NiZnFeO_x entities with and without a moderate magnetic field. Our results demonstrate that single NiZnFeO_x nanoparticles(NPs) show the excellent OER performance with a lowest onset potential(~1.35 V vs. RHE) and a greatest magnetic enhancement(~118%) among bulk materials, single agglomerations and NPs. Furthermore, we explore the utility of theoretical investigation by density functional theory(DFT)calculations for studying OER process on NiZnFeO_x surfaces without and with spin alignment, indicating monodispersed NiZnFeO_xNPs with totally spin alignment facilitates the OER process under the external magnetic field. It is found that the well-dispersion of NiZnFeO_x NPs would increase the electrical conductivity and the surface spin state, resulting in promoting their OER activities. This work provides a test for uncovering the essential roles of NPs assembly to a significant promotion of their magnet-assisted OER. 展开更多
关键词 Single entity OER Magnetic enhancement ELECTROCATALYSIS Well-dispersion
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探究过氧化氢酶在有无磁场下的构象动力学
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作者 丁清丹 孙泽晖 马巍 《Science Bulletin》 SCIE EI CAS CSCD 2023年第21期2564-2573,M0005,共11页
酶分子的构象变化对其催化活性至关重要,但这些自发的、非同步的构象波动很难通过整体系综的测量方法获得.本文采用无标记的单体碰撞电化学方法实时追踪了单个过氧化氢酶分子在有无磁场下双氧水降解过程中酶活性的动态波动.利用高分辨... 酶分子的构象变化对其催化活性至关重要,但这些自发的、非同步的构象波动很难通过整体系综的测量方法获得.本文采用无标记的单体碰撞电化学方法实时追踪了单个过氧化氢酶分子在有无磁场下双氧水降解过程中酶活性的动态波动.利用高分辨电化学测量,探测单个过氧化氢酶分子在碳纳米电极上的电化学信号,解析观察到的3种不同特征电流轨迹,获取了酶分子在催化反应过程中亚毫秒时间尺度上构象变化.在施加磁场条件下,由于过氧化氢酶的铁活性中心构象运动受到限制,只观测到单个过氧化氢酶分子呈现出几乎一致的单峰信号.进一步,通过将高分辨电化学信号和多物理场模拟模型相结合研究了过氧化氢酶分子在有无磁场条件下的催化反应动力学信息,并计算了过氧化氢酶催化反应的最大催化速率和构象转变速率.该工作为现有的单分子酶学引入了一种新方法,有助于深入理解酶的催化反应机制. 展开更多
关键词 催化反应过程 活性中心 过氧化氢酶 酶催化反应 催化反应动力学 电化学测量 系综 构象变化
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High loading cotton cellulose-based aerogel self-standing electrode for Li-S batteries 被引量:8
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作者 Heng Mao Limin Liu +11 位作者 Lei Shi HuWu Jinxin Lang Ke Wang Tianxiang Zhu Yiyang Gao zehui sun Jing Zhao Guoxin Gao Dongyang Zhang Wei Yan Shujiang Ding 《Science Bulletin》 SCIE EI CAS CSCD 2020年第10期803-811,M0003,共10页
Lithium-sulfur(Li-S) batteries have attracted considerable attention due to their high energy density(2600 Wh kg-1). However, its commercialization is hindered seriously by the low loading and utilization rate of sulf... Lithium-sulfur(Li-S) batteries have attracted considerable attention due to their high energy density(2600 Wh kg-1). However, its commercialization is hindered seriously by the low loading and utilization rate of sulfur cathodes. Herein, we designed the cellulose-based graphene carbon composite aerogel(CCA) self-standing electrode to enhance the performance of Li-S batteries. The CCA contributes to the mass loading and utilization efficiency of sulfur, because of its unique physical structure: low density(0.018 g cm-3), large specific surface area(657.85 m2 g-1), high porosity(96%), and remarkable electrolyte adsorption(42.25 times). Compared to Al(about 49%), the CCA displayed excellent sulfur use efficiency(86%) and could reach to high area capacity of 8.60 mAh cm-2 with 9.11 mgS loading. Meanwhile,the CCA exhibits the excellent potential for pulse sensing applications due to its flexibility and superior sensitivity to electrical response signals. 展开更多
关键词 Cellulose-based graphene aerogel Self-standing electrode High sulfur loading Lithium-sulfur battery Pulse sensing
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Recent advances in nanocollision electrochemistry 被引量:1
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作者 zehui sun Mahmoud Elsayed Hafez +1 位作者 Wei Ma Yi-Tao Long 《Science China Chemistry》 SCIE EI CAS CSCD 2019年第12期1588-1600,共13页
Ensemble averaging measurements obscure the link between the electrochemical performance and the specific properties of an individual because of the interplay of inhomogeneity and heterogeneity.Nanocollision electroch... Ensemble averaging measurements obscure the link between the electrochemical performance and the specific properties of an individual because of the interplay of inhomogeneity and heterogeneity.Nanocollision electrochemistry has attracted increasing interest because of its extremely high sensitivity,revealing the intrinsic properties of individual entities that are masked in the traditional ensemble measurements.In this perspective review,we summarized the recent developments in nanocollision-based single entity electrochemistry and photoelectrochemistry,the combined nanocollision electrochemistry with the other complementary techniques,as well as accurate data process.In closing,future challenges,opportunities,and destinations related to nanocollison electrochemistry were discussed. 展开更多
关键词 nanocollision electrochemistry single entity photoelectrochemical reaction big data analysis
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