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Tuning the performance of nitrogen reduction reaction by balancing the reactivity of N_(2) and the desorption of NH_(3)

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Nano Research 2021年第11期14卷 4093-4099页

作者： Lijuan Niu Dandan Wang Kang Xu Weichang Hao Li An Zhenhui Kang Zaicheng Sun Beijing Key Laboratory for Green Catalysis and Separation Center of Excellence for Environmental Safety and Biological EffectsFaculty of Environment and LifeBeijing University of TechnologyBeijing100124China Key Laboratory of functional materials Physics and Chemistry of the Ministry of Education College of PhysicsJilin Normal UniversitySiping136000China Department of Physics Key Laboratory of Micro-Nano MeasurementManipulation and PhysicsMinistry of EducationBeihang UniversityBeijing100191China Jiangsu Key Laboratory for Carbon-based functional materials and Devices Institute of Functional Nano and Soft Materials(FUNSOM)Soochow UniversitySuzhou215123China Macao Institute of materials Science and Engineering Macao University of Science and TechnologyTaipa999078Macao SARChina

Electrochemical reduction of nitrogen to ammonia under mild conditions provides an intriguing approach for energy conversion. A grand challenge for electrochemical nitrogen reduction reaction (NRR) is to design a superior electrocatalyst to obtain high performance including high catalytic activity and selectivity. In the NRR process, the three most important steps are nitrogen adsorption, nitrogen activation, and ammonia desorption. We take MoS_(2) as the research object and obtain catalysts with different electronic densities of states through the doping of Fe and V, respectively. Using a combination of experiments and theoretical calculations, it is demonstrated that V-doped MoS_(2) (MoS_(2)-V) shows better nitrogen adsorption and activation, while Fe-doped MoS_(2) (MoS_(2)-Fe) obtains the highest ammonia yield in experiments (20.11 µg·h^(−1)·mg^(−1)cat.) due to its easier desorption of ammonia. Therefore, an appropriate balance between nitrogen adsorption, nitrogen activation, and ammonia desorption should be achieved to obtain highly efficient NRR electrocatalysts.

关键词： nitrogen reduction reaction MoS_(2) electrocatalyst nitrogen-fixing

Kaolin-based geopolymers with various NaOH concentrations

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International Journal of Minerals,Metallurgy and materials 2013年第3期20卷 313-322页

作者： C.Y. Heah H. Kamarudin A.M. Mustafa Al Bakri M. Bnhussain M. Luqman I. Khairul Nizar C.M. Ruzaidi Y.M. Liew center of excellence Geopolymer and Green Technology (CEGeoGTech) School of Materials Engineering Universiti Malaysia Perlis (UniMAP) King Abdulaziz City Science and Technology

Kaolin geopolymers were produced by the alkali-activation of kaolin with an activator solution （a mixture of NaOH and sodium silicate solutions）. The NaOH solution was prepared at a concentration of 6-14 mol/L and was mixed with the sodium silicate solution at a Na2SiO3/NaOH mass ratio of 0.24 to prepare an activator solution. The kaolin-to-activator solution mass ratio used was 0.80. This paper aimed to analyze the effect of NaOH concentration on the compressive strength of kaolin geopolymers at 80℃ for 1, 2, and 3 d. Kaolin geopolymers were stable in water, and strength results showed that the kaolin binder had adequate compressive strength with 12 mol/L of NaOH concentration. When the NaOH concentration increased, the SiO2/Na20 decreased. The increased Na20 content enhanced the dissolution of kaolin as shown in X-ray diffraction （XRD） and Fourier transform infrared spectroscopy （FTIR） analyses. However, excess in this content was not beneficial for the strength development of kaolin geopolymers. In addition, there was the formation of more geopolymeric gel in 12 mol/L samples. The XRD pattern of the samples showed a higher amorphous content and a more geopolymer bonding existed as proved by FTIR analysis.

关键词： geopolymers kaolin compressive strength sodium hydroxide

In situ phase transitional polymeric vaccines for improved immunotherapy

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National Science Review 2022年第2期9卷 99-108页

作者： Jie Wang Yi Wang Shenglin Qiao Muhetaerjiang Mamuti Hongwei An Hao Wang CAS center for excellence in Nanoscience CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and Technology (NCNST) center of materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

Cancer vaccines have exhibited immense potential in cancer *** activating the host’s immune system,vaccines stimulate extensive functional T cells to eliminate ***,the therapeutic efficacy of cancer vaccines is limited by their inferior lymph node delivery and inadequate uptake of dendritic ***,we propose an in situ phase transitional strategy on vaccine manufacturing to maximally enhance lymph node drainage while ensuring adequate dendritic cell *** phase transitional vaccines,with dynamic size modulation property,retain a small size(24.4±3.1 nm) during lymph node draining then transform into larger particles(483.0±41.6 nm) on-site by external signal *** show that this strategy induced rapid and robust immune response in a mouse melanoma tumor ***,a stronger humoral immune response was observed in mice when immunized with MHC-Ⅱ restricted antigen,which demonstrated that lymph node-targeted cancer vaccine delivery could be effe ctively manipulated through dynamic size modulation.

关键词： nanomedicine lymph node delivery cancer vaccine size modulation dendritic cell

Epitaxial growth of antimony nanofilms on HOPG and thermal desorption to control the film thickness

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Chinese Physics B 2020年第9期29卷 164-171页

作者： Shuya Xing Le Lei Haoyu Dong Jianfeng Guo Feiyue Cao Shangzhi Gu Sabir Hussain Fei Pang Wei Ji Rui Xu Zhihai Cheng Beijing Key Laboratory of Optoelectronic functional materials&Micro-nano Devices Department of PhysicsRenmin University of ChinaBeijing 100872China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100039China

Group-V elemental nanofilms were predicted to exhibit interesting physical properties such as nontrivial topological properties due to their strong spin-orbit coupling,the quantum confinement,and surface *** was reported that the ultrathin Sb nanofilms can undergo a series of topological transitions as a function of the film thickness h:from a topological semimetal(h>7.8 nm)to a topological insulator(7.8 nm>h>2.7 nm),then a quantum spin Hall(QSH)phase(2.7 nm>h>1.0 nm)and a topological trivial semiconductor(h<1.0 nm).Here,we report a comprehensive investigation on the epitaxial growth of Sb nanofilms on highly oriented pyrolytic graphite(HOPG)substrate and the controllable thermal desorption to achieve their specific *** morphology,thickness,atomic structure,and thermal-strain effect of the Sb nanofilms were characterized by a combination study of scanning electron microscopy(SEM),atomic force microscopy(AFM),and scanning tunneling microscopy(STM).The realization of Sb nanofilms with specific thickness paves the way for the further exploring their thickness-dependent topological phase transitions and exotic physical properties.

关键词： epitaxial growth antimony films scanning tunneling microscope(STM) thermal desorption

An A-D-A′-D-A type unfused nonfullerene acceptor for organic solar cells with approaching 14%efficiency

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Science China Chemistry 2021年第2期64卷 228-231页

作者： Xingzheng Liu Yanan Wei Xin Zhang Linqing Qin Zhixiang Wei Hui Huang College of materials Science and Opto-Electronic Technology Center of Materials Science and Optoelectronics EngineeringCAS Center for Excellence in Topological Quantum ComputationCAS Key Laboratory of Vacuum PhysicUniversity of Chinese Academy of SciencesBeijing 100049China CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China

In recent years,power conversion efficiency(PCE)of organic solar cells(OSCs)has made significant improvement.A large number of studies were reported to achieve high PCEs through exploring new active layer materials,especially the high efficiency fused ring acceptors(FRAs).Compared with FRAs,another type of so-called unfused-ring acceptors(UFAs),possessing some advantages such as simple synthesis and low cost,have attracted a lot of ***,a new UFA BTzO-4F,incorporating with a benzotriazole moiety and S···O intramolecular noncovalent interactions,has been successfully *** photovoltaic device based on PBDB-T:BTzO-4F achieved a record PCE of 13.8%for UFAs,which indicates that introducing the benzotriazole moiety is an effective strategy for high quality ***,these findings of this work demonstrate the great potential of UFAs for high performance OSCs.

关键词： organic solar cells unfused nonfullerene acceptor benzotriazole moiety

Realizing Plain Optimization of the Thermoelectric Properties in BiCuSeO Oxide via Self-Substitution-Induced Lattice Dislocations

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Research 2023年第4期2023卷 755-764页

作者： Rui Xu Zhiwei Chen Qizhu Li Xiaoyu Yang Han Wan Mengruizhe Kong Wei Bai Nengyuan Zhu Ruohan Wang Jiming Song Zhou Li Chong Xiao Binghui Ge Information materials and Intelligent Sensing Laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information Technology and School of Materials Science and EngineeringAnhui UniversityHefei 230601China Institute of Energy Hefei Comprehensive National Science CenterHefei 230031China School of materials Science and Engineering Tongji UniversityShanghai 201804China Hefei National Laboratory for Physical Sciences at the Microscale CAS Center for Excellence in NanoscienceUniversity of Science and Technology of ChinaHefei 230026China

Seeking new strategies to tune the intrinsic defect and optimize the thermoelectric performance via no or less use of external doped elements(i.e.,plain optimization)is an important method to realize the sustainable development of thermoelectric ***,creating dislocation defects in oxide systems is quite challenging because the rigid and stiff ionic/covalent bonds can hardly tolerate the large strain energy associated with ***,taking BiCuSe_(O) oxide as an example,the present work reports a successful construction of dense lattice dislocations in BiCuSe_(O) by self-doping of Se at the O site(i.e.,Se_(O) self-substitution),and achieves plain optimization of the thermoelectric properties with only external Pb *** to the self-substitution-induced large lattice distortion and the potential reinforcement effect by Pb doping,high-density(about 3.0×10^(14 )m^(−2))dislocations form in the grains,which enhances the scattering strength of mid-frequency phonon and results in a substantial low lattice thermal conductivity of 0.38 W m^(−1) K^(−1) at 823 K in Pb-doped BiCuSe_(O).Meanwhile,PbBi doping and Cu vacancy markedly improve the electrical conductivity while maintaining a competitively high Seebeck coefficient,thereby contributing to a highest power factor of 942μW m^(−1) K^(−2).Finally,a remarkably enhanced zT value of 1.32 is obtained at 823 K in Bi_(0.94)Pb_(0.06)Cu_(0.97)Se_(1.05)O_(0.95) with almost compositional *** high-density dislocation structure reported in this work will also provide a good inspiration for the design and construction of dislocations in other oxide systems.

关键词： plain doping dislocation

Atomistic understanding of capacity loss in LiNiO_(2)for high-nickel Li-ion batteries:First-principles study

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Chinese Physics B 2024年第5期33卷 625-629页

作者：彭率陈丽娟何长春杨小宝 School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510000China center of excellence for Advanced materials Dongguan 523808China

Combining the first-principles calculations and structural enumeration with recognition,the delithiation process of LiNiO_(2)is investigated,where various supercell shapes are considered in order to obtain the formation energy of Li_(x)NiO_(2).Meanwhile,the voltage profile is simulated and the ordered phases of lithium vacancies corresponding to concentrations of 1/4,2/5,3/7,1/2,2/3,3/4,5/6,and 6/7 are *** understand the capacity decay in the experiment during the charge/discharge cycles,deoxygenation and Li/Ni antisite defects are calculated,revealing that the chains of oxygen vacancies will be energetically *** can be inferred that in the absence of oxygen atom in high delithiate state,the diffusion of Ni atoms is facilitated and the formation of Li/Ni antisite is induced.

关键词： Li-ion battery ground state formation energy oxygen vacancy Li/Ni antisite

PtAu bimetallic nanocatalyst for selective hydrogenation of alkenes over aryl halides

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Nano Research 2019年第7期12卷 1659-1662页

作者： Le Guo Junjie Mao Shuangxi Guo Qi Zhang Shuangfei Cai Wei He School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety Center of Materials Science and Optoelectronics EngineeringCAS center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyUniversity of Chinese Academy of SciencesBeijing 100190China center of Single-Atom Clusters and Nanomaterials (CAN)Key Laboratory of Functional Molecular SolidsMinistry of EducationAnhui Key Laboratory of Molecule-Based MaterialsCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China

Herein,we present a new strategy that for the first time achieved chemo- and enantio-selective hydrogenation of alkenes over *** to the success is that instead of using external poisons,we use the composition of the bimetallic nanocrystal catalysts to control chemoselectivity (hydrogenation of C=C bonds without cleavage of Ar-X bonds).We further show that this system combined with surface modifying chiral ligands can control the ***,after synthesizing and screening a series of easily accessible MxAuy (M = Pd,Pt;x,y= 1,3,5) bimetallic nanocrystals (9-10 nm) supported on activated carbon,we identified that PtiAui/C is a recyclable and generally applicable catalyst for the chemoselective hydrogenation of alkenes without cleaving aryl halogen ***,cinchonidine modified Pt,Aui/C is shown to be capable of enantioselective hydrogenation,as illustrated by the rapid and enantio-enriched synthesis of RIP1 inhibitor analogue 7-Br-O-Necl.

关键词： hydrogenation chemoselectivity enantioselectivity PtAu bimetallic

Host-guest supramolecular interaction behavior at the interface between anode and electrolyte for long life Zn anode

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Journal of Energy Chemistry 2022年第6期31卷 237-243,I0007页

作者： Kai Wu Fanghua Ning Jin Yi Xiaoyu Liu Jiaqian Qin Yuyu Liu Jiujun Zhang Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghai 200444China center of excellence in Responsive Wearable materials Metallurgy and Materials Science Research InstituteChulalongkorn UniversityBangkok 10330Thailand

The hydrogen evolution reaction (HER) and dendrite growth associated with Zn anode have become the main bottlenecks for the further development of zinc ion batteries (ZIBs).In this work,the electrochemical activity of H_(3)O^(+) is inhibited by the supramolecular host–guest complex composed of H_(3)O^(+) as guest and 18-crown-6 as *** even Zn plating is induced by the host–guest complex electrostatic shielding layer on Zn anode,as detected by in-situ optical *** lamellar Zn is plated which profits from the improved Zn plating *** functional theory (DFT) calculation presents the stable structure of *** less produced H_(2) content is monitored online by a mass spectrometer during Zn plating/stripping,which indicates HER can be hampered by the host–guest ***,the ZIBs with long life and high Coulombic efficiency are achieved via introducing *** proposed host–guest supramolecular interaction is expected to facilitate the furthermore development of Zn batteries.

关键词： H_(2)evolution Zn plating behavior Host-guest supramolecular interaction Dendrite free zinc ion batteries