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Developing in situ Electron paramagnetic resonance characterization for understanding electron transfer of rechargeable batteries

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Nano Research 2023年第10期16卷 11992-12012页

作者： Bin Wang Wanli Wang Kang Sun Yujie Xu Yi Sun Qiang Li Han Hu Mingbo Wu State Key Lab of Heavy Oil Processing Institute of New EnergyCollege of Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580China Institute of Chemical Industry of Forest Products Chinese Academy of ForestryNanjing 210042China College of Physics Qingdao UniversityQingdao 266071China

Electrochemical energy storage devices are pivotal in achieving“carbon neutrality”by enabling the storage of energy generated from renewable sources.To facilitate the development of these devices,it is important to gain insight into the underlying the single-/multi-electron transfer process.This can be achieved through in-time detection under operational conditions,but there are limited tools available for monitoring electron transfer under operando conditions.Electron paramagnetic resonance(EPR)is a powerful technique that can meet these expectations,as it is highly sensitive to unpaired electrons and can detect changes of paramagnetic centres.Despite the long history of in situ electrochemical EPR research,its potential has been surprisingly underutilized due to the need for strict operando cell design under special testing conditions.This review comprehensively summarizes recent efforts to understand energy storage mechanisms using in situ/operando EPR,with the aim of drawing researchers’attention to this powerful technique.After introducing the fundamental principles of EPR,we describe the critical advances made in detecting batteries using operando EPR,along with the remaining challenges and opportunities for future development of this technology in batteries.We emphasize the need for strict operando cell design and the importance of designing experiments that closely mimic real-world conditions.We believe that this review will provide innovative solutions to solve tough problems that researchers may encounter during their battery research,and ultimately contribute to the development of more efficient and sustainable energy storage devices.

关键词： Electron paramagnetic resonance in situ energy storage battery

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Electron paramagnetic resonance characterization of aluminum ion implantation-induced defects in 4H-SiC

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Nanotechnology and Precision Engineering 2019年第4期2卷 157-162页

作者： Xiuhong Wang Zongwei Xua Mathias Rommel Bing Dong Le Song Clarence Augustine TH Tee Fengzhou Fang State Key Laboratory of Precision Measuring Technology&Instruments Tianjin UniversityTianjin 300072China Fraunhofer Institute for Integrated Systems and Device Technology(IISB) Schottkystrasse 10Erlangen 91058Germany Department of Electrical Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Centre of Advanced Research Enabler Facility Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia

Deep-level defects in silicon carbide(SiC)are critical to the control of the performance of SiC electron devices.In this paper,deep-level defects in aluminumion-implanted 4H-SiC after high-temperature annealingwere studied using Electron paramagnetic resonance(EPR)spectroscopy at temperatures of 77 K and 123 K under different illumination conditions.Results showed that the main defect in aluminum ion-implanted 4H-SiC was the positively charged carbon vacancy(VC+),and the higher the doping concentration was,the higher was the concentration of VC+.Itwas found that the type of material defectwas independent of the doping concentration,although more VC+defects were detected during photoexcitation and at lower temperatures.These results should be helpful in the fundamental research of p-type 4H-SiC fabrication in accordance with functional device development.

关键词： Electron paramagnetic resonance Silicon carbide Defects Carbon vacancy

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A low-noise X-band microwave source with digital automatic frequency control for Electron paramagnetic resonance spectroscopy

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Chinese Physics B 2023年第8期32卷 46-51页

作者：贺羽康润琪石致富荣星 CAS Key Laboratory of Microscale Magnetic resonance and School of Physical Sciences University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Chinainstru&Quantumtech(Hefei)Co. LtdHefei 230031China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

We report a new design of microwave source for X-band Electron paramagnetic resonance spectrometer.The microwave source is equipped with a digital automatic frequency control circuit.The parameters of the digital automatic frequency control circuit can be flexibly configured for different experimental conditions,such as the input powers or the quality factors of the resonator.The configurability makes the microwave source universally compatible and greatly extends its application.To demonstrate the ability of adapting to various experimental conditions,the microwave source is tested by varying the input powers and the quality factors of the resonator.A satisfactory phase noise as low as-135 d Bc/Hz at 100-k Hz offset from the center frequency is achieved,due to the use of a phase-locked dielectric resonator oscillator and a direct digital synthesizer.Continuous-wave Electron paramagnetic resonance experiments are conducted to examine the performance of the microwave source.The outstanding performance shows a prospect of wide applications of the microwave source in numerous fields of science.

关键词： Electron paramagnetic resonance X-band microwave source automatic frequency control

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Electron paramagnetic resonance study of amphiphiles partitioning behavior in desiccation-tolerant moss during dehydration

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Chinese Chemical Letters 2007年第7期18卷 865-868页

作者： Shu Jun Xu Wei Hong Chen Ying Wen Chen Cui Fang Wang Yan Wang School of Environmental Science and Engineering Shanghai Jiaotong University Shanghai 200240 China Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

Desiccation tolerance is a crucial characteristic for desert moss surviving in arid regions. Desiccation procedure always induces amphiphiles transferring from the polar cytoplasm into lipid bodies. The behavior of amphiphiles transferring can contribute to the enhancement of desiccation tolerance and the reduction of plasma membrane integrity simultaneously. The effects of amphiphiles partitioning into the lipid phase during water loss has been studied for pollen and seeds using Electron paramagnetic resonance （EPR） spectroscopy. However, desiccation-tolerant high plants occur among mosses, several angiosperms and higher plants seeds or pollens. They have different strategies for survival in dehydration and rehydration. A desiccation-tolerant moss Tortula desertorurn was used to investigate the behaviors of amphiphilic molecules during drying by spin label technology. There are small amount of amphiphilic probes partitioning into membrane during moss leaves dehydration, comparing with that in higher plants. Cytoplasm viscosity changed from 1.14 into glass state only dehydration less than 60 min. Moss leaves lost plasma membrane integrity slightly,from 0.115 to 0.237, occurred simultaneously with amphiphiles partition. The results showed the more advantages of mosses than higher plants in adapting fast dehydration. We propose that EPR spin label is feasible for studying the amphiphiles partitioning mechanisms in membrane protection and damage for desiccation-tolerant mosses.

关键词： Plasma membrane permeability Amphiphiles partition Desiccation tolerance Electron paramagnetic resonance Tortula desertorum broth. Mosses

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Electron paramagnetic resonance ——An effective method to monitor the protein unfolding

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Progress in Natural Science:Materials International 1997年第2期 118-120页

作者：舒占永 Beijing 100101 China Chinese Academy of Sciences Institute of Biophysics State Key Laboratory of Biomacromolecules

Generally, Electron paramagnetic resonance (EPR) can be used to study the metallo-proteins which either contain paramagnetic ions, or could be reconstituted with paramagnetic ions. The substitution or the oxidation-reduction of the metal ions in the enzyme can be monitored visually using EPR through the variation of EPR signals. However, EPR analysis is not sensitive to the

关键词： Electron paramagnetic resonance protein unfolding conformational changes.

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Thermoluminescent response of gamma irradiated Na^(+)–Cu^(+) ionexchanged silicate glass in large dose range

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Nuclear Science and Techniques 2023年第5期34卷 22-32页

作者： Safa Toumi Khaled Farah Laboratoire de Physico‑Chimie des Matériaux Département de PhysiqueFacultédes Sciences de MonastirUniversitéde MonastirMonastirTunisia Institut Supérieur du Transport et de la Logistique de Sousse Universitéde Sousse4023 SousseTunisia Laboratoire de Recherche en Energie et Matière Développement des Sciences Nucléaires(LR16CNSTN02)Centre National des Sciences et Technologies Nucléaires2020 Sidi‑ThabetTunisia

The introduction of metals into vitreous matrices is the origin of various interesting phenomena;in particular,the presence of copper ions in glass has been the subject of considerable research because of its numerous applications.The ion-exchange process is primarily used to introduce copper ions into glass matrices.The thermoluminescence(TL)of silicate glass was studied to evaluate its potential as gamma-sensitive material for dosimetric applications;the effect of copper doping on the thermoluminescent sensitivity was investigated using the Cu-Na ion-exchange technique for different concentrations and doping conditions,over a wide dose range of 10 mGy to 100 kGy.The results showed that Cu doping significantly improved the sensitivity of the glasses to gamma radiation.After the ion-exchange,two peaks appeared in the glow curves at approximately 175 and 230°C,respectively,which possibly originated from the Cu^(+) centers,along with a weak TL peak at around 320℃.We also attempted to explain the origin of the observed thermoluminescence by exploiting the Electron paramagnetic resonance(EPR)spectra.The results clearly show quenching of the TL emission with increasing copper concentrations.The present work indicates that the thermoluminescence response of these glasses to gamma rays can be reasonably measured in the range of 0.001-100 kGy.This study also facilitates the understanding of the basic TL mechanism in this glass system.

关键词： Cu-Na ion-exchange Silicate glass Thermoluminescence Gamma irradiation Electron paramagnetic resonance

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Correlations between trace elements in pyrite and gold mineralization of gold deposits on the North China platform

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Acta Geochimica 2023年第6期42卷 1079-1103页

作者： Jianzhao Yin Ying Sun Haoyu Yin Hongyun Shi James Sparling Yuhong Chao Shoupu Xiang College of Earth Sciences Jilin UniversityChangchun 130061China Wuhan Institute of Technology Wuhan 430074China College of Geoexploration Science and Technology Jilin UniversityChangchun 130062China Guinea Westfield Mining Company-Sarlu Jinzhong 031300China Orient Resources Ltd. RichmondBC V7A 4V5Canada Hochschild Mining Canada Corp. Suite 1700 Park Place666 Burrard StreetVancouverBC V6C 2X8Canada Ganzhongnan Institute of Geology and Mineral Exploration 658 Jiefangxilu RoadNanchang 330002China Silvercorp Metals Inc. Suite 601-Building 1China View Mansion#A2 East GongTi RoadChaoyang DistrictBeijing 100027China

By studying both the microscopic physical and chemical typomorphic characteristics of typical mineral pyrite samples associated with representative gold deposits on the north-central margin of the North China Platform,this paper seeks to identify macroscopic metallogenic mechanisms of gold deposits and to reveal the formation mechanism of lattice gold in pyrite.Typomorphic characteristics of pyrite reveal that pyrite grain size has a negative correlation with gold content.Cubic pyrite,as the dominant crystal form,contains more gold than pentagonal dodecahedral pyrite.Both pyrite crystal forms and chemical compositions indicate that the replacement style of gold deposit formed in a low saturability,low sulfur fugacity,and at temperatures either much higher or much lower than its best forming temperature;comparatively,that of the quartz vein style of gold deposit occurred under conditions with the best temperature,rich in sulfur,and with high sulfur fugacity.The Au/Ag ratios of the pyrites show that both the replacement and quartz vein styles of deposits are mesothermal and hypothermal,while the Co/Ni ratios of the pyrites indicate that the quartz vein style is of magmatic-hydrothermal origin.The X-ray diffraction intensity of pyrite rich in gold is lower than that of pyrite poor in gold at the quartz vein style.In general,with an increase in gold content in pyrite,the total sum intensityΣI decreases.The pyroelectricity coefficient has a negative correlation trend with the values of(Co+Ni+Se+Te)-As and(Co+Ni+Se+Te)/As.The pyrite pyroelectricity of the replacement style is N-type,indicating that it formed under low sulfur fugacity,while that of the quartz vein style is a mixture of P-N types,indicating that it formed under high sulfur fugacity.On the pyroelectricity-temperature diagram,pyrite of the replacement style is mainly distributed between 200 and 270°C,while that of the quartz vein style varies between 90–118 and274–386°C,demonstrating a multistage forming process.In contrast to previous researchers'conclusi

关键词： Unit cell parameter Pyroelectricity Electron paramagnetic resonance Infrared spectrum Pyrite Gold deposit

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EPR study of charge separation associated states and reversibility of surface bound superoxide radicals in SrTiO_(3) photocatalyst

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Journal of Energy Chemistry 2022年第7期31卷 388-393,I0011页

作者： Xianwen Zhang Zheng Li Bin Zeng Can Li Hongxian Han State Key Laboratory of Catalysis and Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

Understanding the processes of charge generation, transfer and capture is important for the design and synthesis of efficient photocatalysts. In this work, light-induced charge separation and effect of O_(2) on electron transfer processes in SrTiO_(3) were investigated by Electron paramagnetic resonance(EPR). It was found that photoinduced electron transfer from O_(2)- to Ti^(4+) produced Ti^(3+) and O- redox radical pairs under vacuum condition. Under oxygen atmosphere, however, surface bound superoxide radicals O_(2)-were formed by electron reduction of adsorbed oxygen at initial photoirradiation stage, and quenched by the reverse electron transfer to Ti^(4+) upon further photoirradiation. Formation of long-lived charge separation associated [Ti^(3+)---O-] species and the reversibility of surface bound superoxide radicals mediating the processes of photogenerated electrons may be accountable for the high activity of SrTiO_(3) in photocatalytic water splitting reaction.

关键词： Photocatalyst Electron paramagnetic resonance Charge separation Superoxide radicals

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Ferromagnetic Exchange Coupling in Ni(Ⅱ)Complexes with a Coordinated Boron-Oxamido Radical:A Result of Spin State Transition

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Chinese Journal of Chemistry 2023年第10期41卷 1163-1169页

作者： Shuxuan Tang Huapeng Ruan Xue Dong Yue Zhao Xinping Wang State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjingJiangsu 210023China SINOPEC(Beijing)Research Institute of Chemical Industry Co. Ltd.Beijing 100013China

A Ni(Ⅱ)coordination complex 1 with a novel boron-oxamido radical ligand was synthesized and isolated.Reactions of 1 with N,N-dimethyl-4-pyridinamine(DMAP)and 4,4'-bpy resulted in 2 and 3,respectively,accompanied by the spin state transition from S=1/2 to S=3/2.Both 2 and 3 were isolated as stable crystals and characterized to feature an S=3/2 spin state,with the S=1 Ni(Ⅱ)atoms ferromagnetically coupled with the ligand-centred radicals,by SQUID measurement and EPR spectroscopy.Complex 3 represents the first example of one-dimensional magnetic chain constructed by S=3/2 Ni(Ⅱ)-radical units.

关键词： Boron radical Nickel Ferromagnetic coupling Electron paramagnetic resonance Magnetic chain

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Surface characterization of metal oxides-supported activated carbon fiber catalysts for simultaneous catalytic hydrolysis of carbonyl sulfide and carbon disulfide

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Journal of Environmental Sciences 2020年第10期32卷 44-54页

作者： Kunlin Li Chi Wang Ping Ning Kai Li Xin Sun Xin Song Yi Mei Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500China Faculty of Chemical Engineering Kunming University of Science and TechnologyKunming 650500China National-Regional Engineering Center for Recovery of Waste Gases from Metallurgical and Chemical Industries Kunming 650500China

The sol–gel method was used to synthesize a series of metal oxides-supported activated carbon fiber (ACF) and the simultaneous catalytic hydrolysis activity of carbonyl sulfide (COS)and carbon disulfide (CS2) at relatively low temperatures of 60°C was tested.The effects of preparation conditions on the catalyst properties were investigated,including the kinds and amount of metal oxides and calcination temperatures.The activity tests indicated that catalysts with 5 wt.%Ni after calcining at 400°C (Ni(5)/ACF(400)) had the best performance for the simultaneous catalytic hydrolysis of COS and CS2.The surface and structure properties of prepared ACF were characterized by scanning electron microscope-energy disperse spectroscopy (SEM-EDS),Brunauer–Emmett–Teller (BET),X-ray diffraction (XRD),carbon dioxidetemperature programmed desorption (CO2-TPD) and diffuse reflectance Fourier transform infrared reflection (DRFTIR).And the metal cation defects were researched by Electron paramagnetic resonance (EPR) method.The characterization results showed that the supporting of Ni on the ACF made the ACF catalyst show alkaline and increased the specific surface area and the number of micropores,then improved catalytic hydrolysis activity.The DRFTIR results revealed that-OH species could facilitate the hydrolysis of COS and CS2;-COO and-C–O species could facilitate the oxidation of catalytic hydrolysate H2S.And the EPR results showed that high calcination temperature conditions provide more active reaction center for the COS and CS2 adsorption.

关键词： Simultaneous catalytic hydrolysis Carbonyl sulfide Carbon disulfide Ni(5)/ACF(400) Surface characterization Electron paramagnetic resonance

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