AFM and XPS Study on the Surface and Interface States of CuPc and SiO_2 Films

A CuPc/SiO2 sample is fabricated. Its morphology is characterized by atomic force microscopy, and the electron states are investigated by X-ray photoelectron spectroscopy. In order to investigate these spectra in detail, all of these spectra are normalized to the height of the most intense peak,and each component is fitted with a single Gaussian function. Analysis shows that the O element has great bearing on the electron states and that SiO2 layers produced by spurting technology are better than those produced by oxidation technology.

Influence of oxygen partial pressure on properties of N-doped ZnO films deposited by magnetron sputtering

N-doped ZnO films were radio frequency(RF)sputtered on glass substrates and studied as a function of oxygen partial pressure(OPP)ranging from 3.0×10-4 to 9.5×10-3 Pa.X-ray diffraction patters confirmed the polycrystalline nature of the deposited films.The crystalline structure is influenced by the variation of OPP.Atomic force microscopy analysis confirmed the agglomeration of the neighboring spherical grains with a sharp increase of root mean square(RMS)roughness when the OPP is increased above 1.4×10-3 Pa.X-ray photoelectron spectroscopy analysis revealed that the incorporation of N content into the film is decreased with the increase of OPP,noticeably N 1s XPS peaks are hardly identified at 9.5×10-3 Pa.The average visible transmittance(380-700 nm) is increased with the increase of OPP(from～17%to 70%),and the optical absorption edge shifts towards the shorter wavelength.The films deposited with low OPP(≤3.0×10-4 Pa)show n-type conductivity and those deposited with high OPP(≥9.0×10-4 Pa)are highly resistive(>105Ω·cm)

Adsorption of cadmium ions from aqueous solutions by activated carbon with oxygen-containing functional groups

The adsorption of aqueous cadmium ions(Cd(Ⅱ)) have been investigated for modified activated carbon(AC-T)with oxygen-containing functional groups.The oxygen-containing groups of AC-T play an important role in Cd(Ⅱ) ion adsorption onto AC-T.The modified activated carbon is characterized by scanning electron microscopy,Fourier transform infrared spectroscopy(FT-IR) and X-ray photoelectron spectroscopy(XPS).The results of batch experiments indicate that the maximal adsorption could be achieved over the broad pH range of 4.5 to 6.5.Adsorption isotherms and kinetic study suggest that the sorption of Cd(Ⅱ) onto AC-T produces monolayer coverage and that adsorption is controlled by chemical adsorption.And the adsorbent has a good reusability.According to the FT-IR and XPS analyses,electrostatic attraction and cation exchange between Cd(Ⅱ) and oxygen-containing functional groups on AC-T are dominant mechanisms for Cd(Ⅱ) adsorption.

磁过滤真空阴极弧沉积技术制备及在刀具上的实验

研究了一种阴极弧沉积方法。将高端刀具放置在等电势的半球状栅网中进行钛氮化物沉积,在200V的负偏压下,完全避免了电弧的产生,X射线光电能谱(XPS)的结果表明在室温下成功地在刀具材料上沉积了钛氮化物薄膜。

Visible-Light Activities of Erbium Doped BiVO4 Photocatalysts

Er-doped BiVO4 composite photocatalyst was hydrothermal synthesized and characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray Spectroscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectra techniques. The activity of the catalyst was determined by oxidative decomposition of methyl orange in aqueous solution under visible-light irradiation. X-ray photoelectron spectroscopy and energy-dispersive X-ray Spectroscopy analysis revealed that the doped Er existed in the form of Er2O3. It also showed that the Er doping can enhance the visible-light absorption abilities of catalysts and their visible-light-driven photocatalytic activities in comparison with those of pure BiVO4.

Design of the Metal Precursors Molecular Structures in Impregnating Solutions for Preparation of Efficient Ni Mo/Al_2O_3 Hydrodesulfurization Catalysts

The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases.

Preparation of spiro-type quaternary ammonium salt via economical and efficient synthetic route as electrolyte for electric double-layer capacitor

A spiro-type quaternary ammonium salt, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate(SBP-BF4) was successfully prepared by an economical and efficient three-step process comprising the cyclization reaction of 1,4-dibromobutane and pyrrolidine, and subsequent ion exchange pathway with KOH followed by neutralization reaction via HBF4 in the system of ethanol solution. 1H NMR, 13 C NMR, FI-IR and XPS analyses showed the structure of SBP-BF4. The as-obtained SBP-BF4 was dissolved in AN and used as the electrolyte for supercapacitor. Electrochemical measurements demonstrate that, compared with commercial electrolyte TEMA-BF4/AN, SBP-BF4/AN exhibits high ionic conductivity, lower resistance and improved cycling performance, which is due to its smaller ion size and stable symmetry structure.

Integral PVA-PES Composite Membranes by Surface Segregation Method for Pervaporation Dehydration of Ethanol

A facile surface segregation method was utilized to fabricate poly（vinyl alcohol）-polyethersulfone （PVA-PES） composite membranes. PVA and PES were first dissolved in dimethyl sulfoxide （DMSO）, then casted on a glass plate and immersed in a coagulation bath. During the phase inversion process in coagulation bath, PVA spontaneously segregated to the polymer solution/coagulation bath interface. The enriched PVA on the surface was further crosslinked by glutaraldehyde. Scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS） and energy dispersive spectrometer （EDS） confirmed the integral and asymmetric membrane structure with a dense PVA-enriched surface and a porous PES-enriched support, as well as the surface enrichment of PVA. The coverage fraction of the membrane surtace by PVA reacned up to 86.8% when me PVA content m me membrane recipe was 16.7% （by mass）. The water contact angle decreased with the increase of PVA content. The effect of coagulation bath type on membrane structure was analyzed. The membrane pervaporation performance was evaluated by varying the PVA content, the annealing temperature, feed concentration and operation temperature. The membrane exhibited a fairly good ethanol dehydration capacity and long-term operational stability.

Improvement of Magnetic Field on Tribological Properties of Lubricating Oils with Zinc Butyloctyldithiophosphate

Tribological properties of 150 SN mineral oil and the oils doped with different contents of zinc butyloctyldithiophosphate(T202) under magnetic field or non-magnetic field were evaluated on a four-ball tribotester by applying an external magnetic field around the friction region. Moreover, the morphology and the tribochemical characteristics of worn surfaces were examined by a scanning electron microscope(SEM) and an X-ray photoelectron spectrometer(XPS). Then the lubrication mechanisms were discussed. The tribological test results indicated that the wear scar diameters(WSDs) of steel balls lubricated by the T202-containing lubricating oils and the friction coefficients of the corresponding oil under magnetic field were smaller than those without magnetic affection. The worn surface lubricated with the T202-formulated oils in a magnetic field was smoother than that obtained under the normal condition. Furthermore, the results of XPS analysis indicated that tribochemical films on the surfaces lubricated with T202-doped oils were mainly composed of compounds such as FeSO_4, FeS and ZnS. The atomic concentrations of oxygen, sulfur, iron, zinc and phosphorus species identified in T202 under magnetic field were higher than those without magnetic impact. It can be inferred that the improved anti-wear and friction-reducing ability of T202-doped oils was attributed to the promoted tribochemical reactions and the modification of the worn surfaces induced by magnetic field.

Preparation of Carbon Encapsulated Iron Nanoparticles with Very Thin Shells by DC Arc Discharge

Carbon encapsulated iron nanoparticles （CEINPs） with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature （AIT） of 800 ℃. The results of high resolution transmission electron microscope （HRTEM）, energy dispersive X-ray （EDX） spectroscope, X-ray diffraction （XRD）, and X-ray photoelectron spectroscope （XPS） characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5-5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24. 7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization （Ms） and coercivity （Hc） of the product B are 107.4 emu/g and 143 Oe. resnectivelv. The formation of the CEINPs in the oroduct B is discussed briefly.

Influence of NaCl deposition on atmospheric corrosion behavior of AZ91 magnesium alloy

Corrosion behavior of AZ91 magnesium alloy under NaCl particle deposition condition was investigated by gravimetric method and surface analysis technique.It was found that the mass gain increased rapidly at the beginning of exposure and then slowly with time.The corrosion morphologies were observed and the results showed that NaCl deposition resulted in the occurrence of localized corrosion.The composition of corrosion product was analyzed using X-ray photo electron spectroscopy.It was suggested that the corrosion product was a mixture of oxide and hydroxide of magnesium and aluminum.

Catalytic performance and kinetics of Au/γ-Al_2O_3 catalysts for low-temperature combustion of light alcohols

Au/γ-Al2O3 catalysts were prepared by deposition-precipitation method for the catalytic combustion of low concentration alcohol streams(methanol,ethanol,iso-propanol and n-propanol).The catalysts were characterized by X-ray photoelectron spectroscopy(XPS),X-ray diffractometry(XRD) and energy dispersive X-ray micro analysis(EDS) techniques.The XPS results showed that there was only Au0 on the surface of catalysts.The XRD patterns showed that Au was presumably highly dispersed over γ-Al2O3.The temperatures for complete conversion of methanol,ethanol,iso-propanol and n-propanol with concentration of 2.0 g/m3 were 60,155,170 and 137 ℃,respectively,but they were completely mineralized into CO2 and H2O at 60,220,260 and 217 ℃ respectively over the optimized catalyst.The activity of the catalyst was stable in 130 h.The kinetics for the catalytic methanol elimination followed quasi-first order reaction expressed as r=0.652 8c0+0.084 2.The value of apparent activation energy is 54.7 kJ/mol in the range of reaction temperature.

Study on Tribology Performance of Different Lubricant Additives under Atmospheric Pressure and High Vacuum Conditions

By using PAO-10 as the base oil, the tribological behavior of 11 additives under high vacuum condition was evaluated. By adopting some surface analytical instruments, such as scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS), the tribological mechanisms of these additives were studied. In air, O_2 can react with metal to form metal oxide that can protect the surfaces of rubbing pair during the tribological tests. According to the theory of the competitive adsorption, the function of some active elements is weakened. In a vacuum environment, the additives contributed more to the lubrication performance. The sulfur-containing additives could react with Fe to produce Fe Sx and "M—C" bonds("M" represents metal). They both had contributions to the lubrication. As for the phosphorus-containing additives, they only generated the phosphates during the tests. When the sulfur and phosphorus-containing additives were applied, the generated phosphates and Fe Sx had the primary contribution to the lubrication performance during the tests.

Synthesis and Characterization of Aluminum/Carbon Nanotubes Composites： Study of Interfacial Interaction

Abstract： In this work, the authors present a study of growth and characterization of composite based on AI and CNT （carbon nanotubes. The composites were prepared by a chemical mixing method and characterized by SEM analysis, energy dispersed X-ray measurements, X-ray photoelectron spectroscopy and cathodoluminescence spectroscopy. The analysis showed that the composites are formed by macro-cluster of aluminum oxide on a network of CNT without formation of chemical bonds at interface between particles. The results are compared with those obtained for a sample of CNT with AI traces （〈 0.5%）. They show that only the presence of metal traces changes the nanotubes optical properties, with a luminescence signal centered at about 380 nm. These luminescence signals are caused by the adhesion between CNT and AI micro-clusters that promote the formation of band gap with some local energy levels.

Shaped Pt-Ni nanocrystals with an ultrathin Pt-enriched shell derived from one-pot hydrothermal synthesis as active electrocatalysts for oxygen reduction

Alloy nanocrystals （NCs） of Pt with 3d transition metals, especially Ni, are excellent catalysts for the oxygen reduction reaction （ORR）. In this work, we, for the first time, demonstrated the water phase colloidal synthesis of Pt-M （M = Ni, Co and Fe） alloy NCs with tunable composition and morphology through a facile hydrothermal method. Pt-Ni alloy NCs synthesized with this method presented better ORR activity than commercial Pt/C catalysts. The X-ray energy dispersive spectra （EDS） mapping technique revealed that Pt-enriched shells existed on the as-synthesized Pt-Ni alloy NCs. About two atom thick layered Pt-enriched shells formed on Pts0Nis0 NCs and the thickness of the Pt-enriched shells increased as the Ni content increased. Furthermore, X-ray photoelectron spectroscopy analysis revealed that the oxidation level of the surface Pt atoms on the Pt-Ni alloy NCs decreased compared with monometallic Pt NCs, implying a decrease in the oxophilicity of the surface Pt atoms. Pt-Ni alloy NCs with lower oxophilicity of the surface Pt atoms give higher ORR activity. The most active alloy sample showed 13 times higher specific activity and six times higher mass activity at 0.9 V vs. a reversible hydrogen electrode when compared with commercial Pt/C. Pt-Ni alloy NCs also showed better durability than commercial Pt/C in long term ORR tests.

Effect of Cobalt-Doped Framework on Formation of Todorokite from Layered Manganese Oxides with Mg^(2+)/Co^(2+) Ions as Template

Cobalt （Co） exists in significant quantities in naturally occurring manganese （Mn） oxides and alters the growth of Mn oxide crystals. Four-layered Mn oxides, Na-buserite （Na-bus） and three Co-doped Na-buserite samples prepared from oxidation of Mn（OH）2 with 5%, 10%, and 20% Co/（Mn ＋ Co） molar ratios （5Co-Na-bus, 10Co-Na-bus, and 20Co-Na-bus）, were used to prepare todorokite, a common Mn oxide on the Earth＇s surface, using Mg2＋/Co2＋ ions as a template. The results showed that todorokites could be obtained by reflux treatment of Mg2＋-exchanged non-doped Na-buserite and three Co-doped Na-buserites at atmospheric pressure. However, the formation of todorokites was prohibited by reflux treatment of Co2＋-exchanged Na-bus, 5Co-Na-bus, and 10Co-Na-bus samples. Instead, todorokite was obtained by the reflux treatment of Co2＋-exchanged 20Co-Na-bus samples under atmospheric pressure. X-ray photoelectron spectroscopy analysis showed that doped Co existed as Co3＋ in the MnOs layers of doped Na-buserites. The amount of substituted Co3＋ in the MnO6 layers may play a key role in the conversion of buserite to todorokite using Co2＋ ions as a template.

Surface analysis and electrochemical behaviour of the self-assembled polydopamine/dodecanethiol complex films in protecting 304 stainless steel

A self-assembled 1-dodecanethiol film assisted with the preferential adhesion of polydopamine was prepared on the non-etching 304 stainless steel surfaces by a simple dip-coating method.The formation and surface structure of the film were characterized by water contact angle measurement,atomic force microscopy(AFM),and X-ray photoelectron spectroscopy(XPS).The corrosion behavior of the complex films was evaluated by Tafel polarization curve and electrochemical impedance spectroscopy(EIS).The excellent corrosion resistance property could be attributed to the compact hybrid film structure and superior seawater stability for modified 304 stainless steel surface.

Reductive immobilization of Re(VⅡ)by graphene modified nanoscale zero-valent iron particles using a plasma technique

Technetium-99(~99Tc),largely produced by nuclear fission of ~235U or ~239Pu,is a component of radioactive waste.This study focused on a remediation strategy for the reduction of pertechnetate(Tc O_4^-)by studying its chemical analogue rhenium(Re(VⅡ))to avoid the complication of directly working with radioactive elements.Nanoscale zero-valent iron particles supported on graphene(NZVI/r GOs)from GOs-bound Fe ions were prepared by using a H_2/Ar plasma technique and were applied in the reductive immobilization of perrhenate(Re O_4^-).The experimental results demonstrated that NZVI/r GOs could efficiently remove Re from the aqueous solution,with enhanced reactivity,improved kinetics(50 min to reach equilibrium)and excellent removal capacity(85.77 mg/g).The results of X-ray photoelectron spectroscopy analysis showed that the mechanisms of Re immobilization by NZVI/r GOs included adsorption and reduction,which are significant to the prediction and estimation of the effectiveness of reductive Tc O_4^- by NZVI/r GOs in the natural environment.

Fabrication and characterization of amorphous ITO/p-Si heterojunction solar cell

Amorphous indium-tin-oxide(a-ITO) film was deposited by radio-frequency(RF) magnetron sputtering at 180°C substrate temperature on the texturized p-Si wafer to fabricate a-ITO/p-Si heterojunction solar cell.The microstructural,optical and electrical properties of the a-ITO film were characterized by XRD,SEM,XPS,UV-VIS spectrophotometer,four-point probe and Hall effect measurement,respectively.The electrical properties of heterojunction were investigated by I-V measurement,which reveals that the heterojunction shows strong rectifying behavior under a dark condition.The ideality factor and the saturation current density of this diode are 2.26 and 1.58×10-4 A cm-2,respectively.And the value of IF/IR(IF and IR stand for forward and reverse currents,respectively) at 1 V is found to be as high as 21.5.For the a-ITO/p-Si heterojunction solar cell,the a-ITO thin film acts not only as an emitter layer,but also as an anti-reflected coating film.The conversion efficiency of the fabricated a-ITO/p-Si heterojunction cell is approximately 1.1%,under 100 mW cm-2 illumination(AM1.5 condition).And the open-circuit voltage(Voc),short-circuit current density(J SC),filll factor(FF) are 280 mV,9.83 mA cm 2 and 39.9%,respectively.Because the ITO film deposited at low temperature is amorphous,it can effectively reduce the interface states between ITO and p-Si.The barrier height and internal electric field,which is near the surface of p-Si,can effectively be enhanced.Thus we can see the great photovoltaic effect.

Stable ZnO/ionic liquid hybrid materials: novel dual-responsive superhydrophobic layers to light and anions

Novel dual-responsive superhydrophobic hybrid materials, ZnO/SAMs （self-assembled monolayers） of ionic liquids （ILs） with different counter-anions （I^-, BF4^-, PF6^- and Tf2N^-）, were synthesized and characterized. ZnO nanoparticles were first deposited on glass surfaces to produce roughness. Next, SAMs of fluorinated-alkyl-3-（3-triethoxysilylpropyl）-4,5-dihydro-imidazoliumiodide （abb. [C8Ftespim]I） were grafted onto these surfaces via -Si-O- covalent bonds using self-assembly technique. The I- ion could be subsequently exchanged with BF4, PF6-or Tf2N- through a simple aqueous anion-exchange reaction. The ZnO/ILs hybrid layers were characterized by atomic-force microscopy （AFM）, scanning-electron microscopy （SEM） and X-ray photoelectron spectroscopy （XPS）. Their wettability was estimated through the measurements of static and dynamic contact angles （CAs）. Compared to corresponding films of ZnO/[CsFtespim]I with CAs 140.7° ±2.0°, films of ZnO/[CsFtespim]PF6 and ZnO/[CsFtespim]Tf2N showed CAs with 154.0° ± 2.0° and 152.0° ± 2.0°, respectively that remained for a long time. This result suggests that anion-exchange can afford superhydrophobic materials. In addition, the wettability of ZnO/[CsFtespim]X hybrid layers can be reversibly switched by altering ultraviolet （UV） irradiation and dark storage, which shows a photo-induced reversible switch of wettability. The synergistic action of ZnO nanoparticles and SAMs of ILs produced light-anion dual-responsive superhydrophobic materials with ideal stability.