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Ammonium Impacts on Vibrations of Hydroxyl and Lattice of Phengite at High Temperature and High Pressure

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Journal of Earth Science 2021年第5期32卷 1278-1286页

作者： Weihua Huang Yan Yang zeming qi Wendi Liu Zhongping Wang Yan Liu Qunke Xia School of Earth Sciences Zhejiang UniversityHangzhou 310027China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Department of Physics University of Science and Technology of ChinaHefei 230026China

Dehydration in hydrous phases of the downgoing slab controls water release processes in subduction zones. Interplay between volatiles in hydrous minerals has complicated the previous knowledge of their dehydration. Phengite is an essential mineral carrying both hydrogen and nitrogen to the deep Earth. To further understand the link between nitrogen and dehydration process of phengite at an atomic level, we here carry out high temperature and high pressure vibrational spectroscopic investigations on hydroxyl and lattice of ammonium-bearing and ammonium-free phengites. The results show that heating to 800 oC hardly influences hydroxyl bonding strength, whereas pressure induces strengthening of hydrogen bonding until 10 GPa. Moreover, hydrogen transits between the sites with increasing temperature and pressure. The lattice modes soften with increasing temperature and stiffen under compression. Ammonium has no effect on hydroxyl bonding strength, but hinders hydrogen transition at high temperatures and high pressures. Ammonium does not influence the lattice at high pressures either, but delays softening of the lattice at high temperatures. These data unveil behavior of hydroxyl and lattice in phengite at high temperature and high pressure, and also evaluate ammonium impacts, shedding new lights on dehydration processes of phengite during subduction.

关键词： hydroxyl lattice ammonium phengite high temperature high pressure

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Sulfur-vacancy-tunable interlayer magnetic coupling in centimeter-scale M0S2 bilayer

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Nano Research 2022年第2期15卷 881-888页

作者： Hengli Duan Guinan Li Hao Tan Chao Wang qian Li Chuanchuan Liu Yuewei Yin Xiaoguang Li zeming qi Wensheng Yan National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Hefei National Laboratory for Physical Sciences at the Microscale Department of Physicsand CAS Key Laboratory of Strongly-coupled Quantum Matter PhysicsUniversity of Science and Technology of ChinaHefei 230026China

Endowing bilayer transition-metal dichalcogenides(TMDs)with tunable magnetism is significant to investigate the coupling of multiple electron degrees of freedom(DOFs).However,effectively inducing and tuning the magnetic interaction of bilayer TMDs are still ***,we report a strategy to tune the interlayer exchange interaction of centimeter-scale MoS2 bilayer with substitutional doping of Co ion,by introducing sulfur vacancy(V_(s))to modulate the interlayer electronic *** strategy could transform the interlayer exchange interaction from antiferromagnetism(AFM)to ferromagnetism(FM),as revealed by the magnetic *** characterizations and theoretical calculations indicate that the enhanced magnetization is mainly because the hybridization of Co 3d band and Vs-induced impurity band alters the forms of interlayer orbital hybridizations between the partial Co atoms in upper and lower layers,and also enhances the intralayer *** work paves the way for tuning the interlayer exchange interaction with defects and could be extended to other two-dimensional(2D)magnetic materials.

关键词： interlayer exchange interaction 2D magnetic materials S-vacancy interlayer coupling large-area growth

A Unique Ru-N_(4)-P Coordinated Structure Synergistically Waking Up the Nonmetal P Active Site for Hydrogen Production

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Research 2020年第1期2020卷 944-955页

作者： Chuanqiang Wu Shiqing Ding Daobin Liu Dongdong Li Shuangming Chen Huijuan Wang zeming qi Binghui Ge Li Song National Synchrotron Radiation Laboratory CAS Center for Excellence in NanoscienceUniversity of Science and Technology of ChinaHefeiAnhui 230029China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China Institute of Amorphous Matter Science School of Materials Science and EngineeringHefei University of TechnologyHefeiAnhui 230009China Experimental Center of Engineering and Material Science University of Science and Technology of ChinaHefei 230026China

Numerous experiments have demonstrated that the metal atom is the active center of monoatomic catalysts for hydrogen evolution reaction(HER),while the active sites of nonmetal doped atoms are often *** combining theoretical prediction and experimental verification,we designed a unique ternary Ru-N_(4)-P coordination structure constructed by monodispersed Ru atoms supported on N,P dual-doped graphene for highly efficient hydrogen evolution in acid *** density functional theory calculations indicate that the charge polarization will lead to the most charge accumulation at P atoms,which results in a distinct nonmetallic P active sites with the moderate H∗adsorption ***,these P atoms mainly supply highly efficient catalytic sites with ultrasmall absorption energy of 0.007 ***,the Ru-N_(4)-P demonstrated outstanding HER performance not only in an acidic condition but also in alkaline ***,the performance of Ru-NPC catalyst at high current is even superior to the commercial Pt/C catalysts,whether in acidic or alkaline *** in situ synchrotron radiation infrared spectra demonstrate that a P-H_(ads) intermediate is continually emerging on the Ru-NPC catalyst,actively proving the nonmetallic P catalytically active site in HER that is very different with previously reported metallic sites.

关键词： solution alkaline catalyst

Classical spin liquid state in a rhombic lattice metal-organic framework

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Nano Research 2024年第4期17卷 3407-3412页

作者： Sihua Feng Chao Wang Jiyin Zhao Xuguang Liu Chaocheng Liu zeming qi Lei Chen Huijuan Wang Minghui Fan Hengli Duan Wensheng Yan National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China Experimental Center of Engineering and Material Science University of Science and Technology of ChinaHefei 230026China

Discovering more and new geometrically frustrated systems remains an active point of inquiry in fundamental physics for the existence of unusual states of ***,we report spin-liquid-like behavior in a two-dimensional(2D)rhombic lattice Fe-metal-organic framework(Fe-MOF)with frustrated *** Fe-MOF exhibits a high frustration factor f=|θCW|/TN≥315,and its long-range magnetic order is suppressed down to 180 *** theoretical calculations demonstrate strong antiferromagnetic coupling between adjacent Fe3+ions,indicating the potential of a classical spin-liquid-like ***,a T-linear heat capacity parameter,γ,originating from electronic contributions and with magnetic field independence up to 8 T,can be observed in the specific heat capacity measurements at low-temperature,providing further proof for the spin-liquid-like *** work highlights the potential of MOF materials in geometrically frustrated systems,and will promote the research of exotic quantum physics phenomena.

关键词： spin-liquid-like state two-dimensional metal-organic framework(2D MOF) rhombic lattice ultralow temperature(ULT)measurements spin-frustrated

Single atom accelerates ammonia photosynthesis

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Science China Chemistry 2018年第9期61卷 1187-1196页

作者： Pengcheng Huang Wei Liu Zhihai He Chong Xiao Tao Yao Youming Zou Chengming Wang zeming qi Wei Tong Bicai Pan Shiqiang Wei Yi Xie Hefet National Laboratory for Physical Sciences at the Microscale CAS Center for Excellence in Nanoscience iCHEM University of Science and Technology of China Hefei 230026 China National Synchrotron Radiation Laboratory University of Science and Technology of China. Hefei 230029 China High Magnetic Field Laboratory Chinese Academy of Sciences Hefei 230031 China

Atomically dispersed metal has gained much attention because of the new opportunities they offer in catalysis. However, it is still crucial to understand the mechanism of single-atom catalysis at molecular level for expanding them to other more difficult catalytic reactions, such as ammonia synthesis from nitrogen. In fact, developing ammonia synthesis under ambient conditions to overcome the high energy consumption in well-established Haber-Bosch process has fascinated scientists for many ***, we demonstrate that single Cu atom yields facile valence-electron isolation from the conjugated π electron cloud of p-CN. Electron spin resonance measurements reveal that these isolated valence electrons can be easily excited to generate free electrons under photo-illumination, thus inducing high efficient photo-induced ammonia synthesis under ambient *** NH_3 producing rate of copper modified carbon nitride(Cu-CN) reached 186 μmol g^(-1) h^(-1) under visible light irradiation with the quantum efficiency achieved 1.01% at 420 nm monochromatic light. This finding surely offers a model to open up a new vista for the ammonia synthesis at gentle conditions. The introduction of single atom to isolate the valence electron also represents a new paradigm for many other photocatalytic reactions, since the most photoinduced processes have been successfully exploited sharing the same origin.

关键词： single atom photocatalytic ammonia synthesis

Quantitative research on higher order harmonics in metrology beamline

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Frontiers of Electrical and Electronic Engineering in China 2008年第1期3卷 105-109页

作者： Hongjun ZHOU Jinjin ZHENG Tonglin HUO Guobin ZHANG zeming qi Pengfei ZHONG National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China

The synchrotron radiation spectra of the spherical grating monochromator(SGM)working in the soft X-ray and VUV region are often contaminated by significant amounts of higher order *** cannot be suppressed completely by suitable *** order contributions in the spectral radiation standard and metrology beamline were researched using transmission grating(made in-house)and IRD AXUV100G(USA)photodiode *** exit beam was dispersed with the transmission grating behind the exit slit of the monochromator,and the contributions of the different orders were *** higher order distributions were quantitatively determined for three gratings with line densities of 1800,600 and 200 l/*** results show that in wavelengths between 5 nm and 15 nm the contributions of the higher orders to the detector signal are restricted to less than 7%even without the use of *** wavelength regions between 5 nm and 34 nm,the contributions of the higher orders to the detector signal are less than 14%with proper Al,Si_(3)N_(4) and Zr filters,and after being modified by quantum efficiency of the detector,the higher order contributions are restricted to less than 6.5%.The study also shows that higher orders are almost totally suppressed by MgF_(2) filter when the wavelength ranges between 115–140 nm.

关键词： spectral radiation standard higher order harmonics spectral radiation metrology

Working-in-tandem mechanism of multi-dopants in enhancing electrocatalytic nitrogen reduction reaction performance of carbon- based materials

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Nano Research 2021年第9期14卷 3234-3239页

作者： Wenqing Zhang Keke Mao Jingxiang Low Hengjie Liu Yanan Bo Jun Ma qiaoxi Liu Yawen Jiang Jiuzhong Yang Yang Pan zeming qi Ran Long Li Song Yujie Xiong Hefei National Laboratory for Physical Sciences at the Microscale Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)School of Chemistry and Materials Scienceand National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230041China School of Energy and Environment Science Anhui University of TechnologyMaanshan 243032China Institute of Energy Hefei Comprehensive National Science CenterHefei 230031China

Developing carbon-based electrocatalysts with excellent N2 adsorption and activation capability holds the key to achieve highly efficient nitrogen reduction reaction(NRR)for reaching its practical ***,we report a highly active electrocatalyst--metal-free pyrrolic-N dominated N,S co-doped carbon(pyrr-NSC)for *** on theoretical and experimental results,it is confirmed that the N and S-dopants practice a working-in-tandem mechanism on pyrr-NSC,where the N-dopants are utilized to create electropositive C sites for enhancing N2 adsorption and the S-dopants are employed to induce electron backdonation for facilitating N2 *** synergistic effect of the pyrrolic-N and S-dopants can also suppress the irritating hydrogen evolution reaction,further boosting the NRR *** work gives an indication that the combination of two different dopants on electrocatalyst can enhance NRR performance by working in the two tandem steps-the adsorption and activation of N2 molecules,providing a new strategy for NRR electrocatalyst design.

关键词： N2 reduction reaction metal-free catalyst heteroatoms doping asymmetric charge distribution electrocatalysis

(CaO)_(20.68)(MgO)_(1.32)(SiO_2)_4S_2∶Eu^(2+),Dy^(3+)红光材料的制备与发光特性

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中国稀土学报 2007年第1期25卷 51-54页

作者：刘淼施朝淑戚泽明刘波中国科学技术大学物理系安徽合肥230026 中国科学技术大学国家同步辐射实验室安徽合肥230029

研究了峰值波长651nm的红色发光材料(CaO)20.68(MgO)1.32(SiO2)4S2∶Eu2+,Dy3+的制备及发光特性。通过XRD分析表明硫气氛中合成的材料为具有硫成分的硅酸盐相。红光发射带为硫元素进入晶格后在发光中心周围形成了类似长余辉材料CaS∶Eu2... 详细信息

研究了峰值波长651nm的红色发光材料(CaO)20.68(MgO)1.32(SiO2)4S2∶Eu2+,Dy3+的制备及发光特性。通过XRD分析表明硫气氛中合成的材料为具有硫成分的硅酸盐相。红光发射带为硫元素进入晶格后在发光中心周围形成了类似长余辉材料CaS∶Eu2+,Cl-的局域结构。这也使材料具有了硫化物长余辉材料的发射光谱特征和硅酸盐材料高化学稳定性和高亮度的优点。热释光测量揭示它可能是一种潜在的红色长余辉材料。

关键词：红光发射硅酸盐硫化物长余辉稀土

Temperature Dependence of Red Long Afterglow from Y_2O_2S∶Eu, Ti, Mg

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Journal of Rare Earths 2006年第1期24卷 24-24页

作者： Zhou Dongfang Shi Chaoshu qi zeming Liu Miao Tao Ye Liu Bo Chen Yonghu Department of Physics University of Science and Technology of China Hefei 230026 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 China Institute of High Energy Physics Chinese Academy of Sciences Beijing China

At low temperature, some long-lasting phosphors could not work well in practical applications. So it is necessary to investigate the temperature dependence of the phosphors. The ***, Ti, Mg microcrystalline samples were prepared by solid state reaction method. Phosphors were sintered at 1150 ℃ for 20 min in air, putting in and taking out both at high temperature. The emission spectra and the afterglow spectra as well as the thermoluminescence curve were measured for Y2O2S：Eu,

关键词： long after glow Y2O2S:Eu, Ti, Mg rare earths