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Platinum monolayers stabilized on dealloyed AuCu core-shell nanoparticles for improved activity and stability on methanol oxidation reaction

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Chinese Chemical Letters 2020年第3期31卷 836-840页

作者： Weihua Guo Xiaozhang Yao Lingyi Peng Bingqing Lin Yongqiang Kang Lin Gan Division of Energy and Environment Graduate School at ShenzhenTsinghua UniversityShenzhen 518055China

Deposition of platinum(Pt)monolayers(PtML)on Au substrate represents a robust strategy to maximally utilize the Pt atoms and meanwhile achieve high catalytic activity towards methanol oxidation reaction for direct methanol fuel cells owing to a substrate-induced tensile strain effect.However,recent studies showed that Pt(ML)on Au substrate are far from perfect smooth monoatomic layer,but actually exhibited three-dimensional nanoclusters.Moreover,the Pt(ML)suffered from severe structural instability and thus activity degradation during long-term electrocatalysis.To regulate the growth of Pt(ML)Au surface and also to improve its structural stability,we exploit dealloyed AuCu core-shell nanoparticles as a new substrate for depositing Pt(ML).By using high-resolution scanning transmission electron microscopy and energy dispersive X-ray elemental mapping combined with electrochemical characte rizations,we reveal that the dealloyed AuCu core-shell nanoparticles can effectively promote the deposition of Pt(ML)closer to a smooth monolayer structure,thus leading to a higher utilization efficiency of Pt and higher intrinsic activity towards methanol oxidation compared to those on pure Au nanoparticles.Moreover,the Pt(ML)deposited on the AuCu core-shell NPs showed substa ntially enhanced stability compared to those on pure Au NPs during long-term electrocatalysis over several hours,during which segregation of Cu to the Au/Pt interface was revealed and suggested to play an important role in stabilizing the Pt(ML)catalysts.

关键词： Platinum monolayers Methanol oxidation reaction Core-Shell nanoparticles Dealloying Stability

Chemically engineered dendrite growth of uniform monolayers MoS_(2) for enhanced photoluminescence[Invited]

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Chinese Optics Letters 2022年第1期20卷 94-100页

作者：苏欢欢张会珍吴文静王翔王广厚周林 National Laboratory of Solid State Microstructures School of PhysicsCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210093China Department of Electrical Engineering The Pennsylvania State UniversityUniversity ParkPennsylvania 16802USA

Large area and uniform monolayer MoS_(2)is of great importance for optoelectronic devices but is commonly suffering from rather weak photoluminescence.Here,by engineering the concentration profiles of gaseous chemicals through extra trace amounts of water,we demonstrate the uniform dendrite-type growth of monolayer MoS_(2)unraveled by spatially resolved fluorescence spectroscopy,which exhibits macroscopic monolayer flakes [up to centimeter scale] with photoluminescence intensity of orders of magnitude higher than conventional chemical vapor deposition monolayer MoS_(2).Both spectroscopic evidence and theoretical models reveal that the fast-fractal dendrite growth can be ascribed to the extra introduced water sources that generate sufficient aqueous gas around the S-poor regions nearby the central-axis zone,leading to highly efficient Mo sources transport,accelerated S atom corrosion nearby grain edges,and/or defect sites,as well as enhanced photoemission intensity.Our results may provide new insight for high throughput fabrication of MoS_(2)monolayers with high yield photoluminescence efficiency.

关键词： spectroscopy monolayers MoS_(2) photoluminescence enhancement dendrite chemical vapor deposition

Erratum to:Influence of metal support in-plane symmetry on the corrugation of hexagonal boron nitride and graphene monolayers

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Nano Research 2019年第5期12卷 1217-1218页

作者： Antonio J.Martinez-Galera Jose M.Gomez-Rodriguez Departamento de Fisica de la Materia Condensada Universidad Autonoma de MadridMadrid E-28049Spain Condensed Matter Physics Center(IFIMAC) Universidad Autonoma de MadridMadrid E-28049Spain Instituto Nicolas Cabrera Universidad Autonoma de MadridMadrid E-28049Spain

The writings of the text on the last line,left column on the 4^th page and the text on lines 8^th,10^th,11^th and 16^th in the 4^th paragraph,left column and on lines from 1st to 8^th in the 1st paragraph,right column on the 5^th page,and the text on line 4^th in the 1^st paragraph,left column on the 9^th page,and Fig.3 and its caption on the 5^th page in the original version of this article were unfortunately incorrect.

关键词： corrugation hexagonal boron nitride graphene monolayers

Structural, mechanical, and electronic properties of 25 kinds of Ⅲ–Ⅴbinary monolayers: A computational study with first-principles calculation

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Chinese Physics B 2019年第8期28卷 258-269页

作者：刘雪飞罗子江周勋魏节敏王一郭祥吕兵丁召 College of Big Data and Information Engineering Guizhou UniversityKey Laboratory of Micro-Nano-Electronics of Guizhou ProvinceGuiyang 550025China Semiconductor Power Device Reliability Engineering Center of Ministry of Education Guiyang 550025China College of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550025China College of Information Guizhou Finance and Economics UniversityGuiyang 550025China Guizhou Institute of Technology Guiyang 550002China

Using first-principle calculations,we investigate the mechanical,structural,and electronic properties and formation energy of 25 kinds ofⅢ-Ⅴ binary monolayers in detail.A relative radius of the binary compound according to the atomic number in the periodic table is defined,and based on the definition,the 25 kinds ofⅢ-Ⅴ binary compounds are exactly located at a symmetric position in a symmetric matrix.The mechanical properties and band gaps are found to be very dependent on relative radius,while the effective mass of holes and electrons are found to be less dependent.A linear function between Young’s modulus and formation energy is fitted with a linear relation in this paper.The change regularity of physical properties of B-Ⅴ(Ⅴ=P,As,Sb,Bi)andⅢ-N(Ⅲ=Al,Ga,In,Tl)are found to be very different from those of otherⅢ-Ⅴ binary compounds.

关键词： density functional theory Ⅲ-Ⅴbinary monolayers band structure mechanical properties

Synthesis of MoX2 (X =Se or S) monolayers with high-concentration 1T'phase on 4H/fcc-Au nanorods for hydrogen evolution

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Nano Research 2019年第6期12卷 1301-1305页

作者： Zhengqing Liu Xiao Zhang Yue Gong Qipeng Lu Zhicheng Zhang Hongfei Cheng Qinglang Ma Junze Chen Meiting Zhao Bo Chen Ye Chen Xue-Jun Wu Pengfei Yin Lin Gu Yaping Du Hua Zhang School of Materials Science and Engineering & National Institute for Advanced Materials Nankai UniversityTianjin 300350China Center for Programmable Materials School of Materials Science and EngineeringNanyang Technological University50 Nanyang AvenueSingapore 639798Singapore Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Collaborative Innovation Center of Quantum Matter Beijing 100190China

Controlled synthesis of transition metal dichalcogenide (TMD) monolayers with unusual crystal phases has attracted increasing attention due to their promising applications in electrocatalysis.However,the facile and large-scale preparation of TMD monolayers with high-concentration unusual crystal phase still remains a challenge.Herein,we report the synthesis of MoX2 (X =Se or S) monolayers with high-concentration semimetallic 1T'phase by using the 4H/face-centered cubic (fcc)-Au nanorod as template to form the 4H/fcc-Au@MoX2 nanocomposite.The concentrations of 1T'phase in the prepared MoSe2 and MoS2 monolayers are up to 86% and 81%,respectively.As a proof-of-concept application,the obtained Au@MoS2 nanocomposite is used for the electrocatalytic hydrogen evolution reaction (HER) in acid medium,exhibiting excellent performance with a low overpotential of 178 mV at the current density of 10 mNcm^2,a small Tafel slope of 43.3 mV/dec,and excellent HER stability.This work paves a way for direct synthesis of TMD monolayers with high-concentration of unusual crystal phase for the electrocatalytic application.

关键词： MoS2 monolayers semimetallic 1T'phase 4H/face-centered cubic (fcc)-Au nanorods hydrogen evolution

Study of physisorption of volatile anesthetics on phos-pholipid monolayers using a highly sensitive quartz crystal microbalance (HS-QCM)

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Journal of Biophysical Chemistry 2011年第2期2卷 68-74页

作者： Yasushi Yamamoto Zameer Shervani Takatsugu Shimoaki Daisuke Yoshida Takashi Yokoyama Tadayoshi Yoshida Keijiro Taga Hiroshi Kamaya Issaku Ueda Department of Life and Materials Engineering Nagoya Institute of Technology Nagoya Japan Dpartment of Materials Science and Engineering Faculty of Engineering Iwate University Ueda Japan

We have investigated the interactions between phospholipid monolayers and volatile anest-hatics. Two monolayers (dihexadecyl phosphate (DHP) and dipalmitoyl phosphatidyl choline (DPPC) and two anesthetics (halothane and enflurane) were used to observe these interac-tions using a highly sensitive quartz crystal microbalance (HS-QCM). The concentration of each anesthetic in aqueous solution was kept at 4 mM. The frequency of QCM showed no change when halothane was added to the DHP monolayer, however, it responded and de-creased when interaction occurred with DPPC monolayer. In case of enflurane addition the frequency decreased in both the monolayers of DHP and DPPC. The frequency change followed the following order of monolayer-anesthetic interactions: DHP-halothane monolayers i.e. the physisorption not only depends on the anesthetic structure, the type of anesthetic hydrate formed, but also the hydrophilic polar group structure of the monolayer or the monolayer/water interface had an important role in physisorption.

关键词： Physisorption Phospholipid monolayers Quartz Crystal Microbalance (QCM) Anesthetic Hydrate Monolayer-Water Interface

Oligo(ethylene glycol)-terminated monolayers on silicon surfaces and their nanopatterning with a conductive atomic force microscope

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Science China Chemistry 2010年第1期53卷 36-44页

作者： QIN GuoTing & CAI ChengZhi Department of Chemistry,University of Houston,Houston,Texas 77204,USA Department of Chemistry University of Houston Houston USA

Functionalization of silicon substrate surfaces with a stable monolayer for resisting non-specific adsorption of proteins has attracted great interest,since it is directly relevant to the development of miniature,silicon-based biosensors and implantable microdevices,such as silicon-neuron interfaces.This brief review summarizes our contribution to the development of robust monolayers grown by surface hydrosilylation on atomically flat,hydrogen-terminated silicon surfaces.The review also outlines our strategy and progress on the fabrication of single molecule patterns on such monolayer platforms.

关键词： protein-resistant monolayers surface hydrosilylation conductive atomic force microscope nanopatterning

Thermodynamic behavior of D-sphingosine/cholesterol monolayers and the topography observed by AFM

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Science China Chemistry 2009年第2期52卷 219-225页

作者： HAO ChangChun SUN RunGuang ZHANG Jing CHANG YiGuang NIU ChunLing College of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062China College of Food Engineering and Nutritional Science Shaanxi Normal UniversityXi’an 710062China

Lipid rafts are of a dynamic microdomain structure found in recent years,enriched in sphingolipids,cholesterol and particular proteins.The change of structure and function of lipid rafts could result in many diseases.In this work,the monolayer behavior of mixed systems of D-sphingosine with choles-terol was investigated in terms of the mean surface area per molecule(Am),excess molecular area(Aex),surface excess Gibbs energy(Gex),interaction parameter(ω),activity coefficients(1 and 2) as well as elasticity(Cs1) of formed films.The deposited Langmuir-Blodgett(LB) monolayers were inves-tigated with atomic force microscopy(AFM).Thermodynamic analysis indicates Aex and Gex in the binary systems with negative deviations from the ideal behavior,suggesting attractive interaction be-tween molecules.The stability,elasticity and activity coefficients show a marked dependence on the mole faction of D-sphingosine.The results of observation by AFM show that the single D-sphingosine molecular film took on small granule structure.When mixing the D-sphingosine and cholesterol at dif-ferent ratios,the mixed films transform from the chains structure to larger slice and net coexisting structure with the increasing of the cholesterol content.In the end,pure cholesterol forms more ag-gregated structure.AFM experiments effectively support the above findings and interpretation.

关键词： monolayers excess Gibbs energy activity coefficients elastic modulus atomic force microscopy

Electrochemical behavior of a series of azobenzene self-assembled monolayers on gold

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Chinese Science Bulletin 1997年第4期42卷 304-307页

作者： Wang, YQ Yu, HZ Cai, SM Liu, ZF BEIJING UNIV CTR INTELLIGENT MAT RESBEIJING 100871PEOPLES R CHINA

THE self-assembled monolayers (SAMs) emerged in the last decade as one of the most convenient and useful methods of preparing molecularly tailored interfaces with controlled spatial and geometric constraints, and have been examined widely from both fundamental and applied perspectives. Recently, SAMs of both unfunctionalized and redox-attached alkanethiols

关键词： self-assembled monolayers azobenzene electron transfer ion transfer.