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Rare Metals 2023年第4期42卷 1186-1194页

作者： Xiao Xiao Hui Zhao Lin-Feng Li Bing-Liang Qu Yu-Lian Wu Yin-Ling Zhu Bei-Bei Chen Gang Pan School of Chemistry and Environment Guangdong Ocean UniversityZhanjiang524088China Research Center for Coastal Environmental Protection and Ecological Resilience Guangdong Ocean UniversityZhanjiang524088China College of Coastal Agricultural Science Guangdong Ocean UniversityZhanjiang524088China School of Humanities York St John UniversityLord Mayor’s WalkYorkYO317EXUK

To realize the commercialize of rechargeable Zn-air battery(RZAB),developing metal-free bifunctional electrocatalysts with satisfactory activity for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is one of the emerging issues.Herein,a prawn shells-derived N-enriched porous carbon(PSNC)is synthesized via an ion exchange coupled biomimetic selfsacrificing template strategy.The resulting PSNC displays unique functional components,including the interconnected macro-meso-micropores structure to shorten charge and mass transfer pathway,high content of pyridinic and graphitic nitrogen to construct rich catalytic active site and improve conductivity.As electrocatalysts in alkaline condition,the optimized PSNC-0.8 achieves excellent bifunctional catalytic propriety with a narrow potential gap(ΔE)value of 0.80 V.Meanwhile,PSNC-0.8-based RZAB displays a high peak power density of 176.5 mW·cm^(-2)and considerable cycling durability with a small battery efficiency delay of 6.5%after 480 cycles(320 h).This study enlightens a simple and effective conception to design high-performance metal-free bifunctional electrocatalysts from seafood waste.

关键词： Rechargeable Zn-air battery(RZAB) Bifunctional electrocatalyst N-enriched porous carbon Biomineral self-sacrificial template ion exchange

新型离子交换法制备具有高倍率和高强度钠离子存储性能的本征赝电容正极材料Na_(0.44)MnO_(2)

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Science China Materials 2023年第10期66卷 3810-3816页

作者：曹宇舸肖美静董武杰蔡天逊毕辉黄富强 State Key Laboratory of High-Performance Ceramics and Superfine Microstructures Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

钠离子电池因其成本低、资源丰富等优点而成为新一代储能设备.在各种正极中,隧道型Na_(0.44)MnO_(2)因其较大的Na^(+)通道,被认为是快速充电电池的合适正极材料,但仍然存在Na^(+)动力学缓慢等问题.本文首次提出了一种Na_(0.44)MnO_(2)... 详细信息

钠离子电池因其成本低、资源丰富等优点而成为新一代储能设备.在各种正极中,隧道型Na_(0.44)MnO_(2)因其较大的Na^(+)通道,被认为是快速充电电池的合适正极材料,但仍然存在Na^(+)动力学缓慢等问题.本文首次提出了一种Na_(0.44)MnO_(2)的新型离子交换方法,通过调节合成条件,可以很好地控制K^(+)残余量和Na_(0.44)MnO_(2)的尺寸.结果表明,Na_(0.44)MnO_(2)结构中的残留K^(+)扩大了Na^(+)的输运通道,小颗粒形貌缩短了Na^(+)的迁移距离,且晶体中的带状缺陷界面进一步加速了Na^(+)的输运.获得的Na_(0.44)MnO_(2)具有本征赝电容特性,在2-4 V和20 C电流下有79.0 mA h g^(-1)的优异倍率性能.长期循环测试表明,20 C下1000次循环的保持率为98.1%,0.5 C下200次循环的保持率为96.3%.本工作为用于快速充电储能装置的高倍率、高稳定性Na_(0.44)MnO_(2)正极的大规模生产提供了一条新途径.

关键词： Na_(0.44)MnO_(2)cathode sodium-ion battery high rate capability ion exchange

First-principle study of Ba isotopic fractionation during ion exchange processes

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Acta Geochimica 2022年第1期41卷 121-131页

作者： Xin-Yue Ji Yan-Fang Wang Le-Cai Xing Jian Liu Peng-Dong Wang Tian-Di Zhang Hao-Nan Zhao School of Earth Science and Engineering Hebei University of EngineeringHandan 056038China Key Laboratory of Resource Survey and Research of Hebei Province Hebei University of EngineeringHandan 056038China

The potential utilization and development of the Ba isotope tool depend on an accurateδ^(137/134)Ba determination of the samples.During the chemical purification,whether the adsorption process on the surface of the ionexchange resin could lead to the Ba isotopic fractionation and the degree of fractionation directly influence the accurateδ^(137/134)Ba determination.In the present work,first-principles calculations based on the density functional theory were used to quantify the Ba isotopic equilibrium fractionation factor between the aqueous solution and the resin in the acid leaching process.By constructing and optimizing the geometric configurations of Ba-containing species,Ba(H_(2)O)_(n)^(2+),Ba(H_(2)O)_(n)Cl_(2),Ba(H_(2)O)_(n)(NO_(3))2,and the adsorbed Ba^(2+)on the surface of the resin,extracting the harmonic vibrational frequencies,we finally at 298 K obtained the fractionations,Δ^(137/134)Ba_(soln-ads)=0.07‰,Δ^(137/134)Ba_(Ba(H_(2)O)_(n)Cl_(2)-ads)=0.05‰,andΔ^(137/134)-Ba^(Ba(H_(2)O)_(n)(NO_(3))2-ads)=0.02‰.Overall,there were almost no Ba isotope fractionations during leaching.Although the Ba isotope fractionation can be magnified by the Rayleigh fractionation process in purification,the difference inδ137/134Ba between the initial and final stages did not exceed0.060‰(or 0.045‰)when leaching the standard sample with HCl or HNO_(3),which is equal to or less than the accuracy of Ba isotopic analysis.At a common yield of89.75%,Ba isotopic fractionation induced by incomplete recovery was 0.015‰for HCl(or 0.011‰for HNO_(3)).Finally,if the influence of an incomplete recovery on theδ137/134Ba determination needs to be ignored,the recovery is suggested to be not less than 67%for HCl(or 46%for HNO_(3)).

关键词： ion exchange Barium Equilibrium isotopic fractionation First-principles calculations Rayleigh fractionation

Defective layered Mn-based cathode materials with excellent performance via ion exchange for Li-ion batteries

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Journal of Energy Chemistry 2023年第7期82卷 537-546,I0012页

作者： Yongheng Si Kun Bai Yaxin Wang Han Lu Litong Liu Ziyan Long Yujuan Zhao Beijing Key Laboratory for Green Catalysis and Separation Department of ChemistryThe Faculty of Environment and LifeBeijing University of TechnologyBeijing 100124China

Defective layered Mn-based materials were synthesized by Li/Na ion exchange to improve their electrochemical activity and Coulombic efficiency.The annealing temperature of the Na precursors was important to control the P3-P2 phase transition,which directly affected the structure and electrochemical characteristics of the final products obtained by ion exchange.The O3-Li_(0.78)[Li_(0.25)Fe_(0.075)Mn_(0.675)]O_(δ) cathode made from a P3-type precursor calcined at 700℃ was analyzed using X-ray photoelectron spectrometry and electron paramagnetic resonance.The results showed that the presence of abundant trivalent manganese and defects resulted in a discharge capacity of 230 mAh/g with an initial Coulombic efficiency of about 109%.Afterward,galvanostatic intermittent titration was performed to examine the Li^(+) ion diffusion coefficients,which affected the reversible capacity.First principles calculations suggested that the charge redistribution induced by oxygen vacancies(OV_(s))greatly affected the local Mn coordination environment and enhanced the structural activity.Moreover,the Li-deficient cathode was a perfect match for the pre-lithiation anode,providing a novel approach to improve the initial Coulombic efficiency and activity of Mn-based materials in the commercial application.

关键词： ion exchange Defective cathode materials Oxygen vacancies Initial coulombic efficiency DFT calculations

Influence of Al_(2)O_(3)/SiO_(2) Ratio on the Structure and Properties of Na^(+)/K^(+)ion exchange Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) Glasses

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 606-612页

作者：吴建磊 CHEN Junzhu TIAN Xiaokun LI Jiahao GAO Wenkai YUE Yunlong 康俊峰 School of Materials Science and Engineering University of JinanJinan 250022China CDGM GLASS Co.LTD Chengda 610199China

In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were investigated.The results showed that,with increasing Al_(2)O_(3)/SiO_(2) ratio,the simple structural units Q_(1) and Q_(2) transformed into highly aggregated structural units Q_(3) and Q_(4),indicating the increase of polymerization degree of glass network.Meanwhile,the coefficient of thermal expansion decreased from 9.23×10^(-6)℃^(-1) to 8.88×10^(-6)℃^(-1).The characteristic temperatures such as melting,forming,softening and glass transition temperatures increased with the increase of Al_(2)O_(3)/SiO_(2) ratio,while the glasses working temperature range became narrow.The increasing Al_(2)O_(3)/SiO_(2) ratio and prolonging ion-exchange time enhanced the surface compressive stress(CS)and depth of stress layer(DOL).However,the increase of ion exchange temperature increased the DOL and decreased the CS affected by stress relaxation.There was a good linear relationship between stress relaxation and surface compressive stress.Chemical strengthening significantly improved the hardness of glasses,which reached the maximum value of(622.1±10)MPa for sample with Al_(2)O_(3)/SiO_(2) ratio of 0.27 after heat treated at 410℃for 2 h.

关键词： network structure viscosity ion exchange aluminosilicate glass

A two-parameter model for ion exchange process of ion-adsorption type rare earth ores

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Journal of Rare Earths 2020年第11期38卷 1251-1256,I0004页

作者： Ping Long Guanshi Wang Chao Zhang Ying Huang Sihai Luo School of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Cooperative Innovation Center of Efficient Development and Application for ionic Rare Earth Resources Jiangxi University of Science and TechnologyGanzhou 341000China School of Architectural and Surveying and Mapping Engineering Jiangxi University of Science and TechnologyGanzhou 341000China

The establishment of a mathematical model for the ion exchange process is key to creating a theoretical basis for the mining of ion-adsorption type rare earth ores.Ore samples from Xinfeng,Xunwu and Anyuan were used as the test ore samples in the present study and equilibrium batch tests of ore sample leaching using various ammonium sulfate concentrations were performed.The results show that,after leaching,there is a negative exponential relationship between the ratio of the solid-phase rare earth ion concentration to the aqueous-phase rare earth ion concentration and the initial ammonium ion concentration.However,there is a linear relationship between the natural logarithm of the ratio of the solidphase ammonium ion concentration to the aqueous-phase ammonium ion concentration and the initial ammonium ion concentration.Based on the above two functional relationships,a two-parameter model for the equilibrium ion exchange process of ion-adsorption type rare earth ores was established.Using the established model to analyze the test data the model error for the Xunwu ore sample is found to be less than 5%.The proposed model is more accurate compared with the Kerr model.The two-parameter model proposed in this study provides theoretical support for the numerical simulation of column leaching(in-situ leaching)of ion-adsorption type rare earth ores.

关键词： ion-adsorption type rare earth ores ion exchange Empirical model

Recent Progress in Developing Crystalline ion exchange Materials for the Removal of Radioactive ions

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Chinese Journal of Structural Chemistry 2020年第12期39卷 2157-2171,2056页

作者：唐俊豪孙海燕马文冯美玲黄小荥 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China

The nuclear fuel cycle inevitably generates a large amount of radioactive waste liquid,which will pose a serious threat to the ecological environment and human health.ion exchange method has received wide attention for its easy operation,low cost and no secondary pollution.However,the effective removal of radioactive ions from complex solutions still remains a serious challenge due to their environmental mobility and radiotoxicity.We have developed an efficient strategy to construct crystalline ion-exchange materials by inducing layered or three-dimensional microporous anionic frameworks by organic cations that can be effectively exchanged by radioactive metal ions.This type of materials can be applied effectively to the removal of radioactive ions from complex solutions and the removal mechanism has been deeply clarified by means of single crystal structure analyses,theoretical calculations,etc.This review summarizes our recent progress in the study of synthesis,structures and properties of radioactive ion removals for such type of crystalline ion-exchange materials.

关键词： ion exchange crystalline materials metal chalcogenide vanadate MOF organic amine radionuclide remediation

A strategy for highly dispersed Mo2C/MoN hybrid nitrogen- doped graphene via ion-exchange resin synthesis for efficient electrocatalytic hydrogen reduction

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Nano Research 2018年第9期11卷 4535-4548页

作者： Jiabo Wang Weilin Chen Ting Wang Nasen Bate Chunlei Wang Enbo Wang Key Laboratory of Polyoxometalate Science of the Ministry of Education Faculty of Chemistry Northeast Normal University Changchun 130024 China Autonomous Region Level Experimental Teaching Demonstration Center Yili Normal University Wning 835000 China Library of Northeast Normal University Changchun 130024 China

Molybdenum carbide/molybdenum nitride hybrid N-doped graphene （abbreviated as Mo2C/MoN/NG）, as an efficient electrocatalyst for the hydrogen evolution reaction （HER）, was synthesized via simple ion-exchange resin synthesis followed by a two-step annealing process, which increased the dispersion degree of the electrocatalyst＇s active sites on the support skeleton and simplified the synthetic conditions. Additionally, N-doped graphene （NG） enhanced the electron transfer and reduced the inner resistance. The material has a graphene-like morphology and highly dispersed Mo2C/MoN nanoparticles about 2 nm in diameter on the NG. X-ray photoelectron spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy revealed that Mo2C/MoN/NG consisted of Mo2C and MoN composited together. Finally, Mo2C/MoN/NG exhibited remarkable performance as an electrocatalyst for the HER with a small overpotential of 78.82 mV and a small Tafel slope of 39.3 mV.dec^-1 in a 0.5 mol.L-1 H2SO4 solution. Its activity was approximately 30% lower than that of 20% Pt/C and 60% higher than that of NG. Also, it exhibited a low onset overpotential of 24.82 mV, which is similar to the theoretical HER potential. Our work provides a foundation for advanced HER applications of molybdenum compounds.

关键词： polymolybdate hydrogen evolution reaction ion exchange electrocatalyst Tafel slope

Synthesis and ion exchange properties for Cs^+ of ammonium-type mordenite

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Rare Metals 2015年第10期34卷 752-756页

作者： Dian-Quan Dong Jian-Guo Zheng Xian-Lian Han College of Chemical Engineering School of Qingdao University of Science and Technology

Cesium content in the seawater is 3.0 9 10-4 mg·L-1, and ammonium-type mordenite was used to exchange cesium from cesium source. K-type mordenite was obtained by hydrothermal synthesis method. After ammonium-modified, ion exchange properties such as saturated ion exchange capacities and selectivity coefficients for alkali metal ions were determined. At the same time, ion exchange isothermal curves of ammonium-type mordenite for Cs+ and NH4+ were determined at 25°C.Pitzer electrolyte solution theory was used to work out activity coefficients of the system, and the Kielland diagram of the ion exchange system was obtained. The calculated equilibrium constant(Ka) and ion free enthalpy(DG0) of mordenite for Cs+ and NH4+ are 1.455 and -930.3J·mol-1, respectively, indicating that ion exchange process of ammonium-type mordenite for cesium is a spontaneous process.

关键词： ion exchange Thermodynamics Mordenite Cesium

Study of selectively buried ion-exchange glass waveguides using backside masking

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Chinese Optics Letters 2015年第2期13卷 41-44页

作者：裴重阳王根成杨冰杨龙志郝寅雷江晓清杨建义 Department of Information Science and Electronics Engineering Zhejiang University Cyrus Tang Center for Sensor Materials and Applications Zhejiang University

In this Letter, we study the characteristics of a selectively buried glass waveguide that is fabricated by the backside masking method. The results show that the surface region appears when the width of the backside mask is larger than 7 mm. Here, the glass substrate is 1.5 mm thick. It is also found that the buried depth evolution of the transition region remains almost unchanged and is independent of the width of the backside mask. The loss of the transition region is only 0.28 d B at the wavelength of 1.55 μm if the surface condition is good enough.

关键词： ion exchange Substrates Waveguides