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Theoretical study on the synergistic mechanism of fe–Mn in sodium-ion batteries

Particuology 2024年第10期93卷 284-290页

作者： yang You Mingliang Yuan School of Mineral Processing and Bioengineering Central South UniversityChangsha410083China

This article conducts first-principles calculations to initially explore the construction of two configurations,NafeO_(2)(NFO)and NaMnO_(2)(NMO),and studies the mixing enthalpies under different fe–Mn *** results indicate that Nafe3/8Mn5/8O_(2)(NFMO)exhibits the most thermodynamically stable *** calculations on the mixing enthalpies and volume changes during the sodium extraction process for NFO,NMO,and NFMO configurations are presented,along with the partial density of states(PDOS)and Bader charges of transition metals(TM)and *** calculations reveal the synergistic mechanism of fe and *** and Mn can engage in more complex electron exchanges during sodium extraction,optimizing the internal electron density distribution and overall charge balance,thereby stabilizing the crystal structure and reducing the migration of fe^(3+)to the sodium layers during deep sodium *** interaction between fe’s 3d electrons and Mn’s 3d electrons through the shared oxygen atoms’2p orbitals occurs in the fe–Mn–O *** interaction can lead to a rebalancing of the electron density around Mn³⁺atoms,mitigating the asymmetric electron density distribution caused by the d4 configuration of the lone Mn³⁺and suppressing the Jahn-Teller effect of Mn^(3+).Moreover,the synergistic effects between fe and Mn can provide a more balanced charge distribution,reducing extreme changes to the charge state of oxygen atoms and decreasing the irreversible oxygen release caused by anionic redox reactions during deep sodium extraction,thereby enhancing the material’s *** in-depth study of the interaction mechanism at the microscopic level when co-doping fe and Mn offers valuable insights for the rational design and development of high-performance cathode materials.

关键词： First-principles calculations Sodium-ionbatteries Layered oxides Nafe_(3/8)Mn_(3/8)O_(2)

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Crystalline-amorphous M@MN_x(M=Co,fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： yang yang Xiao-Chuan Duan Shao-Hui guo Xian-Ming Zhang College of Materials Science and Engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyYuci030600China

Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy ***,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MN_(x)(M=Co,fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-Ng)are synthesized by facile hydrothermal reaction and nitridation *** the nitriding process,metal ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystalline *** Co@CoN_(x)@NC-Ng catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·L^(-1)H_(2)SO_4 and1.0 mol·L^(-1)KOH electrolytes,*** Co@CoN_(x)@NC-Ng retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline *** outstanding HER performance originates from the crystalline-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER *** outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： Hydrogen evolution reaction Electrocatalysts Iron group metals Heterojunction Crystalline-amorphous structure

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Chemical looping reforming of the micromolecular component from biomass pyrolysis via fe_(2)O_(3)@SBA-16

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International Journal of Coal Science & Technology 2024年第3期11卷 120-134页

作者： Yunchang Li Bo Zhang Xiantan yang Bolun yang Shengyong Zhang Zhiqiang Wu Shaanxi Key Laboratory of Energy Chemical Process Intensification School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an710049ShaanxiPeople’s Republic of China

To solve the problems of low gasification efficiency and high tar content caused by solid–solid contact between biomass and oxygen carrier in traditional biomass chemical looping gasification *** decoupling strategy was adopted to decouple the biomass gasification process,and the composite oxygen carrier was prepared by embedding fe_(2)O_(3) in molecular sieve SBA-16 for the chemical looping reforming process of pyrolysis micromolecular model compound methane,which was expected to realize the directional reforming of pyrolysis volatiles to prepare hydrogen-rich *** analysis of the reaction system was carried out based on the gibbs free energy minimization method,and the reforming performance was evaluated by a fixed bed reactor,and the kinetic parameters were solved based on the gas–solid reaction *** analysis verified the feasibility of the reaction and provided theoretical guidance for experimental *** experimental results showed that the reaction performance of fe_(2)O_(3)@SBA-16 was compared with that of pure fe_(2)O_(3) and fe_(2)O_(3)@SBA-15,and the syngas yield was increased by 55.3%and 20.7%respectively,and it had good cycle *** analysis showed that the kinetic model changed from three-dimensional diffusion to first-order reaction with the increase of *** activation energy was 192.79 kJ/mol by *** paper provides basic data for the directional preparation of hydrogen-rich syngas from biomass and the design of oxygen carriers for pyrolysis of all-component chemical looping reforming.

关键词： Biomass pyrolysis Methane Chemical looping reforming Oxygen carrier Kinetic analysis

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Effect of Sc on Al_(3)fe phase and mechanical properties of as-cast AA5052 aluminum alloy

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China Foundry 2024年第3期21卷 257-264页

作者： yang Li Qing Yu fe.g-fe.g Chen Jia-wen He Hong-mei yang Meng-nie Li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAgBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAgBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3fe phase mechanical properties grain boundary

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The degradation of cathodic fe/N/C catalyst in PEMFCs:The evolution of remanent active sites after demetallation

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Journal of Materials Science & Technology 2024年第6期173卷 100-106页

作者： Xiaohua yang Wentao Sun Jiatang Chen yang gao Rongxian Zhang Qun Luo Tao Lyu Lei Du Institut National de la Recherche Scientifique-Énergie Matériaux et Télécommunications J3X 1P7 VarennesQCCanada School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced ferrometallurgy School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Huangpu Hydrogen Energy Innovation Center School of Chemistry and Chemical EngineeringGuangzhou UniversityGuangzhou 510006China

The state-of-the-art fe/N/C catalyst has presented comparable initial cathode performance to the benchmark Pt/C catalyst in proton exchange membrane fuel cells(PEMFCs).However,the major bottleneck is its significant activity decay in real-world PEMFC *** superposed“fast decay”and“slow decay”have been well documented to describe the degradation process of fe/N/C catalysts during PEMFC *** fast decay has been well understood in close relation to the demetallation at the initial 15-h stability ***,it is still unclear how the remanent active sites evolve after *** this end,the catalyst performance and evolution of a typical fe/N/C active site were herein investigated through postmortem characterizations of the membrane electrode assemblies(MEAs)after different *** is presented that 1 bar pressure and 80℃ temperature are the optimized conditions for fe/N/C ***,the“fast decay”in the initial 15 h is immune to the various operating parameters,while the“slow decay”highly depends on the applied temperature and *** to the X-ray absorption spectra(XAS)analysis and stability test of MEA,the gradual evolution of fe-N coordination to fe-O is found correlated with the“slow decay”and accounts for the catalyst decay after the demetallation process.

关键词： fe/N/C Stability Decay mechanism Metal oxidation PEMFCs

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fe-Zn alloy, a new biodegradable material capable of reducing RoS and inhibiting oxidative stress

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Regenerative Biomaterials 2024年第2期3卷 114-122页

作者： Shuaikang yang Weiqiang Wang Yanan Xu Yonghui Yuan Shengzhi Hao School of Materials Science and Engineering Dalian University of TechnologyDalian 116024PR China Clinical Research Center for Malignant Tumor of Liaoning Province Cancer Hospital of Dalian University of TechnologyShenyang 110042PR China

fe-based biodegradable materials have attracted significant attention due to their exceptional mechanical properties and favorable ***,research on fe-based materials mainly focuses on regulating the degradation ***,excessive release of fe ions during material degrada-tion will induce the generation of reactive oxygen species(ROS),leading to oxidative stress and ***,the con-trol of RoS release and the improvement of biocompatibility for fe-based materials are very *** this study,new fe-Zn alloys were prepared by electrodeposition with the intention of using Zn as an antioxidant to reduce oxidative damage during alloy ***,the impact of three potential degra-dation ions(fe^(2+),fe^(3+),Zn^(2+))from the fe-Zn alloy on human endothelial cell(EC)activity and migration ability was ***,cell adhesion,cell activity,ROs production and DNA damage were assessed at various locations surrounding the ***,the influence of different concentrations of Zn^(2+) in the medium on cell viability and ROS production was *** levels of ROS exhibited evident toxic effects on ECs and promoted DNA *** an antioxidant,Zn?+effectively reduced ROS production around fe and improved the cell viability on its surface at a concentration of 0.04 mmol/*** findings demonstrate that fe-Zn alloy can attenuate the ROS generated from fe degradation therebyenhancingcytocompatibility.

关键词： biodegradable iron fe-Zn alloys reactive oxygen species oxidative stress cytocompatibility

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Efficient removal of tetracycline hydrochloride through novel fe/BiOBr/Bi_(2)WO_(6) photocatalyst prepared by dual-strategy under visible-light irradiation

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Journal of Environmental Sciences 2024年第4期138卷 46-61页

作者： guanlong Yu Kai yang Yi yang Yifu Li Qifang Sun Peiyuan Li Wenming Wang fe.gming Song Tao Ling Xuejun Peng Zhi Yu Shiquan Sun School of Hydraulic and Environmental Engineering Changsha University of Science&TechnologyChangsha 410114China Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province Changsha 410114China Hunan Pilot yanghu Reclaimed Water Co. Ltd.Changsha 410208China China Railway Wuju group the First Engineering Co. Ltd.Changsha 410117China

It is important to investigate whether combining two modification strategies has a synergistic effect on the activity of *** this manuscript,fe-doped BiOBr/Bi_(2)WO_(6) heterojunctions were synthesized by a one-pot solvothermal method,and excellent photocatalytic performance was obtained for the degradation of tetracycline hydrochloride(TCH)in water without the addition of *** experiments and characterization,the synergistic effect between fe ion doping and the BiOBr/Bi_(2)WO_(6) heterojunction was *** fe/BiOBr/Bi_(2)WO_(6) composite photocatalyst had a beneficial void structure,enhanced visible light response,and could inhibit the recombination of photogenerated support well,which improved the photocatalytic *** presented experiments demonstrate that fe/BiOBr/Bi_(2)WO_(6) removes 97% of TCH from aqueous solution,while pure BiOBr and Bi_(2)WO_(6) only remove 56% and 65% of TCH,***,the separation and transfer mechanisms of photoexcited carriers were determined in conjunction with the experimental *** study provides a new direction for the design of efficient photocatalysts through the use of a dual co-modification strategy.

关键词： BiOBr/Bi_(2)WO_(6) fe-doping Dual strategy Tetracycline hydrochloride Photodegradation

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Construction of electron rich fe active sites by feCu alloy anchoring on carbon nitride for photocatalytic nitrogen reduction

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Rare Metals 2024年第4期43卷 1570-1579页

作者： gang Dong Cong Huang fei-yang Chen Xue-Qin Liu Zhen Li Xiao-Li Su Tao Zeng Yun-Xia Chen Yi-Huang Chen yang Wang School of Materials Science and Engineering Jingdezhen Ceramic UniversityJingdezhen333403China Faculty of Materials Science and Chemistry China University of GeosciencesWuhan430074China College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou325035China

given the clean and inexhaustible solar energy from solar light,photocatalytic ammonia synthesis is extremely ***,high electron-hole recombination rates and insufficient active sites severely limited N2 photoreaction ***,we designed and fabricated feCu alloy nanoparticles anchored on carbon nitride nanosheets with excellent photocatalyt ic ammonia synthesis *** a coupler between fe and carbon nitride,Cu promotes the separation of photogenerated charge carriers in carbon nitride under solar light irradiation,and renters the semiconductor a forceful electron donor for the fe active *** accumulated electrons at fe sites furtherly facilitated the adsorption and activation of the molecular ***,the uniform dispersed feCu alloy nanoparticles were on carbon nitride nanosheets enhanced the stability of photocataly tic nitrogen reduction reaction,making the artificial photocataly tic ammonia synthesis more sustainable for *** work highlights that a direct electron transfer channel can be used to regulate the photochemical nitrogen fixation network.

关键词： Photocatalytic N_2 fixation Carbon nitride feCu alloy Active sites Hydrogenation pathway

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Impact of Co^(2+)substitution on structure and magnetic properties of M-type strontium ferrite with different fe/Sr ratios

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Chinese Physics B 2024年第10期33卷 427-433页

作者： yang Sun Ruoshui Liu Huayang gong Baogen Shen School of Rare Earths University of Science and Technology of ChinaHefei 230026China ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341119China Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo 315201China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Ion substitution has significantly improved the performance of ferrite magnets,and cobalt remains a key area of *** on the mechanism of Co^(2+)in strontium ferrite,especially Srfe_(2n-x)Co_(x)O_(19-d)(n=6.1-5.4;x=0.05-0.20)synthesized using the ceramic method,showed that Co^(2+)preferentially enters the lattice as the fe/Sr ratio *** results in a decrease in the lattice constants a and c due to oxygen vacancies and iron ion *** impact of Co substitution on morphology is minor compared to the effect of the fe/Sr *** the fe/Sr ratio decreases and the Co content increases,the saturation magnetization *** magnetic anisotropy field exhibits a nonlinear change,generally increasing with higher fe/Sr ratios and Co *** changes in the performance of permanent magnets are attributed to the absence of fe^(3+)ions at the 12k+2a and 2b sites and the substitution of Co^(2+)at the 2b *** suggests that by adjusting the fe/Sr ratio and appropriate Co substitution,the magnetic anisotropy field of M-type strontium ferrite can be effectively optimized.

关键词： hexaferrite Co substitution Raman spectra magnetic properties

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Advances in depressants for flotation separation of Cu–fe sulfide minerals at low alkalinity:A critical review

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 1-17页

作者： Qicheng fe.g Wenhang yang Maohan Chang Shuming Wen Dianwen Liu guang Han State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China Yunnan Key Laboratory of green Separation and Enrichment of Strategic Mineral Resources Kunming University of Science and TechnologyKunming 650093China

The flotation separation of Cu–fe sulfide minerals at low alkalinity can be achieved using selective *** the flotation system of Cu–fe sulfide minerals,depressants usually preferentially interact with the pyrite surface to render the mineral surface hydrophilic and hinder the adsorption of the *** review summarizes the advances in depressants for the flotation separation of Cu–fe sulfide minerals at low *** advances include use of inorganic depressants (oxidants and sulfur–oxygen compounds),natural polysaccharides (starch,dextrin,konjac glucomannan,and galactomannan),modified polymers (carboxymethyl cellulose,polyacrylamide,lignosulfonate,and tricarboxylate sodium starch),organic acids (polyglutamic acid,sodium humate,tannic acid,pyrogallic acid,salicylic acid,and lactic acid),sodium dimethyl dithiocarbamate,and *** potential application of specific inorganic and organic depressants in the flotation separation of Cu–fe sulfide minerals at low alkalinity is *** advances in the use of organic depressants with respect to the flotation separation of Cu–fe sulfide minerals are comprehensively ***,the depression performances and mechanisms of different types of organic depressants on mineral surfaces are ***,several perspectives on depressants vis-à-vis flotation separation of Cu–fe sulfide minerals at low alkalinity are proposed.

关键词： Cu–fe sulfide minerals flotation separation selective depressants depression mechanism

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