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Facile synthesis of Ni-,Co-,Cu-metal organic frameworks electrocatalyst boosting for hydrogen evolution reaction

Journal of Materials Science & Technology 2021年第13期72卷 172-179页

作者： Man Zhang Di Hu Zhenhao Xu Biying Liu mebrouka boubeche Zuo Chen Yuchen Wang Huixia Luo Kai Yan Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology School of Environmental Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Key Lab of Polymer Composite&Functional Materials School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou510275China

The conductive metal-organic frameworks(MOFs)are suggested as the ideal electrocatalysts for hydrogen evolution reaction(HER)because of the high utilization of metal *** design and facile synthesis of MOFs with large specific surface area,proper metals as center,and tunable chemical components is still full of ***,we report the facile synthesis three types of porous MOFs by regulating metal center using benzene-1,3,5-tricarboxylic acid(H3 BTC)as organic ligand and have successfully synthesized the rhombic octahedral Cu-BTC,rod-shaped Co-BTC and spherical Ni-BTC materials with large specific surface area ranged in 350-500 m^(2)g^(-1).These as-prepared MOFs materials exhibit high performance of HER in 0.5 M H_(2)SO_(4).Ni-BTC material exhibits the lowest overpotential of 53 mV at 10 mA cm-2 and the smallest Tafel slope of 62 mV dec^(-1)than those of Cu-BTC(270 mV,155 mV dec^(-1))and Co-BTC(123 mV,100 mV dec^(-1)),which are much superior to these previously reported MOFs *** addition,the fast catalytic kinetic of Ni-BTC was confirmed by the smaller charge transfer resistance(Rct)value of 0.9Ωand larger electrochemical active surface area(ECSA)of 35.5 cm^(2)than those of Cu-BTC(8.2Ω,22.5 cm^(2))and Co-BTC(1.9Ω,27.7 cm^(2)).Because of the structural advantage and large ECSA,the turnover frequency(TOF)value of Ni-BTC reaches up to 0.041 s-1 at 120 mV overpotential,which is 20.5 and 2.6 times greater than that of Cu-BTC(0.002 s-1)and Co-BTC(0.016 s-1).Besides,these three types of MOFs exhibited excellent durability over 12 *** study unfolds diverse insights into the design and facile synthesis of MOFs for electrochemical energy conversion system.

关键词： Metal-organic frameworks Hydrogen evolution reaction Activity Overpotential Durability

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Extremely strong coupling s-wave superconductivity in the medium-entropy alloy TiHfNbTa

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Science China(Physics,Mechanics & Astronomy) 2023年第7期66卷 127-135页

作者： Lingyong Zeng Xunwu Hu mebrouka boubeche Kuan Li Longfu Li Peifeng Yu Kangwang Wang Chao Zhang Kui Jin Dao-Xin Yao Huixia Luo School of Materials Science and Engineering State Key Laboratory of Optoelectronic Materials and TechnologiesKey Lab of Polymer Composite&Functional MaterialsGuangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSun Yat-Sen UniversityGuangzhou 510275China Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices Center for Neutron Science and TechnologySchool of PhysicsSun Yat-Sen UniversityGuangzhou 510275China Songshan Lake Materials Laboratory University Innovation TownDongguan 523808China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Vacuum Physics School of Physical SciencesUniversity of Chinese Academy of SciencesBeijing 100049China

Here we report a TiHfNbTa bulk medium-entropy alloy(MEA)superconductor crystallized in the body-centered cubic structure with the unit cell parameter a=3.35925?,which is synthesized by an arc melting *** properties of the TiHfNbTa are studied by employing magnetic susceptibility,resistivity,and specific heat *** results show a bulk superconducting transition temperature(Tc)of around 6.75 *** lower and upper critical fields for TiHfNbTa are45.8 m T and 10.46 T,***-principles calculations show that the d electrons of Ti,Hf,Nb,and Ta are the main contribution to the total density of states near the Fermi *** results indicate that the superconductivity is a conventional swave type with extremely strong coupling(△C_(el)/γ_(n)T_(c)=2.88,2△_(0)/k_(B)T_(c)=5.02,and λ_(ep)=2.77).The extremely strong coupling behavior in the s-wave type Ti Hf Nb Ta MEA superconductor is unusual because it generally happens in cuprates,pnictides,and other unconventional superconductors.

关键词： medium-entropy alloy superconductivity s-wave type TiHfNbTa

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Superconductivity and Charge Density Wave in Iodine-Doped CuIr_(2)Te_(4)

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Chinese Physics Letters 2021年第3期38卷 81-88页

作者： mebrouka boubeche Jia Yu Li Chushan Wang Huichao Lingyong Zeng Yiyi He Xiaopeng Wang Wanzhen Su Meng Wang Dao-Xin Yao Zhijun Wang Huixia Luo School of Materials Science and Engineering State Key Laboratory of Optoelectronic Materials and Technologiesand Key Lab of Polymer Composite&Functional MaterialsSun Yat-Sen UniversityGuangzhou 510275China School of Physics Sun Yat-Sen UniversityGuangzhou 510275China Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

We report a systematic investigation on the evolution of the structural and physical properties,including the charge density wave(CDW) and superconductivity of the polycrystalline CuIr_(2)Te_(4-x)Ix for 0.0 ≤x≤ *** diffraction results indicate that both of a and c lattice parameters increase linearly when 0.0 ≤ x ≤ *** resistivity measurements indicate that the CDW is destabilized with slight x but reappears at x≥0.9 with very high ***,the superconducting transition temperature Tc enhances as x increases and reaches a maximum value of around 2.95 K for the optimal composition CuIr_(2)Te_(1.9)I_(0.1) followed by a slight decrease with higher iodine doping *** specific heat jump(ΔC/γTc) for the optimal composition CuIr_(2)Te_(3.9)I_(0.1) is approximately 1.46,which is close to the Bardeen-Cooper-Schrieffer value of 1.43,indicating that it is a bulk *** results of thermodynamic heat capacity measurements under different magnetic fields |Cp(T,H)],magnetization M(T,H) and magneto-transport ρ(T,H) measurements further suggest that CuIr_(2)Te_(4-x)Ix bulks are type-Ⅱ ***,an electronic phase diagram for this CuIr_(2)Te_(4-x)Ix system has been *** present study provides a suitable material platform for further investigation of the interplay of the CDW and superconductivity.

关键词： resistivity magnetization diagram

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Journal of Materials Science & Technology 2023年第32期163卷 158-167页

作者： Jijun Xin Wei Wang Xiao Yang mebrouka boubeche Shanlin Wang Hengcheng Zhang Chuanjun Huang Yong Li Bingkun Lyu Fuzhi Shen Wentao Sun Laifeng Li Songshan Lake Materials Laboratory Dongguan 523808China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Nanchang Hangkong University Jiangxi Key Laboratory of Forming and Joining Technology for Aerospace ComponentsNanchang 330036China

The microstructure and mechanical properties of dissimilar laser beam welded joint between CrMnFeCoNi alloy and 316LN stainless steel was *** results showed that the defect-free dissimilar joint was obtained by laser beam *** ultimate strength of the welded joints can reach∼90%of the base materials at both room and cryogenic *** deformation substructure mainly consisted of planar dislocation,the stacking faults and the dissociation of stacking faults into *** volume fraction of the nanotwins was increasing at cryogenic *** hardness fluctuates greatly in welded joint and the lowest hardness was located at fusion zone near the fusion *** fracture of the welded joint was located at the fusion zone in consistence with the lowest hardness *** is mainly attributed to the coarse grain and stress concentration at this area.

关键词： High entropy alloy Stainless steel Cryogenic temperature Microstructure evolution Mechanical properties

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富空穴CoSi合金无溶剂无碱醇氧化

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Chinese Journal of Catalysis 2023年第5期48卷 175-184页

作者：赵志月蒋志伟黄一哲 mebrouka boubeche Valentina G.Matveeva Hector F.Garces 罗惠霞严凯中山大学环境科学与工程学院广东广州510006 中山大学材料与工程学院光电材料与技术国家重点实验室广东广州510006 特维尔国立技术大学生物技术与化学系俄罗斯布朗大学工程学院美国

醇类化合物选择性氧化为醛、酸和酯在工业应用中是一类重要的化学反应.按照绿色化学的要求,无溶剂、无外加碱源,以分子氧为氧化剂,对醇类氧化反应提出了重要挑战,特别是无溶剂氧化醇制备酯类化学品.因此开发高效催化剂应用于无溶剂醇氧... 详细信息

醇类化合物选择性氧化为醛、酸和酯在工业应用中是一类重要的化学反应.按照绿色化学的要求,无溶剂、无外加碱源,以分子氧为氧化剂,对醇类氧化反应提出了重要挑战,特别是无溶剂氧化醇制备酯类化学品.因此开发高效催化剂应用于无溶剂醇氧化成为研究热点.目前Pd基贵金属催化剂应用于醇的无溶剂氧化已取得一定进展,但贵金属的稀缺性限制了其工业应用.由于碱性环境可以有效促进醇的氧化,但碱性物质的添加可能导致反应体系的二次污染.此外,Co基非贵金属催化剂可以有效无溶剂氧化醇,但稳定性一般.因此,合成高活性高稳定性催化剂用于醇类化合物的无溶剂选择性氧化是重要的科学问题.本文采用电弧熔炼法可控制备半金属CoSi合金(AM-CoSi),在无溶剂无碱条件下将其应用于六种芳香醇的选择性氧化.采用X射线吸收精细结构谱、电子顺磁共振和球差扫描透射电镜对AM-CoSi催化剂进行结构表征,发现其以钴硅合金的形式存在,具有Co空穴和Si空穴,并且以Si空穴为主.反应结果表明,使用AM-CoSi催化剂在220℃可完全转化苯甲醇,并以70%的产率得到苯甲酸苄酯(BBE),使用无缺陷CoSi合金,只得到9.5%的BBE,说明Si空穴存在可以高效的转化苯甲醇并高产率得到BBE.此外,通过调控反应温度,使用AM-CoSi无溶剂氧化六种芳香醇(带有不同吸电子基团和供电子基团)可高选择性得到对应的醛,选择性高达84%以上.中间体反应实验结果表明,AM-CoSi催化剂具有很好的酯化催化活性,苯甲醇首先氧化成苯甲醛,再氧化成苯甲酸,然后苯甲酸与苯甲醇发生酯化反应生成BBE.采用单组分合金成分和无空穴CoSi合金(S-CoSi)进行催化剂对比实验,发现合金结构和空穴有利于苯甲醇的氧化.设计无空穴CoSi合金、Co空穴CoSi合金和Si空穴CoSi合金三种催化剂模型,并利用密度泛函理论计算模拟苯甲醇在这三种模型上的氧化路径,结果表明,CoSi合金结构促进醇的转化,Si空穴有利于BBE的产生.综上,本文将为其他半金属合金催化剂的合成和应用提供了新思路.

关键词：半金属合金醇氧化无溶剂空穴密度泛函理论计算

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