Energy Dispersive Spectrometer Mapping Research Articles

Catalytic oxidation of Benzene with manganese oxide supported on Cordierite

Volatile organic compounds (VOCs) are one of the principal causes of air pollution, posing a grave danger to the environment and human health due to their toxicity. In the presence of heat or light, catalytic oxidation has been recognized as a viable and efficient approach for VOCs remediation. Manganese-based oxides are one of the most environmentally benign and cost-effective choices for the catalytic destruction of volatile organic compounds in thermocatalysis. That is the reason why this article focused on catalytic oxidation to control benzene (a VOCs component). The wet impregnation process was used to produce manganese oxide supported on cordierites. Scanning electron microscopy (SEM), energy dispersive spectrometer mapping (EDS mapping), X-ray diffraction (XRD), and Hydrogen Temperature-programmed reduction (TPR-H2) were used to characterize the catalysts. When using the TCD-FID detector, catalytic activity measurements were done on a micro-flow reactor system coupled online to GC. The results showed that MnO2-Cor potential catalyst for completely oxidizing benzene with a 100% benzene conversion temperature of 350 C to CO2 and H2O. This catalyst provides high thermal stability and good reusability due to being carried on cordierite.

Biodistribution and Toxicological Effects of Ultra-Small Pt Nanoparticles Deposited on Au Nanorods (Au@Pt NRs) in Mice with Intravenous Injection.

Pt-based nanostructures are one of the promising nanomaterials for being used in catalysts, sensors, and therapeutics. However, their impacts on the health and biological systems are not adequately understood yet. In this work, nanorods composed of ultrasmall platinum (Pt) nanoparticles deposited on the surface and gold nanorod as the core (Au@Pt NRs) were synthesized, and the distribution and toxic effects of Au@Pt NRs were investigated in C57BL/6 mice with intravenous injection by using atomic absorption spectroscopy (AAS), transmission electron microscope (TEM), hematoxylin-eosin (HE) staining and blood cell analyzer. At the time point of Day 1, Day 8 and Day 16 post injection of Au@Pt NRs (6 mg/kg of Pt atom), Au@Pt NRs were mainly accumulated in the liver and spleen. The energy dispersive spectrometer mapping images showed Au@Pt NRs experienced quick corrosion and Au released faster than Pt in the physiological environments. The catalase (CAT) activity in tissues increased slightly in the early stage of the Au@Pt NRs exposure and went down to the normal level. With HE staining, inflammatory cells infiltration could be seen in the tissues, while no significant influences were detected on the blood biochemistry and the function of liver and kidney. In conclusion, intravenously injected Au@Pt NRs mainly distributed in the liver and spleen with comparable levels, and did not exert any significant toxic effects on the organs' function within two weeks; meanwhile, Au@Pt NRs were able to degrade, which indicated acceptable safety to the mice and potentials of biomedical application.

Long Spiky Au-Ag Nanostar Based Fiber Probe for Surface Enhanced Raman Spectroscopy.

The detection performances of noble metal-based surface enhanced Raman spectroscopy (SERS) devices are determined by the compositions and geometries of the metal nanostructures, as well as the substrates. In the current study, long spiky Au-Ag alloy nanostars were synthesized, and both core diameters and spike lengths were controlled by Lauryl sulfobetaine concentrations (as the nanostructure growth skeleton). The long spiky star geometries were confirmed by transmission electron micrograph images. Elements energy dispersive spectrometer mapping confirmed that Au and Ag elements were inhomogeneously distributed in the nanostructures and demonstrated a higher Ag content at surface for potential better SERS performance. Selected synthesized spiky nanostars were uniformly assembled on multi-mode silica fiber for probe fabrication by silanization. The SERS performance were characterized using crystal violet (CV) and rhodamine 6G (R6G) as analyte molecules. The lowest detection limit could reach as low as 10−8 M, with a 6.23 × 106 enhancement factor, and the relationship between analyte concentrations and Raman intensities was linear for both CV and R6G, which indicated the potential qualitative and quantitative molecule detection applications. Moreover, the fiber probes also showed good reproducibility and stability in the ambient atmosphere.

High-Stability Memristive Devices Based on Pd Conductive Filaments and Its Applications in Neuromorphic Computing.

Memristive devices with high-density and high-speed performance have considerable potential for neuromorphic computing applications in data storage and artificial synapses. However, current memristive devices that are based on conductive filaments, such as silver, are unstable owing to the high mobility and low thermodynamic stability of the filaments. A high-quality SnSe film was deposited using the pulsed laser deposition technology, and high-performance Pd/SnSe/NSTO devices were fabricated. High-stability memristive devices can not only implement simple arithmetic function but also exhibit the centralized distribution of SET/RESET voltage and cell-cell uniformity. The SET/RESET power can achieve approximately 4.1 and 61 μW power. The possibility of Pd filament formation and Pd2+ diffusion in SnSe thin films is first confirmed by combining high-resolution transmission electron microscopy, energy-dispersive spectrometer mapping, and first principle calculation. The formation and destruction process of Pd filaments can simulate the influx and extrusion kinetics of K+, Ca2+, or Na+ in biological synapses and implements considerable synaptic functions. This study thus provides a new idea for improving device performance using different filament materials, which can greatly facilitate the development of neuromorphic computing.

Partitioning of nitrogen atoms and its effect on retained austenite content in an ultra-low-carbon Cr–Mn–N stainless steel

The partitioning of nitrogen atoms and its effect on the retained austenite content (RAC) during quenching and partitioning (Q&P) process were investigated by dilatometry, X-ray diffraction, and field emission transmission electron microscopy with energy-dispersive spectrometer mapping in a 00Cr13Mn8N steel. Nitrogen partitioning by diffusion of N atoms from martensite to austenite occurred at 400 °C after quenching. N atoms are enriched in austenite after partitioning, and the stability of these N-rich austenite is improved and retained at room temperature during subsequent cooling. The different quenching temperatures (QTs) result in different phase fractions after partitioning. With the increase in QT, RAC first increases and then decreases, and the maximum RAC is 28.5 vol.% after quenching at 80 °C. A mathematical model was developed to rapidly and accurately characterize the phase fraction in Q&P process based on the relative length change of the samples partitioned after quenching at different QTs.

Desulfurization of gas condensate under visible light using synthesized photocatalysts of Mn/TiO2/MWCNTs and Ni/TiO2/MWCNTs

In this study, Manganese (Mn) and Nickel (Ni) doped on titanium dioxide (TiO2) were loaded on Multi-Walled Carbon Nanotubes (MWCNTs). These catalysts were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Scanning electron microscope (SEM), Transmission electron microscopy (TEM), X-ray energy dispersive spectrometer/Mapping (EDS/Map), Brunauer, Emmett, Teller (BET)/Barrett, Joyner, Halenda (BJH) and Diffuse Reflectance Spectroscopy (DRS) methods. A batch reactor was designed and photoactivity of these materials prepared under visible light irradiation was tested using dibenzothiophene (DBT). The Response Surface Methodology (RSM) based on Box–Behnken Design (BBD) was used to evaluate parameters including catalyst mass (g), time (h) and dopant percentage (wt%). The best point for maximum degradation efficiency was obtained under optimum conditions for Mn/TiO2/MWCNTs and Ni/TiO2/MWCNTs catalyst masses of 0.25 and 0.22 (g), time of 5.30 and 4.56 (h), and dopant percentage of 4.22 and 7.82 (wt%) with an efficiency of 92.82 and 98.26%, respectively. Under optimal conditions for the degradation of DBT sulfur, was investigated desulfurization of gas condensate. The highest desulfurization efficiency was obtained by Ni/TiO2/MWCNTs catalyst at 89.11%. The results of kinetic studies show that the Blanchard model has the best agreement with the experimental data.

Preparation and characterization of silica@Eu spheres

An unsophisticated preparation of silica@Eu spheres has been investigated. Many experimental tests, such as transmission electron microscopy and energy dispersive spectrometer mapping, were carried out to confirm that the rare earth complex coats the surface of silica spheres and also confirming the formation of silica@Eu. The combination of silica and a rare earth complex is realized by a simple binding force of nitrogen and fluorine in the ligand and the hydrogen bond on the surface of silica from an x-ray photoelectron spectroscopy test. The synthetic composite fluorescent microsphere greatly improves the thermal stability, as compared with a pure complex. The relationship between emission intensity and diameters of silica is also investigated. The results of the study found that as the size of silica increases, the fluorescence intensity enhances. Furthermore, the increase in size also extends the fluorescence lifetime to some extent. With the embedded structure, the europium complex has better dispersion and other properties, which means that it has broader application prospects, such as bioimaging, fluorescent markers, and optoelectronic devices.

Fabricating CoCrFeMnNi high entropy alloy via selective laser melting in-situ alloying

Quasi-equiatomic CoCrFeMnNi high entropy alloy (HEA) has been in-situ alloyed by selective laser melting (SLM) from a blend of CoCrFeNi pre-alloyed powder and Mn elemental powder. The blended powder shows good printability with various SLM parameters and the as-built HEA samples achieve a reliable forming quality. Despite the slight evaporation of Mn, energy dispersive spectrometer mapping and X-ray diffraction results show that the as-built HEA has a homogeneous chemical distribution and presents a single face-centred-cubic (fcc) phase, indicating successful in-situ alloying. The study has verified the feasibility of using blended powder to prepare high-quality HEA by SLM.

Synthesis, characterization, and visible light induced photoactivity of tourmaline-N-TiO2 composite for photooxidation of ethylene

A novel visible light driven tourmaline-nitrogen-doped-TiO2 composite (S-N-TiO2) was prepared using a facile impregnation and sol gel method and its photocatalytic reaction scheme with ethylene was proposed. X-ray diffraction analysis confirmed the presence of TiO2 in the form of anatase phase. Scanning electron microscope and energy dispersive spectrometer mapping showed that the TiO2 particles were deposited and dispersed on the surface of tourmaline. Under visible light irradiation, the S-N-TiO2 catalyst containing 4wt.% tourmaline has higher photocatalytic activity for the oxidation of ethylene than pure TiO2 and N-doped-TiO2 (N-TiO2). This enhanced activity could be not only attributed to the narrowed band gap in visible light driven N-TiO2, but also improved by the spontaneous electric field of tourmaline which was applied to restrain the recombination of the electron–hole pairs. The photogenerated electrons from N-TiO2 were induced by electric field to react with ethylene, and the leaving photogenerated holes also formed the reactive species. The photocatalytic activity of S-N-TiO2 is much affected by synthesis conditions. This novel S-N-TiO2 photocatalyst has a promising perspective in the gas treatment for air pollution control and horticultural product industries.

Polyarylene Ether Nitrile and Barium Titanate Nanocomposite Plasticized by Carboxylated Zinc Phthalocyanine Buffer.

Barium titanate (BT) and polyarylene ether nitrile (PEN) nanocomposites with enhanced dielectric properties were obtained by using carboxylatedzinc phthalocyanine (ZnPc-COOH) buffer as the plasticizer. Carboxylated zinc phthalocyanine, prepared through hydrolyzing ZnPc in NaOH solution, reacted with the hydroxyl groups on the peripheral of hydrogen peroxide treated BT (BT-OH) yielding core-shell structured BT@ZnPc. Thermogravimetric analysis (TGA), transmission electron microscopy (TEM), TEM energy dispersive spectrometer mapping, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) demonstrated successful preparation of BT@ZnPc. The fabricated BT@ZnPc was incorporated into the PEN matrix through the solution casting method. Rheological measurements demonstrated that the ZnPc-COOH buffer can improve the compatibility between BT and PEN effectively. With the existence of the ZnPc-COOH buffer, the prepared BT@ZnPc/PEN nanocomposites exhibit a high dielectric constant of 5.94 and low dielectric loss (0.016 at 1000 Hz). BT@ZnPc/PEN dielectric composite films can be easily prepared, presenting great application prospects in the field of organic film capacitors.

Cr3+ doped ZnGa2O4 far-red emission phosphor-in-glass: Toward high-power and color-stable plant growth LEDs with responds to all of phytochrome

In present work, a series of luminescent glass ceramic plates were prepared via phosphor-in-glass (PiG) technology, in which included the phosphor of ZnGa2O4:Cr3+ (ZGO:Cr3+) and glass host with composition of 30SiO2-30ZnO-22B2O3-12BaO-6Al2O3 as matrix. The structure of ZnGa2O4:Cr3+-based PiG (ZGO:Cr3+-PiG) samples are characterized by powder X-ray diffraction, scanning electron microscope, and energy dispersive spectrometer mapping. These phosphors are found to be embedded in glass matrix without interfacial reaction. In addition, the ZGO:Cr3+-PiG sample shows a quantum efficiency of ∼52.8% and its fluorescence intensity maintains 68.2% when temperature reaching 150 °C. Finally, high-power and color-stable far-red emission plant growth LEDs was fabricated by ZGO:Cr3+-PiG and 400 nm near-UV LED chip, which spectra matches well the absorption of plant's photosynthetic pigments. More importantly, it responds to all of phytochrome, triggering providing broad spectral range for plant growth LEDs.

Enhanced Dielectric Properties of Polyarylene Ether Nitriles Filled with Core–Shell Structured PbZrO3 Around BaTiO3 Nanoparticles

Core–shell structured PbZrO3@BaTiO3 nanoparticles (PZ@BT) were prepared through a modified hydrothermal method and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD). The SEM, TEM images and TEM energy dispersive spectrometer mapping demonstrate that the PZ shell successfully forms on the BT core and the thickness of the PZ shell is approximate at 20 nm. The XRD pattern demonstrates the characteristic diffraction of the PZ shell, and the XPS result also indicates the presence of lead and zirconium, which confirm the fabrication of PZ@BT. Afterwards, the PZ@BT and polyarylene ether nitrile nanocomposites (PZ@BT/PENs) were prepared, and the mechanical, thermal, and their dielectric properties were systematically investigated. With the presence of PZ@BT, the glass transition temperature of the composites is enhanced while their thermal resistance is reduced. The composites show excellent tensile strength even 50 wt.% of PZ@BT is used. After the addition of PZ@BT, the permittivity of the composites is effectively improved. Dielectric loss of the composites shows a slight decrease when the content of PZ@BT increases. Furthermore, the composite with 5 wt.% of PZ@BT shows a breakdown strength of 215 kV/mm.

Tracked changes of dolomite into Ca-Mg-Al layered double hydroxide

Abstract Dolomite is a widespread carbonate mineral that has been investigated extensively over the past two centuries. Despite the high level of investigation, aspects of the environmental conditions of crystallization, diagenesis and dissolution remain elusive and the transformation of dolomite into other value-added products is still challenging. This work shows a novel, cleaner method to dissolve dolomite by taking advantage of the acidity from the hydrolysis of Lewis acid AlCl3 and as such the mineral can be efficiently converted into Ca-Mg-Al layered double hydroxide (LDH). The dolomite and the resulting Ca-Mg-Al LDH samples were characterized by powder X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TG), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composition of the products was measured by energy dispersive spectrometer-mapping (EDS-mapping), X-ray fluorescence (XRF) and atomic absorption spectroscopy (AAS). Particle sizes of the products were measured by a dynamic light scattering method. It is documented, for the first time, that dissolution of dolomite in AlCl3 aqueous solution is facilitated by hydrothermal treatment. Well-crystallized Ca-Mg-Al LDH crystals are achieved under (Ca + Mg): Al molar ratio = 1:1, pH = 10.5 via a simple co-precipitation method. The maximum utilization efficiencies of Ca2+, Mg2+ from dolomite to LDH are 36.3% and 95.5%, respectively. The possible mechanisms of LDH formation were: 1) the dolomite dissolved in the strong acid solution due to the hydrolysis of AlCl3 and thus provided Ca2+ and Mg2+; 2) with addition of NaOH, Al3+ cations precipitated to form Al(OH)3 (at 8.3 ≤ pH ≤ 9.3) and then part of the Al(OH)3 reacted with Ca2+ and Mg2+ to form the Ca-Mg-Al LDH; 3) at pH = 10.5, the Al(OH)3 was transformed as [AlO(OH)] and meanwhile Ca2+, Mg2+ and Al3+ took part in the formation of Ca-Mg-Al LDH; 4) when pH = 10.6, [AlO(OH)] reacted with NaOH to dissolve into [Al(OH)4]− and the [Al(OH)4]− finally co-precipitated with Ca2+ and Mg2+ to form the Ca-Mg-Al LDH during heating for drying.

Synthesis of B/P/N Containing Flame‐Retardant Additives and UV Curable Hybrid Coating Applications

ABSTRACTThe aim of this study is to synthesize flame‐retardant additive by using B/P/N and to investigate this additive's performance in the ultraviolet (UV) curable system. Therefore, in the first stage, borate ester (triethanolamine borate, TEAB) was synthesized by the reaction of boric acid and triethanolamine. In the second stage, phosphate salt of borate ester (triethanolamine borate polyphosphoric acid, TEAB‐PPA) was synthesized by the reaction of borate ester (TEAB), which synthesized in the first stage and PPA. Thermal stability and flammability of the samples were evaluated by thermal gravimetric analysis, differential scanning calorimetry, and limiting oxygen index. The samples were characterized with the following analyses: Fourier transform infrared, nuclear magnetic resonance, UV transmittance, gel content, water absorption capacity, and stress–strain test. Hydrophilicity of the samples was determined by the contact angle measurements. Moreover, the surface morphology of the samples was investigated by a scanning electron microscopy–energy dispersive spectrometer mapping. The obtained results prove that boron, nitrogen, and phosphorus increased the flame retardancy property of the synthesized additive and suggest desired flame retardancy using various resins and different ratio of additives.

Correlation of structure and ion conduction in La2−xYxMo2O9 (0 ≤ x ≤ 0.2) oxygen ion conductors

Correlation of structure and ion conduction of La2−xYxMo2O9 (0 ≤ x ≤ 0.2) has been investigated. The cubic symmetry with space group P213 and other structural parameters are obtained from Rietveld refinement of X-ray diffraction patterns of Y doped samples. The average lanthanum-oxygen and molybdenum-oxygen distances are obtained from the electron density contour plot. The transmission electron microscopic study confirms the cubic nature of the samples and also provides an estimate of thickness of the grain boundary. The scanning transmission electron microscope energy dispersive spectrometer mapping confirms the different orientations of grains. The composition dependence of the ionic conductivity has been correlated with that of O2 and O3 site occupancies in the [O1La3Mo] antitetrahedral unit. The different vibrational modes in the low frequency region due to vibration of Mo-O bands are confirmed from the analysis of FTIR and Raman spectra. The full widths at half maximum of most of the Mo-O bands are found to be independent of Y doping. Additionally, the shifts in the position of Raman bands are correlated with unit cell parameter using Grüneisen constant.

Bisphenol A (BADCy)/bisphenol P (BPDCy) cyanate ester/colemanite composites: synthesis and characterization

The aim of this study was to improve thermal stability, mechanical, and surface properties of bisphenol A dicyanate ester (BADCy) with the addition of bisphenol P dicyanate ester (BPDCy) and colemanite. The cyanate esters (BADCy and BPDCy) were prepared from diphenol compound (bisphenol A or bisphenol P) and cyanogen bromide in the presence of triethylamine. The chemical structure of the synthesized cyanate esters was investigated by fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR) techniques. The cyanate esters/colemanite composites having various ratios of BADCy, BPDCy, and colemanite were prepared. Thermal stability of the samples was evaluated by thermogravimetric analysis and differential scanning calorimetry. The samples were characterized with the following analyses: gel content, water absorption capacity, and stress–strain test. Hydrophobicity of the samples was determined by the contact angle measurements. Moreover, the surface morphology of the samples was investigated by a scanning electron microscopy—energy dispersive spectrometer mapping. Finally, the obtained results prove that the prepared composites have good thermal, mechanical, and surface properties and that they can be used in many applications such as the electronic devices, materials engineering, and other emergent.

Characterization and electrochemical performance of lithium-active titanium dioxide inlaid LiNi0.5Co0.2Mn0.3O2 material prepared by lithium residue-assisted method

The lithium residues are consumed as raw materials to in-situ synthesize the LiTiO2-inlaid LiNi0.5Co0.2Mn0.3O2 composites. The effects of various LiTiO2 contents on the morphology, structure, and electrochemical properties of LiNi0.5Co0.2Mn0.3O2 materials are investigated in detail. Energy dispersive spectrometer mapping, high-resolution transmission electron microscopy and fast Fourier transform analysis confirm that the spherical particles of LiNi0.5Co0.2Mn0.3O2 are completely coated by crystalline LiTiO2 phase; X-ray diffraction, cross-section SEM and corresponding EDS results indicate that Ti ions are also doped into the bulk LiNi0.5Co0.2Mn0.3O2 with gradient distribution. Electrochemical tests show that the LiTiO2-inlaid samples exhibit excellent reversible capacity, enhanced cyclability, superior lithium diffusion coefficient and rate properties. Specially, the 3mol% LiTiO2 inlaid sample maintains 153.7mAhg−1 with 94.4% capacity retention after 100cycles between 2.7–4.4V at 1C, take 30% advantage than that of the pristine one (118.2mAhg−1). This improvement can be attributed to the removal of lithium residues and suitable LiTiO2 inlaying. The absence of lithium residue is helpful to retard the decomposition of LiPF6. While, suitable LiTiO2 inlaying can protect the bulk from directly contacting the electrolyte, buffer the volume change of core and shell during cycles, increase the surface electronic conductivity and offer a 3D path for Li+ diffusion from the bulk to interface.

High capacity Li storage in sulfur and nitrogen dual-doped graphene networks

Three-dimensional (3D) networks composing of S and N dual-doped graphene (SNG) were synthesized by a chemical vapor deposition approach using MgSO4-containing whiskers as templates and S source and NH3 as N source. Energy dispersive spectrometer mapping and X-ray photoelectron spectroscopy coupled with Raman analysis have revealed that S and N atoms with concentrations of 5.2 and 1.8atom%, respectively, have been substitutionally incorporated into the graphene networks via covalent bonds. The SNG, as an anode material for lithium ion batteries (LIBs), exhibits extremely high capacity (3525mAh/g at the current density of 50mA/g) and superior rate capability (870mAh/g at 1000mA/g) with excellent cycling stability (remaining a reversible capacity of 400mAh/g at 10A/g after 2500 cycles). The enhanced conductivity, the 3D porous network with many disorders and the intrinsically high Li storage capacity of S and N-doped carbon segments have led to the excellent electrode performance of the SNG networks. The effects of binder content and calendaring pressure on the electrode performance have been investigated. The full LIB with SNG as anode and LiCoO2 as cathode can afford a high reversible capability (164mAh/g at 0.2C) and good cycling stability.