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Synthesis and Crystal Structure of Na_2TiO_3

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Chinese Journal of Structural Chemistry 2008年第5期27卷 553-557页

作者：毛少瑜任骁侠周朝辉 state key laboratory for physical Chemistry of solid surfaces Department of Chemistry Xiamen University

The crystal structure of a sodium titanium oxide Na2TiO3 obtained by high temperature solid state reaction method was determined from single-crystal X-ray diffraction study. The compound crystallizes in the monoclinic system, space group C2/c, Mr = 141.88, a = 9.885（1）, b = 6.4133（8）, c = 5.5048（7） A, β = 115.50（3）°, V = 314.99（7） A^3, Z = 4, Dc = 2.992 g/cm^3, 2 = 0.71073A,μ = 27.80 cm^-1, F（000） = 272, T= 295 K, R = 0.0189 and wR = 0.0512 for 30 variables and 370 contributing unique reflections. The three-dimensional structure in Na2TiO3 is constructed by the TiO（1）4O（2） and NAO（1）3O（2）2 groups. The titanium atoms are grouped in the form of trigonal bipyramid and arranged along the c axis by sharing the edges. The structure is compared with other structures of related A2BO3 compounds.

关键词： synthesis crystal structure X-ray diffraction

Molecular behavior of the aptamer HJ24 self-assembled on highly oriented pyrolytic graphite(HOPG)

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Science China Chemistry 2015年第12期58卷 1858-1865页

作者： Xueqin Zhao Yishun Huang Chaoyong James Yang Bingwei Mao College of Life Sciences Zhejiang Sci-Tech University state key laboratory of physical Chemistry of the solid surfaces

Nucleic acid sensing analysis has been widely applied to the fields of food quality control, environmental monitoring, and medical diagnosis. A key step in developing effective DNA-based electrochemical biosensors is to obtain a biorecognition layer on the biosensor, which can be influenced by many factors. Hence, we constructed a series of HJ24 layers on highly oriented pyrolytic graphite to investigate the relation between the configuration of the adsorbed probe HJ24 and the redox property using atomic force microscopy and voltammetry. We used HJ24 for its diagnostic value as it specifically recognizes the SH2 domain-containing phosphatase, a critical contributor in many important signaling pathways. The results demonstrated that increasing K ions induced G-quartet oxidation peak occurrence/increase([K+]?400 mmol/L), and also resulted in the formation of more compact single strand sheets([K+]?300 mmol/L). Moreover, transitions of molecule configurations and redox currents of G-quartets were observed at low concentration [K+]=12 mmol/L, which may indicate the appearance of new configurations under this condition. Besides, by analyzing atomic force microscopy(AFM) images, it was found that the different adsorbed configurations are correlated with the HJ24 concentration, the basal configuration, and the linker group on the HJ24 sequence. This information may be useful for understanding the adsorption process of HJ24 as well as for the further development of practical applications for HJ24 films on DNA electrochemical sensors, and may ultimately help improve the diagnosis and treatment of patients with SHP2-related diseases.

关键词： self-assembly G-quadruplex DNA SHP2 Atomic force microscopy HOPG

CVD synthesis of nitrogen-doped graphene using urea

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Science China(Physics,Mechanics & Astronomy) 2015年第10期58卷 94-99页

作者： ZHANG CanKun LIN WeiYi ZHAO ZhiJuan ZHUANG PingPing ZHAN LinJie ZHOU YingHui CAI WeiWei Department of Physics Laboratory of Nanoscale Condense Matter Physics and State Key Laboratory of Physical Chemistry of Solid SurfacesXiamen University

This work provides an effective low-cost synthesis and in-depth mechanistic study of high quality large-area nitrogen-doped graphene(NG) films. These films were synthesized using urea as nitrogen source and methane as carbon source, and were characterized by scanning electron microscopy(SEM), Raman spectroscopy and X-ray photoelectron spectroscopy(XPS). The N doping level was determined to be 3.72 at.%, and N atoms were suggested to mainly incorporated in a pyrrolic N configuration. All distinct Raman peaks display a shift due to the nitrogen-doping and compressive strain. The increase in urea concentration broadens the D and 2D peak's Full Width at Half Maximum(FWHM), due to the decrease of mean free path of phonons. The N-doped graphene exhibited an n-type doping behavior with a considerably high carrier mobility of about 74.1 cm2/(V s), confirmed by electrical transport measurements.

关键词： nitrogen-doped graphene chemical vapor deposition Raman spectroscopy X-ray photoemission spectroscopy

Effect of glutathione on in vivo biodistribution and clearance of surface-modified small Pd nanosheets

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Science China Chemistry 2015年第11期58卷 1753-1758页

作者： Yizhuan Huang Xiaolan Chen Saige Shi Mei Chen Shaoheng Tang Shiguang Mo Jingping Wei Nanfeng Zheng state key laboratory for physical Chemistry of solid surfaces Department of Chemistry College of Chemistry and Chemical EngineeringXiamen University

Plasmonic Pd nanosheets have been emerging as promising materials for application in near-infrared(NIR) photothermal therapy(PTT) of cancer. However, animal in mice studies indicated that the original synthesized poly(vinylpyrrolidone)(PVP)-protected small Pd nanosheets(Pd-PVP) and some further surface-modified small Pd nanosheets such as Pd-PEG(SH) easily accumulated in reticuloendothelial system(RES) organs(liver, spleen, etc.) and were difficult to be cleared from these organs quickly. In the work, we surprisingly found that glutathione(GSH) could promote the clearance of surface-modified small Pd nanosheets(e.g. Pd-PVP, Pd-PEG(SH) and Pd-GSH) from the RES organs efficiently. The effects of GSH on the biodistribution and clearance of different surface-modified Pd nanosheets were investigated. Our results indicated that these surface-modified Pd nanosheets with or without GSH added caused no morbidity at target primary organs, and GSH can promote the clearance of different surface-modified Pd nanosheets in the order of Pd-PVP≈Pd-PEG(SH)>Pd-GSH. This study suggests that glutathione could be an attractive reagent for promoting nanomaterials eliminated from the reticuloendothelial systems(RES).

关键词： noble metal nanomaterials glutathione biodistribution renal clearance

A new solvent suppression method via radiation damping effect

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Chinese Physics B 2011年第11期20卷 525-529页

作者：崔晓红彭凌张振敏蔡淑惠陈忠 Department of Electronic Science Fujian Key Laboratory of Plasma and Magnetic ResonanceState Key Laboratory of Physical Chemistry of Solid SurfacesXiamen University

Radiation damping effects induced by the dominated solvent in a solution sample can be applied to suppress the solvent signal. The precession pathway and rate back to equilibrium state between solute and solvent spins are different under radiation damping. In this paper, a series of pulse sequences using radiation damping were designed for the solvent suppression in nuclear magnetic resonance （NMR） spectroscopy. Compared to the WATERGATE method, the solute signals adjacent to the solvent would not be influenced by using the radiation damping method. The one-dimensional （1D） ^1H NMR, two-dimensional （2D） gCOSY, and J-resolved experimental results show the practicability of solvent suppression via radiation damping effects in 1D and 2D NMR spectroscopy.

关键词： nuclear magnetic resonance solvent suppression radiation damping

Observation of intermolecular double-quantum coherence signal dips in nuclear magnetic resonance

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Chinese Physics B 2011年第10期20卷 190-197页

作者：沈桂平蔡聪波蔡淑惠陈忠 Department of Electronic Science and Communications Engineering Fujian Key Laboratory of Plasma and Magnetic Resonance State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen University

The correlated spectroscopy revamped by asymmetric Z-gradient echo detection （CRAZED） sequence is modified to investigate intermolecular double-quantum coherence nuclear magnetic resonance signal dips in highly polarized spin systems. It is found that the occurrence of intermolecular double-quantum coherence signal dips is related to sample geometry, field inhomogeneity and dipolar correlation distance. If the field inhomogeneity is refocused, the signal dip occurs at a fixed position whenever the dipolar correlation distance approaches the sample dimension. However, the position is shifted when the field inhomogeneity exists. Experiments and simulations are performed to validate our theoretic analysis. These signal features may offer a unique way to investigate porous structures and may find applications in biomedicine and material science.

关键词： nuclear magnetic resonance distant dipolar field intermolecular double-quantum coher-ence signal dip

Advances in microwave absorbing materials with broad-bandwidth response

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Nano Research 2023年第8期16卷 11054-11083页

作者： Susu Bao Meixi Zhang Zhiyuan Jiang Zhaoxiong Xie Lansun Zheng state key laboratory for physical Chemistry of solid surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China

Microwave absorbing materials(MAMs)are playing an increasingly essential role in the development of wireless communications,high-power electronic devices,and advanced target detection *** with a broad-bandwidth response are particularly important in the area of communication security,radiation prevention,electronic reliability,and military *** considerable progress has been made in the design and preparation of MAMs with a broad-bandwidth response,a number of challenges still remain,and the structure–function relationship of MAMs is still far from being completely ***,the advances in the design and research of MAMs with a broad-bandwidth response are *** main strategies for expanding the effective absorption bandwidth of MAMs are comprehensively summarized considering three perspectives:the chemical combination strategy,morphological control strategy,and macrostructure control *** important results as well as design principles and absorption mechanisms are highlighted.A coherent explanation detailing the influence of the chemical composition and structure of various materials on the microwave absorption properties of MAMs is *** main challenges,new opportunities,and future perspectives in this promising field are also presented.

关键词： microwave absorbing materials broad-bandwidth response magnetic-dielectric synergy morphology control macrostructure control

Copper/cuprous sulfide electrode: preparation and performance

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Science China Chemistry 2015年第6期58卷 1039-1043页

作者： Lina Xiao Ding Yuan Pei Li Li Huang Bing-Wei Mao Dongping Zhan state key laboratory for physical Chemistry of solid surfaces Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University

Cuprous sulfide （Cu2S） is a direct band-gap p-type semiconductor with excellent ionic/electronic hybrid conductivity. Alt- hough Cu/Cu2S/sulfide or polysulfide system is adopted as counter electrode of quantum-dots-sensitized solar cells （QDSSC）, the electrode process is seldom reported. Here, the electrochemical growth of Cu2S film on a copper （Cu） surface, the redox behaviors of sulfide and polysulfide, and the all-in-solid charge-transfer properties of Cu2S film are investigated. It is clarified that the copper electrode simultaneously undergoes an activated process, a membrane growth process, and a redox phase transformation process. The solid charge-transfer capability of CuzS is quantified with a high exchange-current density of 2.27 A/cm2, which elucidates that the Cu/CuzS electrode is a qualified material for counter electrodes of QDSSC. These results aid understanding of the physicochemical mechanism of QDSSC with a polysulfide electrolyte and Cu/Cu2S counter electrode.

关键词： quantum dots sensitized solar cells counter electrode cuprous sulfide film growth

Ab initio VB Studies of the Ground and Low-lying Excited states of BeH and BH

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Chinese Journal of Chemistry 2003年第8期21卷 1005-1010页

作者：廖新丽莫亦荣吴玮张乾二 Department of Chemistry State Key Laboratory for Physical Chemistry of Solid Surfaces Center for Theoretical Chemistry Xiamen University

A scheme has been proposed to classify valence bond (VB) wave functions for the calculations of ground and excited states, according to the symmetry properties of one electron orbitals which are involved in the construction of VB wave functions. This scheme is illustrated by the examples of BeH and BH. Ab initio VB computations of these two test molecules in combination with the present classification scheme give reliable results. For example, calculation results show that the state C 2Σ +of BeH is stable, with the bonding energy 0 87 eV and bond length 0 238 nm, which are in good agreement with those obtained by Gerratt et al . The bonding features of ground and low lying excited states of BeH and BH are discussed.

关键词： valence bond theory excited state BeH BH