X射线光电光谱表征金属氧化物的酸碱性

本文探讨了氧配位的八面体及四面体的金属配合物中氧原子的价态变化及其酸碱性差异之间的关系。首先利用X射线光电光谱(XPS)分别推导出了氧原子在碱及碱土铝酸盐、铬酸盐、高铁酸盐、钼酸盐及钨酸盐中的价态,随后对氧原子的价态及氧化物的酸碱性质进行了比较。研究结果表明,氧原子的价态在这两种配位构型的化合物中没有显著的差别,其酸碱性的不同在于四面体配位的金属化合物中O2p态在非成键和成键的电子密度中高价带的分裂。

X射线光电子光谱法研究壳聚糖吸附镉(Ⅱ)的机理

用X射线光电子光谱法测定了壳聚糖和壳聚糖 Cd2 +络合物表面C、O及N原子的结合能及组成 ,研究了壳聚糖与镉离子的作用机理 ,氮原子的化学位移表明氨基是吸附活性基团 ,由化学分析和XPS得到参与吸附的N/Cd值为1 .6,存在物理吸附和化学吸附 。

Applications of in-situ wide spectral range infrared absorption spectroscopy for CO oxidation over Pd/SiO_(2) and Cu/SiO_(2) catalysts

Infrared(IR)absorption spectroscopy has been widely used for dynamic characterization of catalysts and mechanism of catalytic reactions.However,due to the strong infrared absorption of heterogeneous catalysts(mainly oxides,or supported metal and metal oxides,etc.)below 1200 cm^(-1),and the intensity of regular infrared light source rapidly decays at low-wavenumber range,most in-situ infrared spectroscopy studies are limited to the detection of surface adsorbates in the range of 4000-900 cm^(-1).The change of catalytically active component itself(M-O,M-M bond,etc.,1200-50 cm^(-1))during the reaction is hard to be tracked under reaction conditions by in-situ IR.In this work,a home-made in-situ IR reactor was designed and a sample preparing method was developed.With such progresses,the changes of reactants,products,surface adsorbates,and catalysts themselves can be measured under the same reaction conditions with a spectral range of 4000-400 cm^(-1),providing a new opportunity for in-situ characterization of heterogeneous catalysis.CO oxidation on Pd/SiO_(2) and Cu/SiO_(2) catalysts were taken as examples,since both the two catalytic systems were extensively used commercially,and moreover reduction and oxidation of palladium and copper occur during the examined reaction conditions.The characteristic bands of Pd^(2+)-O(670,608 cm^(-1)),Cu^(+)-O(635 cm^(-1))and Cu^(2+)-O(595,535 cm^(-1))were observed by IR,and the changes during CO oxidation reaction were successfully monitored by IR.The oxidation/reduction of palladium and copper were also confirmed by ex-situ XPS.Moreover,Pd^(0) in Pd/SiO_(2) and Cu^(+)in Cu/SiO_(2) were found as the thermal dynamically stable phases under the examined conditions for CO oxidation.

Construction of a macromolecular structural model of Chinese lignite and analysis of its low-temperature oxidation behavior

The aim of this paper is to analyze the change in the active structure of lignite during the process of lowtemperature oxidation by constructing a molecular structure model for lignite. Using quantum computation combined with experimental results of proximate analysis, ultimate analysis, Fourier transform infrared spectroscopy(FTIR) and X-ray photoelectron spectroscopy(XPS), a structural model for the large molecular structure was constructed. By analyzing the bond lengths in the model molecule, the evolution law for the active structure of lignite was predicted for the process of low-temperature oxidation. In low-temperature oxidation,alkanes and hydroxyls are the primary active structures observed in lignite, though ether may also react. These active functional groups react with oxygen to release heat, thereby speeding up the reaction between coal and oxygen. Finally, the content of various functional groups in the process of lignite low-temperature oxidation was analyzed by infrared analysis, and the accuracy of the model was verified.

Surface XPS-investigations of tobacco leaves treated with low-temperature plasma

The tobacco leaves were treated with low-temperature plasma in Ar, N2, O2, and air atmospheres at different powers (60―130 W). The surface-elemental components, their relative contents, and the functional groups of the surface components of the tobacco leaves were determined using XPS (X-ray photoelectron spectroscopy). The ex- perimental results showed that the percentage of the elements C, N, and O had changed considerably and a large number of polar functional groups containing oxygen atoms were incorporated into the components on the tobacco surfaces. The measurements of the surface contact angle showed that the surface contact angle of the modified tobacco leaves was 0 degree, whereas it was 110 degrees before the plasma treatment. These results indicate that the wettability of the modified tobacco leaves improved dramatically. This work may be significant for future researches on the surface modification of the tobacco leaves.

Silica-gel Supported V Complexes： Preparation, Characterization and Catalytic Oxidative Desulfunzation

In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG n-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG 2.0-[VVO2-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG 2.0-[VVO2-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 °C, time was 60 min, the O/S was 3:1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.

Characterization of Pyrolytic Lignin Extracted from Bio-oil

Bio-oil is a new liquid fuel produced by fast pyrolysis,which is a promising technology to convert bio-mass into liquid. Pyrolytic lignin extracted from bio-oil,a fine powder,contributes to the instability of bio-oil. The paper presents the structural features of three kinds of pyrolytic lignin extracted from bio-oil with different methods(WIF,HMM,and LMM) . The pyrolytic lignin samples are characterized by Fourier transform infrared spectrometer(FTIR) and X-ray photoelectron spectroscopy(XPS) . FTIR data indicate that the three pyrolytic lignin samples have similar functional groups,while the absorption intensity is different,and show characteristic vibra-tions of typical lignocellulosic material groups O H(3340-3380 cm-1) ,C H(2912-2929 cm-1) and C O(1652-1725 cm-1) . Comparison in the region(3340-3380 cm-1) indicates that WIF has more O H stretch groups than HMM and LMM. The carbon spectra are fitted to four peaks:C1,C C or C H,BE 283.5 eV;C2,C OR or C OH,BE 284.5-285.8 eV;C3,C O or HO C OR,BE 286.10-287.10 eV;C4,O C O,BE 287.5-287.7 eV. The absence of C1,C C or C H indicates the dominant polymerization structure of aro-matic carbon in pyrolytic lignin samples. For HMM and WIF,C2a and C2b can not be separated,so there is no free hydroxyl group in the samples. The oxygen peaks are also fitted to four peaks:O1,OH,BE = 530.3 eV;O2,RC O,BE 531.45-531.72 eV;O3,O C O,BE = 532.73-533.74 eV;O4,H2O,BE 535 eV. The absence of O1 and O4 indicates that little hydroxyl groups and adsorbed water are present in the samples.

Catalytic Performance of Graphite Oxide Supported Au Nanoparticles in Aerobic Oxidation of Benzyl Alcohol： Support Effect

Various Au/GO catalysts were prepared by depositing Au nanoparticles on thermally- and chemically-treated graphite oxide （GO） supports using a sol-immobilization method. The surface chemistry and structure of GO supports were characterized by a series of analytical techniques including X-ray photoelectron spectroscopy, temperature-programmed desorption and Raman spectroscopy. The results show that thermal and chemical treatments have large influence on the presence of surface oxygenated groups and the crystalline structure of GO supports. A strong support effect was observed on the catalytic activity of Au/GO catalysts in the liquid phase aerobic oxidation of benzyl alcohol. Compared to the amount and the type of surface oxygen functional groups, the ordered structure of GO supports may play a more important role in determining the catalytic performance of Au/GO catalysts.

Probing Co/Si interface behaviour by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM)

In this work, we investigate the Co-Si reaction, the Co growth mode at room temperature, diffusion be- haviour as well as morphology evolution during annealing on both H-terminated and clean Si(001) and Si(111) sur- faces. From in-situ X-ray photoelectron spectroscopy (XPS) investigation, “Co-Si” reaction appears to occur on both H-terminated and clean surfaces at room temperature (RT) and the silicide crystallinity is improved upon annealing. Co growth mode on H-terminated Si surfaces occurs in a pseudo layer-by-layer manner while small close-packed is- land growth mode is observed on the clean Si surface. Upon annealing at different temperatures, Co atom concentra- tion decreases versus annealing time, which in part is attributed to Co atoms inward diffusion. The diffusion behav- iour on both types of surfaces demonstrates a similar trend. Morphology study using ex-situ atomic force microscopy (AFM) shows that the islands formed on Si(001) surface after annealing at 700 °C are elongated with growth direc- tions alternate between the two perpendicular [ 110 ] and [110] directions. Triangular islands are observed on Si (111) surface.

Geometric and Electronic Structures of Pyrazine Molecule Chemisorbed on Si(100) Surface by XPS and NEXAFS Spectroscopy

The geometric and electronic structures of several possible adsorption configurations of the pyrazine(C4H4N2)molecule covalently attached to Si(100)surface,which is of vital importance in fabricating functional nano-devices,have been investigated using X-ray spectroscopies.The Carbon K-shell(1s)X-ray photoelectron spectroscopy(XPS)and near-edge X-ray absorption fine structure(NEXAFS)spectroscopy of predicted adsorbed structures have been simulated by density functional theory with cluster model calculations.Both XPS and NEXAFS spectra demonstrate the structural dependence on different adsorption configurations.In contrast to the XPS spectra,it is found that the NEXAFS spectra exhibiting conspicuous dependence on the structures of all the studied pyrazine/Si(100)systems can be well utilized for structural identification.In addition,according to the classification of carbon atoms,the spectral components of carbon atoms in different chemical environments have been investigated in the NEXAFS spectra as well.

Hard X-ray Photoelectron Spectroscopy Study of Electron Spectral Structure beyond the Known Signal Electron Peak

HAXPES （hard X-ray photoelectron spectroscopy） is a powerful emerging instrument in surface analysis. It extended the photoelectron energy range up to 15,000 eV and opened the possibility to study much thicker films, buried layers and bulk electronic properties. In order to study these features, data for the electron IMFP （inelastic mean free path） at these energies is needed. To date, only calculated IMFP are available at energies above 5,000 eV and therefore experimental validation of these calculations are essential. In this paper, a new approach for using the HAXPES spectra is presented. This approach, treats the attenuated part of the electron spectrum as a whole to calculating the average electron energy loss. This average electron energy loss is the result of inelastic collisions in the material and hence, carry with it information about the electron transport poses. Carbon layers with thicknesses between 20 and 75 nanometer deposited over copper substrate were used to test this approach at the Spanish beam-line （Spline） in the ESRF （European synchrotron radiation facility）. The measured results showed good agreement with the predictions of the multiple inelastic scattering theory. In addition, an algorithm for the experimental evaluation of electron IMFP, using the measured energy loss, is proposed.

Low-Temperature Plasma Induced Grafting of 2-Methacryloyloxyethyl Phosphorylcholine onto Poly(tetrafluoroethylene) Films

Modification of poly(tetrafluoroethylene)(PTFE) films with 2-methacryloyloxyethyl phosphorylcholine(MPC) was performed by low-temperature plasma treatment and grafting polymerization.Surface properties of PTFE were characterized by attenuated total reflectance Fourier transform infrared(ATR-FTIR) spectra,X-ray photoelectron spectroscopy(XPS) ,and static contact angle.The results show that MPC has been grafted onto PTFE film surface successfully.Contact angle for the modified PTFE films in the water decreased from 108°to 58.25°,while surface energy increased from 17.52 mN/m to 45.47 mN/m.The effects of plasma treatment time,monomer concentration and grafting time on degree of grafting were determined.In the meanwhile,blood compatibility of the PTFE films was studied by checking thrombogenic time of blood plasma.

Continuous Flow Reactor for Hydroxylation of Benzene to Phenol by Hydrogen Peroxide

The direct hydroxylation of benzene to phenol catalyzed by activated carbon-supported Fe （Fe/AC） in acetonitrile using H2O2 as the oxidant was studied in a continuous flow reactor. Results showed that the continuous operation could obtain high phenol yield of 28.1%, coupled with the turnover frequency of 3 h^-1, and high selectivity of 98% under mild condition. The catalyst was characterized by N2 adsorption/desorption, Boehm titration, X-ray photoelectron spectra, and Fourier transform infrared spectroscopy. It was observed that iron may interact with the carboxyl group forming iron-carboxylate like species, which act as the active phase. The apparent activation energy obtained by fitting an Arrhenius model to the experimental data was 13.4 kJ/mol. The reaction order was calculated to be about i, 0.2 for benzene and 0.7 for H202.

ZnO、PbO和SiO_2纳米复合物的制备与结构表征

采用溶胶 -凝胶法制备了ZnO SiO2 、PbO SiO2 和ZnO PbO SiO2 复合物 ;通过TEM分析发现其均为纳米颗粒 ,平均粒径分别为 4 5nm ,10nm和 5 0nm ;通过比表面及孔径分布测定发现ZnO SiO2 的比表面积最大 ,达715 5m2 g ,平均孔径最小且分布很集中 ;PbO SiO2 的比表面积最小而平均孔径最大且分布也很集中 ;ZnO PbO SiO2的比表面和平均孔径介于其中 ;通过XPS分析发现ZnO、PbO和SiO2 间存在着相互作用。

“黑色”非晶形三价铁羟基氧化物及其对有害物质的吸附(英文)

利用硝酸铁与氨水之间的水解反应,生成了一种新的“黑色”非晶形三价铁羟基氧化物(FeOOH)该物质在室温下稳定,有较高的硬度,其比表面积约为300m2/g,零电荷点(PZC)在pH7～8之间根据Mssbauer谱的鉴定,它具有四方纤铁矿(β-FeOOH)的结构特征FeOOH和它与各溶质的表面配合物的X射线光电光谱结果表明,FeOOH与Pb、Zn和CrO2-4之间的反应是物理吸附,而与PO3-4和AsO3-4之间的反应是化学吸附3个阴离子及2个阳离子的吸附等温式结果表明,该三价铁羟基氧化物的吸附能力比常见的铁羟基氧化物强3倍磷酸盐与砷酸盐之间的竞争反应结果表明,磷酸盐与FeOOH的反应比砷酸盐强烈。

助溶剂对铝合金表面硅烷化预处理的影响

为了了解3-缩水甘油醚丙基三甲氧基硅烷(γ-GPTMS)溶液中助溶剂对水解的γ-GPTMS在铝合金表面的沉积特性的影响,用X射线光电子衍射(XPS)测定了不同助溶剂含量,不同γ-GPTMS浓度的溶液沉积在铝合金表面的硅含量,同时用反射吸收红外光谱(RAIRS)对铝合金表面膜层进行了表征,结果表明,助溶剂对γ-GPTMS在铝合金表面沉积有显著影晌,γ-GPTMS的纯水溶液在铝合金表面所形成硅烷化膜层的硅元素量最高,沉积量随溶液中γ-GPTMS浓度的增加而增加。另外,膜层与氧化的铝合金表面之间形成铝硅氧烷(Al-O-Si)共价键,而且γ-GPTMS分子中的烷氧乙基分布在膜层的外表面,具有较大的反应活性。

Study on Effect of Compounding Sulfurized Isobutylene with Thisester

Oxygen is introduced into the sulfurized isobutylene by compounding the sulfurized isobutylene with thioester,This paper studies the synergistic effet of commingling the sulfurized isobutylene with thioester during testing in the four-ball maching and the hihg-speed Timken maching ,Tests in the four-ball machine and the high-speed Timken machine have revealed an improvement in EP perforance of sulfurized isobutylene in admixture with thiosester The interfacial tension test and electrochenical analysis of anodic polariztion have discovered increase of adsorptive force of the additive package on metal surface following compounding sulfrized isobutylene with thioester,The XPS and AES analyees indicate to the formation of FeS,Fe2O3 and FeSO4,on the metal surface.The sulfurized film formed by the additive package on the metal surface is thicker than that formed by simple sulfurized isobutylene.

Electric characteristics of Nd_2O_3 doped BaTiO_3 ceramics

Nd2O3 doped BaTiO3ceramics（the additive content was respectively 0.001, 0.002, 0.003, 0.005, 0.01 molar ratio）were prepared by Sol-Gel method to study their dielectric characteristics and electric conductivities through X-ray photoelectron spectrum （XPS）. The results showed that the dielectric characteristics of Nd2O3 doped BaTiO3 ceramics were improved by doping. When Nd2O3 content was 0.003 mol, the results were even better, the dielectric constant was increased, the dielectric loss was decreased, the Curie-temperature （Tc） was 110 ℃, and the frequency characteristic was also good. The resistivity of Nd2O3 doped BaTiO3 ceramics was lower than that of pure BaTiO3 ceramics, when Nd2O3 content was 0.001 mol,the resistivity was （2.364×）108 Ω·m, the smallest. The grain resistance of Nd2O3 doped BaTiO3 ceramics exhibited NTC effect, but the grain boundary resistance showed PTC effect, and the grain boundary resistance was larger than that of the grain resistance, so the PTC effect originated from the grain boundary. The analysis of the element binding energy through X-ray photoelectron spectrum were indicated that the quantivalence of Ba2+and Ti4+in Nd2O3 doped BaTiO3 ceramics was variable, and resulted in the improvement of the conductibility of BaTiO3 ceramics.

Synthesis and Antimicrobial Activity of Boron-doped Titania Nano-materials

Antibacterial activity of boron-doped TiO2(B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2(anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti O B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans(ATCC10231), Gram-negative Escherichia coli(ATCC25922) and Gram-positive Staphylococcus aureus(ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.

Characterization and recycling of nickel- and chromium-contained pickling sludge generated in production of stainless steel

Pickling sludge generated during the neutralization of pickling wastewater with calcium hydroxide in stainless steel pickling process was characterized using X-ray fluorescence spectrometry, X-ray diffractometry, scanning electron microscopy, thermogravimetry and differential scanning calorimetry, etc. The major compositions of pickling sludge are CaF2, CaSO4, Me（OH）, （M： Fe, Cr, Ni）, and the content of CaF2 is high in the sludge. The melting point of pickling sludge is about 1350℃ and the viscosity is about 0.14 Pa.s at 1450 ℃, which are comparatively lower than those of normal refining slag. After heat treatment, the contents of sulfur and fluorine in the pickling sludge were reduced, confirming the thermal decomposition of sulfate in the sludge. Fluorine in the sludge is reduced by the gaseous SiF4 and A1F3 generated through the reactions of CaF2 with SiO2 and Al2O3. The preliminary results from the reduction test indicate that the sulfur content in the steel is not affected by the presence of sulfur in the sludge. The recovery of nickel is about 40%, and the chromium content changes marginally due to the protective atmosphere under the reduction condition of chromic oxide. The pickling sludge is a potential auxiliary material for the production of stainless steel.