Energy-dispersive X-ray Spectroscopy for the Quantitative Analysis of Pyrite Thin Specimens

To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantitative analysis of pyrite materials.Additionally,the k factor of pyrite is calculated experimentally.To develop an appropriate non-standard quantitative analysis model for pyrite materials,the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software.The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro-and nanoscale regions of pyrite materials.Furthermore,it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides.

Enhanced Thermoelectric Performance of Non-equilibrium Synthesized Fe0.4Co3.6Sb12-xGex Skutterudites via Randomly Distributed Multi-scaled Impurity Dots

The p-type Ge doped Fe0.4Co3.6Sb12-xGex skutterudites with multi-scaled impurity dots（500 nm-2 mm） were successfully prepared by using melt-quenching（MQ） and subsequent spark plasma sintering（SPS） technique. Compared with traditional method, the new technology significantly shortened the processing time from several days to less than 24 hours. The phase of impurity dots was demonstrated to be CoSb through analysis of X-ray diffraction（XRD） and energy-dispersive spectrum（EDS）. Impurity dots were induced by Ge substitution of Sb in the non-equilibrium synthesized process. Due to the abandonment of the long reaction of annealing crystallization, a few of Ge atoms would fail to substitute Sb site of skutterudite in this non-equilibrium synthesized process, leading to that the multi-scaled impurity dots randomly distributed in the matrix of skutterudite Fe0.4Co3.6Sb12-xGex. The combination of multi-scaled impurity dots scattering long wavelength heat-carrying phonons and the point defect scattering short and middle wavelength heat-carrying phonons dramatically made the 22.2% reduction of lattice thermal conductivity. As a result, compared with unsubstituted sample of Fe0.4Co3.6Sb12, the maximum ZT value was increased by 30.5%. Thus, the two marked features of this new synthesis process, the shortened preparation time and the enhanced thermoelectric performance, would make a promising commercial application in the future.

Calibration of Binding Energy Positions with C1s for XPS Results

The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves.When the carbon is as a major part of the inorganic material,the adventitious carbon should be identified and used as the reference.There is no adventitious carbon on the surfaces of the polymer materials,so using C1s of the carbon in the polymer itself to calibrate the charging effect is reasonable.Furthermore,compared with gold and argon,a more practical and convenient method based on C1s is proposed to get the right positions for binding energy peaks.

3D Interconnected MoO_2 Nanocrystals on Nickel Foam as Binder-free Anode for Li-ion Batteries

MoOnanocrystals(NCs) on Ni foam were simply synthesized via a facile hydrothermal method and a dip-coating method. It was worth noting that ultrafine interconnected MoOnanocrystals(about 10 nm) were uniformly anchored on Ni foam to fabricate a particular three-dimensional architecture, which may provide more active sites and shorter transmission pathways for lithium ions. As binder-free anode, MoONCs on Ni foam deliver a high initial discharge capacity of 990 mAh·gand retain a reversible capacity of 924 mAh· g(-1) after 100 cycles at a current density of 0.1 C. More importantly, when the current density returns from 2 C to 0.1 C, the capacity recovers to 910 mAh·g(-1)(about 92% of the original high capacity), suggesting excellent cycling stability and rate capability. The particular 3 D electrode as binder-free anode makes it a promising anode candidate for high-performance lithium-ion batteries.

Magnetic Properties and Nanostructures of FePtCu：C Thin Films with FePt Underlayers

Magnetic properties and nanostructures of FePtCu：C thin films with FePt underlayers （ULs） are studied. The effect of FePt ULs on the orlentation and magnetic properties of the thin films are investigated by adjusting FePt UL thicknesses from 2nm to 14nm. X-ray diffraction （XRD） scans reveal that the orientation of the films is dependent on FePt UL thickness. For a 5-nm FePtCu：C nanocomposite thin film with a 2-nm FePt UL, the coercivity is 6.S KOe, the correlation length is 59 nm, the desired face-centred-tetragonal （fct） ordered structure [Llo phase] is formed and the c axis normal to the film plane [（001） texture] is obtained. These results indicate that the beffer orientation and magnetic properties of the films can be tuned by decreasing the thockness of the FePt UL.

Denitrification performance and sulfur resistance mechanism of Sm-Mn catalyst for low temperature NH_(3)-SCR

MnO_(x)and Sm–Mn catalysts were prepared with the coprecipitation method,and they showed excellent activities and sulfur resistances for the selective catalytic reduction of NO_(x)by NH_(3)between 50 and 300℃in the presence of excess oxygen.0.10Sm–Mn catalyst indicated better catalytic activity and sulfur resistance.Additionally,the Sm doping led to multi-aspect impacts on the phases,morphology structures,gas adsorption,reactions process,and specific surface areas.Therefore,it significantly enhances the NO conversion,N_(2)selectivity,and sulfur resistance.Based on various experimental characterization results,the reaction mechanism of catalysts and the effect of SO_(2)on the reaction process about the catalysts were extensively explored.For 0.10Sm–Mn catalyst,manganese sulfate and sulfur ammonium cannot be generated broadly under the influence of SO_(2)and the amount of surface adsorbed oxygen.The Bronsted acid sites strengthen significantly due to the addition of SO_(2),enhancing the sulfur resistance of the 0.10Sm–Mn catalyst.

Ultrafast-laser-treated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)electrodes with enhanced conductivity and transparency for semitransparent perovskite solar cells

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is an important organic electrode for solution-processed low-cost electronic devices.However,it requires doping and post-solvent treatment to improve its conductivity,and the chemicals used for such treatments may affect the device fabrication process.In this study,we developed a novel route for exploiting ultrafast lasers(femtosecond and picosecond laser)to simultaneously enhance the conductivity and transparency of PEDOT:PSS films and fabricate patterned solution-processed electrodes for electronic devices.The conductivity of the PEDOT:PSS film was improved by three orders of magnitude(from 3.1 to 1024 S·cm^(–1)),and high transparency of up to 88.5%(average visible transmittance,AVT)was achieved.Raman and depthprofiling X-ray photoelectron spectroscopy revealed that the oxidation level of PEDOT was enhanced,thereby increasing the carrier concentration.The surface PSS content also decreased,which is beneficial to the carrier mobility,resulting in significantly enhanced electrical conductivity.Further,we fabricated semitransparent perovskite solar cells using the as-made PEDOT:PSS as the transparent top electrodes,and a power conversion efficiency of 7.39%was achieved with 22.63%AVT.Thus,the proposed route for synthesizing conductive and transparent electrodes is promising for vacuum and doping-free electronics.

Effect of Layered Double Hydroxides on Ultraviolet Aging Resistance of SBS Modified Bitumen Membrane

Layered double hydroxides （LDHs）/styrene-butadiene-styrene （SBS） eopolymer modified bitumen was prepared by melt blending. The effect of LDHs on the ultraviolet （UV） aging behavior of SBS modified bitumen was investigated. The changes of chemical structures of modified bitumen before and after UV aging were characterized by Fourier transform infrared spectroscopy （FTIR）. The results show that LDHs obviously reduce the variation of softening point and low temperature flexibility of SBS modified bitumen under different UV radiation intensities, which indicates that the UV aging resistance performance of SBS modified bitumen is improved effectively by LDHs. Compared with SBS modified bitumen, the changes of carbonyl, sulfoxide and butadienyl of LDHs/SBS modified bitumen decrease significantly after UV aging according to FTIR analysis, demonstrating that the oxidation and degradation reactions of SBS modified bitumen were restrained effectively by adding LDHs.

A Study of Chromium Adsorption on Natural Goethite Biomineralized with Iron Bacteria

Goethite, especially biogenic goethite, has high specific surface area and great capacity for the adsorption of many contaminants including metal ions and organic chelates. Chromium is a redox actively toxic metal ion that exists as either Cr^Ⅲ or Cr^Ⅵ in nature, and as such it is essential to understand its behavior of adsorption on natural goethite mineralized by iron bacteria, as Gallionella and Leptothrix in water body. The adsorption of Cr^3＋ and Cr^Ⅵ on naturally biomineralized goethite is studied in this paper. The results show that both Langmuir and Freundlich adsorption isothermal models are able to accurately describe the adsorption of these two ions. Investigation of SEM/EDS, TEM/EDS indicates that the two ions do not adsorb homogeneously on goethite owing to the different microstructures of goethite, and that the microspherical goethite has a greater adsorption capacity for chromium ions than the helical one. XPS data show that redox reaction of chromium on the surface of biomineralized goethite takes place in the adsorption of both Cr^3＋ and Cr^Ⅵ. The CrvI adsorbed on biogoethite is much easier to transform into CrIII than the oxidization of Cr^Ⅲ on the bio-goethite.

Preparation of Intercalated Clay/Phenolic Resin Nanocomposites under High Pressure

High pressure method was ased for the first time to produce rectorite clay （REC）/phenolic resin （PF） and organic rectorite clay （OREC） /phenolic resin and montmorillonite（ MMT）lphenolic resin （PF） nanocomposites. The structure of the material phase was studied by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, Fourier transform infrared （ FT- IR ） spectroscopy, thermogravimetric analysis （ TGA ）, and atomic force microscopg＂ （AFM）. The experimental results show that intercalated clay/resin nanocomposites could form under normal temperature and high pressure conditions by the intercalation of polymeric molecules rather than interlayer polymerization.

Second-harmonic Generation in UV-pulsed Laser Poled Amorphous 80GeS_2-15Ga_2 S_3-5CdS Chalcogenide Film

With the pulsed laser deposition （PLD） method, amorphous 80GeS2-15Ga2S3-5CdS chalcogenide film was deposited on glassy substrate. Obvious second harmonic generation （SHG） was observed in the ultraviolet （UV）-polarized film and the SHG intensity increased with the increase in single pulse energy and irradiation time. Through Raman spectra and transmission spectra, the mechanism of SHG was studied. The experimental results demonstrated that effective electron traps and hole traps were generated in the UV- polarized film. The energy of electrons and holes was using up due to the collision with other particles and crystal fields during their movement and finally they were captured by the traps and fixed, which made the electric charge distribution nonuniform in the film and destroyed the spatial isotropy. In the meantime, the center of positive and negative charges separated and a built-in electric field was formed which generated the optical second-order nonlinearity of the film.

Effect of different acid anions on highly efficient Ce-based catalysts for selective catalytic reduction of NO with NH_(3)

Three kinds of Ce-based catalysts(CePO_(4),CeVO_(4),Ce_(2)(SO_(4))_(3))were synthesized and used for the selective catalytic reduction(SCR)of NO by NH_(3).NH_(3)-SCR performances were conducted in the temperature range of 80 to 400°C.The catalytic efficiencies of the three catalysts are as follow:CePO_(4)>CeVO_(4)>Ce_(2)(SO_(4))_(3),which is in agreement with their abilities of NH_(3)adsorption capacities.The highest NO conversion rate of CePO_(4)could reach about 95%,and the catalyst had more than 90%NO conversion rate between 260 and 320°C.The effect of PO_(4)^(3–),VO_(4)^(3–)and SO_(4)^(2–)on NH_(3)-SCR performances of Ce-based catalysts was systematically investigated by the X-ray photoelectron spectroscopy analysis,NH_(3)temperature programmed desorption,H2 temperature programmed reduction and field emission scanning electron microscopy tests.The key factors that can enhance the SCR are the existence of Ce4+,large NH_(3)adsorption capacity,high and early H2 consumptions,and suitable microstructures for gas adsorption.Finally,CePO_(4)and CeVO_(4)catalysts also exhibited relatively strong tolerance of SO2,and the upward trend about 8%was detected due to the sulfation enhancement by SO2 for Ce_(2)(SO_(4))3.

Isolated atomic catalysts encapsulated in MOF for ultrafast water pollutant treatment

Atomic noble metals stand as one of the most advanced catalysts because of their unique properties and interaction with the reactants.However,due to their high activity,noble atomic catalysts tend to aggregate and deactivate in practical application.Moreover,supports aimed to disperse these atomic catalysts often suffer from weak confinement and poor porosity,thus limited the catalytic efficiency of noble atoms.Here,we report the facile encapsulation of atomic noble catalyst in cheap cerous metal-organic framework(Ce-MOF)crystals to create a robust catalyst that could deliver high catalytic performance for the reduction of 4-nitrophenol without decay in long-term cycling test.Specifically,Au atoms encapsulated in Ce-MOF exhibited ultrahigh turnover frequency(TOF)of 131 min−1 for the reduction of 4-nitrophenol in minutes,consuming only 10%precious metals compared with state-of-the-art catalysts operated under same condition.

Crystallization and micro FT-IR spectroscopy investigation of cytochrome bc_1 complex

A simple method to obtain large red crystals of cytochrome bc1 complex from beef heart mitochondria has been developed. These crystals are very stable. Their shapes are retained for a long time in tip-sealed Pasteur pipets placed in a refrigerator. The structure of crystalline cytochrome bc1 complex by micro FT-IR spectroscopy has been investigated. Based on the IR spectra of cytochrome c, the empirical assignments of the major infrared frequencies of cytochrome bc1 complex are given. Infrared frequencies and relative intensities of variable orientation and section of crystal are significantly different. These imply that infrared spectral characterization of the membrane protein crystallization is associated with the variable symmetries and orientations of the structure. Experimental results show that phospholipid exists in the crystal of cytochrome bc1 complex. The membrane protein is probably spanned on the mitochondrial membrane and buried in phospholipid bilayer in an asymmetric manner.