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Solution‐processed copper(I) thiocyanate (CuSCN) typically exhibits low crystallinity with short‐range order; the defects result in a high density of trap states that limit the device's performance. Despite the extensive electronic applications of CuSCN, its defect properties are not understood in detail. Through X‐ray absorption spectroscopy, pristine CuSCN prepared from the standard diethyl sulfide‐based recipe is found to contain under‐coordinated Cu atoms, pointing to the presence of SCN− vacancies. A defect passivation strategy is introduced by adding solid I2 to the processing solution. At small concentrations, the iodine is found to exist as I− which can substitute for the missing SCN− ligand, effectively healing the defective sites and restoring the coordination around Cu. Computational study results also verify this point. Applying I2‐doped CuSCN as a p‐channel in thin‐film transistors shows that the hole mobility increases by more than five times at the optimal doping concentration of 0.5 mol.%. Importantly, the on/off current ratio and the subthreshold characteristics also improve as the I2 doping method leads to the defect‐healing effect while avoiding the creation of detrimental impurity states. An analysis of the capacitance‐voltage characteristics corroborates that the trap state density is reduced upon I2 addition. [ABSTRACT FROM AUTHOR]

Designing cost‐effective and durable Pt‐based catalysts is vital and challenging for practicable energy storage and conversion technologies. Here, a fast phosphating strategy to establish a Pt/Pt5P2 porous nanocage with numerous heterointerfaces and defects is presented. It exhibits extraordinary activity and stability for both hydrogen evolution reaction (HER) with a small overpotential of 29 mV at 10 mA cm−2 and methanol oxidation reaction (MOR) with a high mass activity of 1.37 A mg−1Pt at peak values, surpassing Pt/C. Microstructural analyzes show that many stacking faults are induced around heterointerfaces, while rich vacancies and atomic steps are created by the phosphorus‐induced thermal migration of Pt atoms, serving as highly active low‐coordination sites. X‐ray absorption spectroscopy and theoretical calculations reveal that introducing P atoms can modify the electronic configuration of Pt, thus optimizing H2O/H* binding strength and lowering water dissociation energy to accelerate HER, while decreasing the energy barrier of the rate‐limiting step (*CHO to *HCOOH) to facilitate MOR. [ABSTRACT FROM AUTHOR]

Herein, optimization of zeolite NaA/NaX synthesis conditions in order to obtain the final product with high surface area and pore volume was investigated. An optimal synthesis condition was 5 days aging time and crystallization time of 9 h with the co-addition of cetyltrimethylammonium bromide (CTAB) and heptane. All those optimal synthesis conditions provided mixed phase between zeolite NaA and NaX, and addition of those organic phases improved the surface area and pore volume of the final synthesized zeolite. The role of CTAB and heptane on increasing the surface area of zeolite was studied by in situ small-angle X-ray scattering (SAXS). The SAXS results evidenced that small nucleation precursor was formed upon the addition of organic phase, and this nucleation precursor can provide zeolite with high-characteristic XRD signals of mixed phase of zeolite A and X after the crystallization process. The synthesized zeolite obtained from optimal synthesis condition with high surface area was further used as a catalyst support by impregnating with 5, 10, 15, and 20wt%Ni for catalyzing CO2 methanation reaction. The results found that 15wt%Ni/zeolite expressed the highest catalytic activity with high CH4 selectivity and stability. This was due to high dispersion of Ni species on catalyst surface and high metal-support interaction between Ni and zeolite. These results indicated that the mixed phase zeolite support can be a potential catalyst support for this reaction. [ABSTRACT FROM AUTHOR]

x%Ni/CeO 2 (x = 3, 6, 9, 12 and 18 wt%) catalysts were synthesized for CO 2 methanation reaction. The catalysts were prepared via sol-gel method with co-adding of citric acid to improve Ni dispersion. 18 wt%Ni/CeO 2 exhibited the highest catalytic performance. An in-situ experiment during CO 2 methanation for monitoring the oxidation state changes of Ni and Ce was conducted by TRXAS. The oxidation states of Ni2+ and Ce4+ were reduced upon increasing the reduction temperature. Moreover, Nio and Ce3+ remained unchanged during reaction. The operando XAS experiment was performed to investigate the electronic state changes of Ni species during fluctuating conditions. The state of Nio remained unchanged upon H 2 dropout and re-purging, which indicated that Ni species were completely re-reduced after H 2 was added into the feed stream again. The completely reduced behavior of Ni active species was caused by highly dispersed Ni by the addition of citric acid. [Display omitted] • CeO 2 -supported nickel catalyst was synthesized by sol-gel method with co-adding of citric acid. • 18 wt%Ni/CeO 2 catalyst exhibited the highest CO 2 methanation catalytic activity. • Added Ni was incorporated into CeO 2 lattice and those excess amount was dispersed on CeO 2 surface. • The role of citric acid was to disperse Ni by chelating process. • High dispersion of Ni species resulted in high stability of catalyst under fluctuating condition. [ABSTRACT FROM AUTHOR]

Iron(III) containing silica spheres with the average diameter of 800 nm were prepared by the hydrolysis and the condensation of tetraethoxysilane in the presence of hexadecyltrimethylammonium chloride and subsequent reaction with aqueous or ethanol solution of iron(III) nitrate. The iron(III)-containing silica spheres were calcined in air at 400 °C to obtain nanoporous silica spheres containing iron(III). The location and the states of the iron in the nanoporous silica spheres were examined using scanning electron microscopy, transmission electron microscopy, elemental mapping, diffuse reflectance ultraviolet-visible absorption as well as Fe K-edge X-ray absorption spectroscopy. Iron(III) was located at the surface of the spheres as octahedrally coordinated species when iron(III) was adsorbed from ethanol solution of iron(III) nitrate. When the incorporation of iron(III) was done from the aqueous solution of iron(III) nitrate, tetrahedrally coordinated iron(III) was dispersed homogeneously through the spherical silica particles. Both of the silica spheres were microporous with the large BET surface area (ca. 1000 m2/g). The iron(III) containing silica spheres absorbed UV and were inactive for the photocatalytic degradation of methylene blue. [Display omitted] • Silica spheres containing hexadecyltrimethylammonium were prepared by sol-gel reaction of tetraethoxysilane. • Iron(III) was incorporated into the silica as tetrahedral coordination from an aqueous solution of iron(III) nitrate. • Iron(III) was incorporated into the silica as octahedral coordination from ethanol solution of iron(III) nitrate. • The products absorbed UV (200-400 nm) while they were inactive for the photocatalytic degradation of methylene blue. [ABSTRACT FROM AUTHOR]

[Display omitted] • In 2 O 3 /ZrO 2 catalysts are prepared with different calcination temperatures of ZrO 2. • Increasing calcination temperatures strengthen the adsorption of CO 2 and H 2 on the catalysts surface. • Adsorption strength of CO 2 and H 2 determines the formation of CH 3 OH. • Weak adsorption strength facilitates the formation of CH 4. • Strong adsorption strength enhances the formation of CH 3 OH. This work investigated the role of calcination temperatures (600, 700, 800, 900 and 1000 °C) of ZrO 2 support on the physicochemical properties of In 2 O 3 /ZrO 2 catalysts (denoted as 20In/Zr-X with X, calcination temperature of ZrO 2 support) as well as their catalytic activity in CO 2 hydrogenation to methanol at high reaction temperatures (320–400 °C). The calcination temperature played a crucial role on crystal structure of In 2 O 3 and ZrO 2 , reducibility of In 2 O 3 and adsorption-desorption of CO 2 and H 2. XRD analysis revealed that cubic In 2 O 3 and amorphous ZrO 2 were presented in 20In/Zr-600. With increasing calcination temperature of ZrO 2 support from 600 to 1000 °C, the tetragonal ZrO 2 was formed and the In 2 O 3 and ZrO 2 crystallite sizes were enlarged. The degree of In 2 O 3 reduction was found to gradually decrease with increasing the calcination temperature of ZrO 2 support due to the increase of In 2 O 3 crystallite size. The adsorption strength of CO 2 and H 2 with the catalysts surface was found to be as follows: ZrO 2 > 20In/Zr-1000 > 20In/Zr-900 > 20In/Zr-800 > 20In/Zr-700 > 20In/Zr600 > In 2 O 3. The different calcination temperatures of ZrO 2 support did not significantly affect the formation of CO but strongly dominated the yield of CH 3 OH and CH 4. At reaction temperatures of 320–340 °C, the 20In/Zr-800 provided the maximum yield of CH 3 OH. However, as the reaction temperature was further increased, the maximum yield of CH 3 OH was obtained over the 20In/Zr-900, indicating that higher adsorption strength of CO 2 and H 2 enhanced the formation of CH 3 OH at higher reaction temperatures. Moreover, the strong interaction of H 2 and CO 2 with the catalysts surface suppressed the formation of CH 4. [ABSTRACT FROM AUTHOR]

Numerous studies suggest that modification with functional nanomaterials can enhance the electrode electrocatalytic activity, sensitivity, and selectivity of the electrochemical sensors. Here, a highly sensitive and cost-effective disposable non-enzymatic glucose sensor based on copper(II)/reduced graphene oxide modified screen-printed carbon electrode is demonstrated. Facile fabrication of the developed sensing electrodes is carried out by the adsorption of copper(II) onto graphene oxide modified electrode, then following the electrochemical reduction. The proposed sensor illustrates good electrocatalytic activity toward glucose oxidation with a wide linear detection range from 0.10 mM to 12.5 mM, low detection limit of 65 µM, and high sensitivity of 172 μA mM–1 cm–2 along with satisfactory anti-interference ability, reproducibility, stability, and the acceptable recoveries for the detection of glucose in a human serum sample (95.6–106.4%). The copper(II)/reduced graphene oxide based sensor with the superior performances is a great potential for the quantitation of glucose in real samples. [ABSTRACT FROM AUTHOR]

Herein, the effect of Fe3+ ions substitution on the phase evolution, microstructure, electrical, and magnetic properties of Bi0.5(Na0.68K0.22Li0.10)0.5Ti1−xFexO3 (BNKLT‐xFe) ceramics with 0 ≤ x ≤ 0.020 is investigated. The BNKLT‐xFe ceramics are synthesized via the solid‐state combustion method. All BNKLT‐xFe compositions use a calcination temperature of 750 °C for 2 h and a sintering temperature of 1025 °C for 2 h. The X‐ray diffraction (XRD) and Raman spectra illustrate coexisting rhombohedral (R) and tetragonal (T) phases in all compositions and the R phase increases with increasing Fe content. The X‐ray absorption spectroscopy (XAS) technique confirms that the local R symmetry increases from 38.8% to 67.0% with increasing x content from 0 to 0.020. The average grain size gradually increases from 0.52 to 0.84 μm when the x content increases from 0 to 0.020. At x = 0.010, the ceramic has high ferroelectric properties (Pr ≈ 26.8 μC cm−2, Ec ≈ 20.4 kV cm−1) and the highest normalized strain (d33*) of 386 pm V−1. In addition, the maximum value of the temperature‐dependent dielectric constant of 6136 is found at x = 0.015. Although BNKLT‐0Fe ceramic show diamagnetic behavior, paramagnetic behavior is observed in all Fe3+ substituted samples. [ABSTRACT FROM AUTHOR]

In this work, Co0.6Zn0.4Fe1.6Cr0.4O4 nanoparticles were synthesized by the solid state combustion technique and calcined at various temperatures from 700 to 900 °C. The phase formation, morphology and local structure of the calcined samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray absorption near edge structure (XANES) techniques. The XRD analysis revealed existence of the single-phase cubic spinel structure in the samples calcined at 900 °C. The average crystallite sizes increased as the calcination temperature increased. The XANES spectra allowed the valence states of Co2+, Cr3+, Fe3+ and Zn2+ ions in all calcined samples to be established. The clear agreement between measured and ab initio theoretical XANES spectra was the strongest evidence of Cr3+ and Zn2+ ions substituting for Co2+ and Fe3+, respectively, in CoFe2O4 inverse spinel structure. XANES results also suggested that the site occupancy of Co2+, Cr3+, Fe3+ and Zn2+ ions was mixed, with the majority Co2+ and Cr3+ ions occupying octahedral sites and the majority of Fe3+ ions occupying tetrahedral sites, while the Zn2+ ions equally occupied octahedral and tetrahedral sites in a ratio of 50:50. [ABSTRACT FROM AUTHOR]

Abstract The titanium dioxide photocatalysts modified with nitrogen (N–TiO 2) were synthesized via hydrothermal method by using urea (NH 2 CONH 2) as a nitrogen source with various concentrations of dopant. The characterizations of cooperated N–TiO 2 were examined by many techniques. The performance of the synthesized N–TiO 2 catalysts was evaluated by using the decomposition of ciprofloxacin under UV light irradiation. Additionally, the OH radical production was also estimated. The results revealed that the influence of different concentrations of nitrogen dopant was significant on the physicochemical and structural properties. The surface morphology exhibited the nanorice grain particles in all samples. The trend of particles size and pore diameter decreased, whereas BET surface area slightly increased with increasing of nitrogen contents. The WAXS profiles demonstrated that the photocatalysts displayed the high purity of the anatase crystalline phase and delayed the phase transformation from anatase to rutile. The bandgap energies showed lower than pure anatase crystalline phase. The types of Ti–N–O (substitutional N) and/or Ti–O–N (interstitial N) bonding were formed into TiO 2 lattice investigated by XPS technique. The photodegradation of ciprofloxacin increased with increasing of nitrogen contents. The N–TiO 2 catalysts can generate OH radical and in-situ OH radical thought the direct photocatalytic degradation of coumarin and ciprofloxacin, respectively. Since, increasing of nitrogen content can increasingly produce OH radical to more react with organic pollutants. The de-mineralization by using the highest nitrogen content sample showed approximately 66% removal at 4 h of reaction time. Graphical abstract Unlabelled Image Highlights • Nitrogen source in form of urea improved the photocatalytic properties of TiO 2. • Increasing of nitrogen dopant enhanced anatase phase intensity. • N–TiO 2 photocatalyst delayed the phase transformation from anatase to rutile. • Nitrogen atom incorporated into the TiO 2 lattice with substitutional and/or interstitial site. • OH radical production increased with increasing nitrogen contents. [ABSTRACT FROM AUTHOR]

Abstract This work report the structural, morphological and electrochemical properties of carbon nanofibers composited with manganese ferrite (CNF/MnFe 2 O 4) for supercapacitors. The obtained samples were characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller analyzer (BET), thermal gravimetric analysis (TGA), X-ray photoemission spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The electrochemical properties were investigated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). By increasing the carbonization temperature from 500 to 700 °C, the local structure of MnFe 2 O 4 was found to be partial inverted spinel ferrite with oxidation state of Fe3+ and Mn2+. The crystallite size, surface area, residual content of MnFe 2 O 4 , and fraction of Mn ions in tetrahedral site increased with increasing of carbonization temperature. The benefits of sample with maximum surface area, largest crystallite size, highest residual content of MnFe 2 O 4 and high fraction of Mn2+ in tetrahedral site leading to enhanced energy storage. The maximum specific capacitance of 345 Fg-1 at 2 mVs−1 (using CV) and 291.87 Fg-1 at 5 Ag-1 (using GCD) were observed. The fascinating electrochemical properties of CNF/MnFe 2 O 4 composite nanostrucutre makes it a potential candidate for high performance energy storage devices. Highlights • CNF/MnFe 2 O 4 composite nanostructures have been successfully synthesized. • Carbonization temperature influence the electrochemical performance. • Higher carbonization temperature reduced equivalent series resistances. • The existence of MnFe 2 O 4 in carbon matrix reduced the stability of electrodes. [ABSTRACT FROM AUTHOR]

In this work, vanadium‑lithium-borate glasses, 0.5V 2 O 5 –0.5(Li 2 O-xB 2 O 3 ) with x = 1.0, 2.0 and 3.0, respectively, were prepared by conventional melt-quench technique. The glass samples were characterized by X-ray diffraction, scanning electron microscopy, X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, U V –Visible Spectroscopy and vibrating sample magnetrometry. X-ray absorption near-edge spectra at the V K -edge confirmed the presence of the mixing of V 4+ and V 5+ oxidation states and X-ray photoelectron spectroscopy were used to quantify and reveal the amount of V 4+ and V 5+ in the glass samples with approximately a ratio of 1:4 for V 4+ :V 5+ . The paramagnetic behavior were found for the glass samples with x = 1.0 and 2.0 due to the presence of V 4+ . However, an influence of B 2 O 3 content clearly affected to the glass sample with x = 3.0 resulting to a diamagnetic nature of this glass composition. The local structural information around V atoms in all glass samples were addressed using extended X-ray absorption fine structure technique with a mean oxygen coordinated network of 3.50(1). The notable properties of these glasses can be used and applied in the energy storage applications. [ABSTRACT FROM AUTHOR]

The present work examined the performance of WO x /ZrO 2 catalysts calcined at different temperatures admixed with a Cu-ZnO-ZrO 2 catalyst for CO 2 -to-dimethyl ether (DME) hydrogenation. The effect of operating conditions including reaction temperature, pressure and space velocity was also investigated. The calcination temperature was found to play a crucial role on the physicochemical properties of the WO x /ZrO 2 catalysts as well as their catalytic performance. Increasing calcination temperature from 600 to 800 °C led to a gradual increase of W surface density (2.82–4.82 W nm −2 ) which was accompanied by an increase of both quantity and strength of acid sites. The WO x /ZrO 2 catalyst calcined at 900 °C showed W surface density of 9.63 W nm −2 which was higher than theoretical monolayer surface coverage of W (∼8 W nm −2 ), indicating the saturation coverage of WO x species coexisted with a small portion of nanocrystalline WO 3 . At calcination temperature of 1000 °C, the monoclinic ZrO 2 , bulk WO 3 particles and ZrW 2 O 8 phase were formed because of a drastic reduction in BET surface area (∼5 m 2 g −1 ). The CuO-ZnO-ZrO 2 catalyst admixed with WO x /ZrO 2 catalyst calcined at 900 °C exhibited the highest space-time yield of DME of 271.2 g DME  kg cat −1  h −1 during a 48-h test at 260 °C, 30 bars and a space velocity of 4333.33 mL g cat −1  h −1 . [ABSTRACT FROM AUTHOR]

Hole Transports In article number 2209504, Pichaya Pattanasattayavong and co‐workers, report that X‐ray absorption spectroscopy reveals the incomplete coordination environment around Cu(I) centers in CuSCN which can be associated with SCN− vacancies acting as hole‐trapping states. Doping with an optimal amount of I2 leads to defect‐healing and a drastic improvement in hole transport. [ABSTRACT FROM AUTHOR]

Copper(I) thiocyanate, defect healing, doping, hole transports, thin-film transistors Origin of Hole-Trapping States in Solution-Processed Copper(I) Thiocyanate and Defect-Healing by I2 Doping (Adv. Funct. Keywords: copper(I) thiocyanate; defect healing; doping; hole transports; thin-film transistors EN copper(I) thiocyanate defect healing doping hole transports thin-film transistors 1 1 1 06/22/23 20230619 NES 230619 B Hole Transports b In article number 2209504, Pichaya Pattanasattayavong and co-workers, report that X-ray absorption spectroscopy reveals the incomplete coordination environment around Cu(I) centers in CuSCN which can be associated with SCN SP - sp vacancies acting as hole-trapping states. [Extracted from the article]

A study of growth mechanism on AuNRs synthesized using seed-mediated method has been conducted via time resolved synchrotron based XAS. The synthesized AuNRs were characterized by TEM and UV–vis spectroscopy. It was found that the volume change of AgNO 3 solution influenced their surface plasmon resonances (SPR) of AuNRs. An increase of silver ions concentration resulted in an increase of the aspect ratio (AR). For the growth mechanism investigation, time-resolved XANES in fluorescent mode and UV–vis measurement were employed. The potential growth mechanism was proposed according to the XANES spectrums. The reduction of Au(3+) oxidation state to Au(0) occurs after the reducing agent were added. The change in oxidation state of the AuNRs corresponded to the XANES spectrum of AuCl illustrating the oxidation states were reduced from Au(3+) to Au(+) then Au(0), respectively. Moreover, the rate of change in oxidation state depended on the AR. The formation of AuNRs was completed for the shorter rods (AR∼2.0) while the longer rods (AR∼4.2) still exhibit higher feature of oxidation state compared at the same reaction time. In addition, the change in absorbance from UV–vis spectrums revealed that AuNRs with AR∼2.0 took 50 min to complete rod formation which is faster than that of the AuNRs with AR∼4.2 (60 min). These UV–vis results were in a good agreement with the XANES spectrums. This finding leaded to conclude that the rod formation of AuNRs with lower AR could occurred faster than the formation of AuNRs with higher AR. • Growth mechanism of gold nanorods (AuNRs). • Tunable AuNRs with various aspect ratio. • Oxidation state of Au chloride species investigated using XANES. [ABSTRACT FROM AUTHOR]

This work aims to investigate the effects of CuO doping (0–1.0 wt%) on the local structure of (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3 (BCTZ) ceramics. These samples were prepared via the solid state combustion technique using glycine as fuel. The local structure of the samples was characterized by XANES (X-Ray Absorption Near-edge Structure) spectroscopy. The Cu, Ti K-edge and Ba L3-edge XANES measurements were performed in a fluorescent mode at ambient temperature. The XANES data revealed that the oxidation state of Ba and Ti ions in all samples was +2 and +4, respectively. Comparing the experimental Cu K-edge XANES spectra to theoretical XANES spectra simulated by FEFF program suggested that the substitution of the Cu ions for B-site ions in BCTZ lattice. [ABSTRACT FROM AUTHOR]

Substitution of (Al 3+ , Nb 5+ ) co–dopants into TiO 6 octahedral sites of CaCu 3 Ti 4 O 12 ceramics, which were prepared by a solid state reaction method and sintered at 1090 °C for 18 h, can cause a great reduction in a low–frequency loss tangent (tanδ≈0.045–0.058) compared to those of Al 3+ or Nb 5+ single–doped CaCu 3 Ti 4 O 12 . Notably, very high dielectric permittivities of 2.9 − 4.1 × 10 4 with good dielectric–temperature stability are achieved. The room–temperature grain boundary resistance (R gb ≈0.37–1.17 × 10 9 Ω.cm) and related conduction activation energy (E gb ≈0.781–0.817 eV), as well as the non–Ohmic properties of the co–doped ceramics are greatly enhanced compared to single–doped ceramics (R gb ≈10 4 –10 6 Ω cm and E gb ≈0.353–0.619 eV). The results show the importance of grain boundary properties for controlling the nonlinear–electrical and giant–dielectric properties of CaCu 3 Ti 4 O 12 ceramics, supporting the internal barrier layer capacitor model of Schottky barriers at grain boundaries. [ABSTRACT FROM AUTHOR]

Due to its adaptability in scaling up, a redox flow battery (RFB) is seen to be one of the finest options for large-scale electrical backup systems. As a result, it is feasible to create RFB systems that are both cost and performance effective. Recently, a zinc-manganese RFB that relies on Zn(s)/Zn2+(aq) and Mn2+(aq)/MnO2 redox couples has gained attention since both zinc and manganese are cheap, abundant, and eco-friendly. However, the reversibility of Mn2+(aq)/MnO2 at the positive electrode is limited by the formation of Mn3+ species upon charge/discharge (CD) cycling, resulting in severe capacity fading. Herein, this study examines the use of reducing agents as electrolyte additives to enhance the reversibility of the Mn2+(aq)/MnO2 reaction. Experimental results indicate that sulfuric acid and oxalic acid as additives can significantly improve the reversibility of the Mn2+(aq)/MnO2 reaction and the cycling stability of zinc-manganese RFBs. The acetate-based system demonstrates better reversible reaction than the sulfate-based system having more than 100 CD cycles at a current density of 10 mA/cm2. Coulombic efficiency (CE) is also seen to be higher than 90%. Overall, results lead to increased efficiency and cycling stability for zinc-manganese RFBs. [ABSTRACT FROM AUTHOR]

The SUT-NANOTEC-SLRI beamline was constructed in 2012 as the flagship of the SUT-NANOTEC-SLRI Joint Research Facility for Synchrotron Utilization, co-established by Suranaree University of Technology (SUT), National Nanotechnology Center (NANOTEC) and Synchrotron Light Research Institute (SLRI). It is an intermediate-energy X-ray absorption spectroscopy (XAS) beamline at SLRI. The beamline delivers an unfocused monochromatic X-ray beam of tunable photon energy (1.25-10 keV). The maximum normal incident beam size is 13 mm (width) × 1 mm (height) with a photon flux of 3 × 108 to 2 × 1010 photons s−1 (100 mA)−1 varying across photon energies. Details of the beamline and XAS instrumentation are described. To demonstrate the beamline performance, K-edge XANES spectra of MgO, Al2O3, S8, FeS, FeSO4, Cu, Cu2O and CuO, and EXAFS spectra of Cu and CuO are presented. [ABSTRACT FROM AUTHOR]

Giant dielectric permittivity (ε′) with low loss tangent (tanδ) was reported in (In + Nb) co-doped TiO2 ceramics. Either of electron-pinned defect-dipole or internal barrier layer capacitor model was proposed to be the origin of this high dielectric performance. Here, we proposed an effectively alternative route for designing low-tanδ in co-doped TiO2 ceramics by creating a resistive outer surface layer. A pure rutile-TiO2 phase with a dense microstructure and homogeneous dispersion of dopants was achieved in (In + Nb) co-doped TiO2 ceramics prepared by a simple sol-gel method. Two giant dielectric responses were observed in low- and high-frequency ranges, corresponding to extremely high ε′≈106-107 and large ε′≈104-105, respectively. After annealing in air, a low-frequency dielectric response disappeared and could be restored by removing the outer surface of the annealed sample, indicating the dominant electrode effect in the initial sample. Annealing can cause improved dielectric properties with a temperature- and frequency-independent ε′ value of ≈1.9 × 104 and cause a decrease in tanδ from 0.1 to 0.035. High dielectric performance in (In0.5Nb0.5) xTi1− xO2 ceramics can be achieved by eliminating the electrode effect and forming a resistive outer surface layer. [ABSTRACT FROM AUTHOR]

The high permittivity of CaCu 3 Ti 4 O 12 ceramics has attracted considerable attention in recent years due to their potential applications in electronic devices. However, their dielectric loss tangents are still too large. Here, we report of achieving a greatly decreased loss tangent with retaining high permittivity in Zn-doped CaCu 3 Ti 4 O 12 ( x =0–0.10) ceramics prepared using a modified sol–gel method. The influences of Zn 2+ doping on the microstructure, giant dielectric response, and non–Ohmic properties as well as microscopic effects on the electrical properties of grain and grain boundary were systematically studied. In addition to their dielectric properties, their non–Ohmic properties were remarkable improved. Very–low loss tangents (tanδ~0.016–0.017) and high permittivities (ε′~6500–7700) at 1 kHz were successfully achieved in CaCu 3 -x Zn x Ti 4 O 12 ceramics with x =0.05–0.10. Substitution of Zn 2+ ions into Cu 2+ sites caused an increase in the total resistance, which was governed by the grain boundary resistance. The potential barrier height of CaCu 3 Ti 4 O 12 ceramics was significantly increased by Zn 2+ dopant ions. The reduced apparent tanδ and improved nonlinear electrical properties were primary attributed to the modified grain boundary response as a result of Zn 2+ doping. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4) was synthesizedviaethanol-assisted solvothermal method performing at heating temperature of 200°C for 2–6 h. Characteristics of BiVO4were investigated by X-ray diffraction, field emission-scanning microscopy and Brunauer, Emmett and Teller technique. Single monoclinic phase with T-shape like particles was obtained and average crystalline sizes as well as surface area were improved by a prolonged reaction time. Electron transitions in the structure were described by diffuse reflectance of the BiVO4. Moreover, X-ray absorption spectra at vanadium K-edge were presented in more information of chemical structure of vanadium's oxidation state and bond distance between vanadium and oxygen. [ABSTRACT FROM AUTHOR]

L 3 -edge Extended X-ray Absorption Fine Structure (EXAFS) studies have been carried out on a praseodymium gallate glass (Pr 3 Ga 5 O 12 ) prepared by aerodynamic levitation and laser heating. The short range ordering around the rare-earth has been obtained by combined technique including molecular dynamics simulation (MD). The results give an average Pr O coordination number of 6.68(2) and a mean Ga O coordination number of 4.29(2). A good agreement between the experimental data and the simple molecular dynamics simulations give rising a glass network of a Pr O polyhedral structure and a predominant GaO 4 tetrahedral network in this glass. [ABSTRACT FROM AUTHOR]

We report room temperature ferromagnetism in ∼30–60 nm nanofibers of Ce 0.96 Fe 0.04 O 2 calcined at 500, 600, 700, and 800 °C. The as-spun nanofibers were fabricated by electrospinning technique. Nanofibers of the as-spun and calcined samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and vibrating sample magnetometer (VSM). The XRD and TEM with selected electron diffraction (SEAD) analysis results indicate that the Ce 0.96 Fe 0.04 O 2 nanofibers have a cubic perovskite structure without any secondary phase. The as-spun samples exhibit a diamagnetic behavior, whereas the calcined Ce 0.96 Fe 0.04 O 2 samples are ferromagnetic having the specific magnetizations of 0.002–0.923 emu/g at 10 kOe. The results from XAS spectra show the valence state of Fe 3+ and Fe 2+ mixed in the Ce 0.96 Fe 0.04 O 2 samples indicating oxygen vacancies in the nanofibers. Similarly, the results XPS spectra show that there are oxygen vacancies in the nanofibers as a result of Ce 3+ on the surface. These oxygen vacancies play an important role to induce room temperature ferromagnetism (RT-FM) in the calcined Ce 0.96 Fe 0.04 O 2 nanofibers. Our results indicate that the ferromagnetic properties of Ce 0.96 Fe 0.04 O 2 system are intrinsic and are not a result of any secondary magnetic phase or cluster formation. It is suggested that the electrospun Ce 0.96 Fe 0.04 O 2 nanofibers can be further developed for many applications including ferrofluids, magnetic recording, biomedicine, and spintronics. [ABSTRACT FROM AUTHOR]

Dielectric properties of Ca 1−3 x /2 Yb x Cu 3− y Mg y Ti 4 O 12 ( x =0.05, y =0.05 and 0.30) prepared using a modified sol–gel method and sintered at 1070 °C for 4 h were investigated. The mean grain sizes of the CaCu 3 Ti 4 O 12 and co-doped Ca 0.925 Yb 0.05 Cu 3− y Mg y Ti 4 O 12 ( y =0.05 and 0.30) ceramics were ≈15.86, ≈3.37, and ≈2.32 μm, respectively. Interestingly, the dielectric properties can be effectively improved by co-doping with Yb 3+ and Mg 2+ ions to simultaneously control the microstructure and properties of grain boundaries, respectively. These properties were improved over those of single-doped and un-doped CaCu 3 Ti 4 O 12 ceramics. A highly frequency−independent colossal dielectric permittivity (≈10 4 ) in the range of 10 2 –10 6 Hz with very low loss tangent values of 0.018–0.028 at 1 kHz were successfully achieved in the co-doped Ca 0.925 Yb 0.05 Cu 3− y Mg y Ti 4 O 12 ceramics. Furthermore, the temperature stability of the colossal dielectric response of Ca 1−3 x /2 Yb x Cu 3− y Mg y Ti 4 O 12 was also improved to values of less than ±15% in the temperature range from −70 to 100 °C. [ABSTRACT FROM AUTHOR]

Carbon/manganese ferrite (C/MnFe 2 O 4 ) composite nanofibers were fabricated using electrospinning technique followed by carbonization process under mixed of air and argon atmosphere at 400, 600 and 800 °C, respectively. The prepared composite nanofibers were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and X-ray absorption spectroscopy (XAS) including X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). After calcination at 800 °C, the composite nanofibers of C/MnFe 2 O 4 were obtained with a mean diameter of nanofibers of approximately 700–800 nm. The structure of MnFe 2 O 4 was successfully studied using XAS technique and was found to be cubic spinel with a coupling of Mn 2 /Mn 3+ and Fe 3+ oxidation states. All composite nanofibers exhibited ferromagnetic behavior especially after being calcined at 800 °C. This ferromagnetic properties were related to the distribution of cations over tetrahedral and octahedral sites as revealed by EXAFS results. [ABSTRACT FROM AUTHOR]

A novel strategy to improve the dielectric properties of CaCu 3 Ti 4 O 12 ceramics was proposed by co-doping with Sm 3+ and Mg 2+ . Sm 3+ substituted in Ca 2+ sites can effectively suppress the grain growth, achieving a fine grained ceramic microstructure. Mg 2+ was selected to be substituted into Cu 2+ sites to enhance the grain boundary (GB) resistivity for reducing the loss tangent (tanδ). High dielectric permittivity ϵ ′ ≈ 1.25 × 10 4 and low tanδ ≈ 0.039 at 1 kHz were successfully accomplished in a Ca 0.925 Sm 0.05 Cu 2.70 Mg 0.30 Ti 4 O 12 ceramic. Non-Ohmic properties were also enhanced. A slight increase in Ti 3+ /Ti 4+ ratio in (Sm + Mg) co-doped CaCu 3 Ti 4 O 12 ceramics was confirmed by the X-ray absorption near edge structure. Changes in tanδ values for all the co-doped ceramics were very consistent with their variations in GB resistance. The dielectric and non-Ohmic properties of co-doped ceramics were significantly improved by tuning both the geometric and intrinsic factors, i.e., increasing the density of GB layer and enhancing the GB resistance, respectively. [ABSTRACT FROM AUTHOR]

This work presents the structural study of La 1− x − y Gd x Sr y MnO 3 or LGSM compositions where 0 ⩽ x ⩽ 0.15 and 0 ⩽ y ⩽ 0.45, respectively. In particular, the effect of doping Gd concentration and the size mismatch of A-site cations from the substitution of Gd for La on the MnO 6 octahedral structure is focused as the average size of the cations occupying in A-site is fixed. The LGSM nanoparticles are carefully studied and analyzed using X-ray diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) including X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS). The XRD results obtained from Rietveld refinement show that all nano-powder samples have rhombohedral structure. From the XANES technique we found that the effect of Gd substitutions causes the slight increase of mean oxidation state of Mn from 3.50 to 3.65. Furthermore, the results of MnO 6 octahedral analysis obtained from EXAFS technique show that the local structure around Mn atoms for LG05 and LG10 samples can be explained by 4(s) + 2(l) model while the LG15 sample can be explained by 6 model. [ABSTRACT FROM AUTHOR]

Post‐coordination design on covalent organic frameworks (COFs) is an efficient strategy for elevating the photocatalytic activity of organic moiety. However, the rigid skeletons and densely layered stacking of two‐dimensional (2D) COFs cannot be flexibly adapted for specific conformations of metal complexes, thereby impairing the metal‐COF cooperation. Here, we adopt a solvothermal method to immobilize nickel(II) ions into a 2,2′‐bipyridine‐containing 2D COF, forming a stable coordination motif. Such the complex remarkably enhances the photocatalytic performance, giving an optimized H2 evolution rate of as high as 51 300 μmol h−1 g−1, 2.5 times higher than the pristine COF. The evolved hydrogen gas can also be detected upon 700‐nm light irradiation, while its analog synthesized by the traditional coordination method is photo‐catalytically inert. This work provides a strategy for optimizing the metal‐COF coordination system and strengthening a synergy for electronic regulation in photocatalysis. [ABSTRACT FROM AUTHOR]

Post‐coordination design on covalent organic frameworks (COFs) is an efficient strategy for elevating the photocatalytic activity of organic moiety. However, the rigid skeletons and densely layered stacking of two‐dimensional (2D) COFs cannot be flexibly adapted for specific conformations of metal complexes, thereby impairing the metal‐COF cooperation. Here, we adopt a solvothermal method to immobilize nickel(II) ions into a 2,2′‐bipyridine‐containing 2D COF, forming a stable coordination motif. Such the complex remarkably enhances the photocatalytic performance, giving an optimized H2 evolution rate of as high as 51 300 μmol h−1 g−1, 2.5 times higher than the pristine COF. The evolved hydrogen gas can also be detected upon 700‐nm light irradiation, while its analog synthesized by the traditional coordination method is photo‐catalytically inert. This work provides a strategy for optimizing the metal‐COF coordination system and strengthening a synergy for electronic regulation in photocatalysis. [ABSTRACT FROM AUTHOR]

In this work, 2 wt%Pt/TiO 2 , 20 wt%Ni/TiO 2 monometallic catalysts and xwt%Pt−20 wt%Ni/TiO 2 (x = 1, 2 and 4 wt%) bimetallic catalysts were synthesized by one-pot sol-gel method for CO 2 methanation reaction. All bimetallic catalysts revealed higher CO 2 conversion than both monometallic catalysts. The 2 wt%Pt−20 wt%Ni/TiO 2 catalyst exhibited the highest percentage of CO 2 conversion at low reaction temperature, with almost 100% CH 4 selectivity and high stability during 72 h time on stream. The effect of Pt co-doped with Ni to bimetallic formed on the catalyst properties was studied using several techniques, including X-ray diffraction, N 2 adsorption-desorption, Raman spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, H 2 temperature-programmed desorption, H 2 temperature-programmed reduction, CO 2 temperature-programmed desorption and X-ray absorption spectroscopy (both ex-situ and in-situ experiments). The results showed that Pt was dispersed on the catalyst surface in the form of platinum oxide, while Ni was both incorporated into the TiO 2 lattice with the excess amount from saturated level being dispersed on the catalyst surface. The results from XAS evidenced that some electrons movement from Ni to Pt occurred. This electronic property changing can tune the interaction between Ni and TiO 2 support with appropriate strength and then resulting in higher reducibility of the catalyst and higher dispersion of Ni species. Furthermore, the electron-rich Pt site on the catalyst surface favored to adsorb CO from CO 2 dissociation and further activated adsorbed CO to interact with nearby hydrogen atoms to form CH 4 leading to high CO 2 methanation activity at low temperature. [Display omitted] • The Pt−Ni bimetallic promoted CO 2 methanation toward lower reaction temperature. • The role of Pt was to withdrawn the electron from valence d state of Ni. • Electron movement between Ni and Pt tuned the interaction between metal-support. • Pt promoted CO dissociation barrier by weakening of C-O bonding. [ABSTRACT FROM AUTHOR]

Giant dielectric behavior and electrical properties of CaLuCuTiO ceramics were studied by focusing on the influences of Lu doping on their microstructure and electrical properties. The mean grain size of CaCuTiO was greatly reduced as the dopant content was increased to 15 at.% ( x = 0.15), which was ascribed to the effect of solute drag. X-ray absorption near-edge structure confirmed the presence of Ti ions in CaLuCuTiO ceramics. The ratio of Ti/Ti in CaCuTiO was reduced by Lu doping. Dielectric permittivity ( ε′) decreased with increasing Lu content, which was ascribed to reduce grain boundary capacitance caused by the presence of Lu. Activation energies for conduction in the grain interiors and at the grain boundaries were slightly changed with Lu content. Interestingly, improved dielectric properties with ε′ ~3.56 × 10 and tan δ ~0.059 at 1 kHz in the CaLuCuTiO ceramic were achieved. [ABSTRACT FROM AUTHOR]

Ba0.09Al0.18Ti0.12O0.61 glasses have been produced by aerodynamic levitation and laser heating. Neutron diffraction, x-ray diffraction, x-ray absorption spectroscopy, molecular dynamics simulation, and reverse Monte Carlo refinement methods have been used to obtain a detailed atomistic structural model of the glass. This model has been used to investigate its atomic coordination and network structure. It is found that the A1 atoms are almost exclusively fourfold tetrahedrally coordinated to oxygen atoms. In contrast, the Ti atoms coordinate to oxygen atoms in approximately equal numbers of four- and fivefold coordinated sites with a small number of sixfold sites. The results show the presence of some tetrahedral TiO4 structural motifs although the dominant O-Ti-O bond angle occurs at 90° . It is found that Al/Ti-O network structure shows strong similarities with other oxide glass forming systems although a first sharp diffraction peak is not observed. The results are used to discuss the unusual properties of the Ba-Al-Ti-O glasses produced under different quenching conditions. [ABSTRACT FROM AUTHOR]

Nanocrystalline powders of yttrium iron garnet (Y 3 Fe 5 O 12 ) were synthesized using egg white-based sol–gel method. Garnet samples were obtained after calcination in air at 700, 800, 900, and 1000 °C for 3 h. Polycrystalline phases occurring in samples are investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Magnetic properties of the samples were measured using the vibrating sample magnetometer (VSM). X-ray absorption spectroscopy (XAS) including X-ray absorption near edge structure (XANES) and X-ray absorption fine structure (EXAFS) was employed in order to reveal the oxidation state and local structure around Fe atoms in the prepared samples. From XANES study we found that Fe ions in all samples show the oxidation states of 3+ in the tetrahedral and octahedral sites in the structure. In addition, the Fe–O distances (1st shell) in all garnet samples keep the same value, 1.80 ± 0.02 Å. In contrast, the Fe–Fe and Fe–Y distances are significantly different when the samples were calcined at different temperatures. [ABSTRACT FROM AUTHOR]

Mo3Sb7 has been known as a p-type metal with commonly poor thermoelectric properties. However, Mo3Sb7 can be a high-efficiency thermoelectric material, owing to its capability of a metal–semiconductor transition, which can be realized by adding two valence electrons through elemental substitutions. Among the Mo3Sb7-based compounds, Mo3Sb5.4Te1.6 shows the highest figure of merit, zT, but additional valence electrons are needed for further improvement of the figure of merit. Here, we try to enhance the figure of merit of Mo3Sb7 by iodine-doping and by synthesizing and characterizing Mo3Sb7Ix with x = 0, 0.50, 0.75, 1.00, 1.25, and 1.50, where antimony (valence electrons = 5) is replaced by iodine (valence electrons = 7). We confirmed that the solubility limit for iodine in Mo3Sb7Ix was 1.25 < x < 1.50, and the figure of merit was enhanced by approximately 65% in maximum in x = 1.25. [ABSTRACT FROM AUTHOR]

In this work, Mn 1-x Zn x Fe 2 O 4 powders (x = 0.0, 0.2, 0.4, 0.6 and 0.8) were prepared by a conventional solid-state reaction method. The phase formation, local structure and cation distribution of Mn 1-x Zn x Fe 2 O 4 ferrite samples were investigated by X-ray Diffraction (XRD) and X-ray Absorption Near Edge Structure (XANES) Spectroscopy techniques. XRD analysis reveals that the single cubic spinel phase was formed in all prepared samples. The average crystallite size decreases with increasing zinc concentration. XANES measurements showed that the oxidation states of Fe and Zn ions in doped samples are +3 and + 2, respectively. The feature of the measured Fe, Mn and Zn K-edges XANES spectra are compared with the simulated XANES spectra obtained by using linear combination of the proportion of the distribution of Fe, Mn and Zn ions within the spinel structure. It is shown that a satisfactory agreement for the XANES Fe, Mn and Zn K-edges of Mn 1-x Zn x Fe 2 O 4 powders can be obtained introducing a mixed spinel structure with the majority of Fe3+ ions occupying tetrahedral sites and the majority of Zn2+ ions occupying octahedral sites. While, Mn2+ and Mn3+ ions were found to occupy both tetrahedral and octahedral sites with a higher stronger preference to be at the tetrahedral sites. • Mn 1-x Zn x Fe 2 O 4 powders (x = 0.0, 0.2, 0.4, 0.6 and 0.8) were prepared by a conventional solid-state reaction method. • Synchrotron X-ray absorption technique in characterizing local structure and cation distribution of Mn 1-x Zn x Fe 2 O 4 materials. • The results were confirmed with simulated XANES spectra. [ABSTRACT FROM AUTHOR]

The present study reports a structural change of subchondral bone samples obtained from the patients who suffer from osteoarthritic knee (OA). The structural study was undertaken by comparison between controlled patients aged below 50 years old and OA patients aged over 50 years old. By employing Synchrotron-based X-ray fluorescence (SR-XRF) and X-ray absorption spectroscopy (XAS) techniques including X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), the evidence of bone changes in term of Calcium–Phosphorus (Ca–P) contents were revealed. SR-XRF results excited at 2350 eV for P elements were used to clearly identify the amount of phosphorus contents in subchondral bone structure. The result showed the P contents in patients aged above 50 years old (OA) are lower than controlled patients. The depth information obtaining from both XANES and EXAFS results at P K-edge is related to electron transitions and structural modification especially around P ions at different ages. Lower Ca–P proportions which are caused the osteoporosis were obviously found in the elder patients. In addition, the majority amorphous structure of Ca–P is mainly found in all bone samples. • Bone changes in knee osteoarthritis were studied using SR-based techniques. • Both SR-XRF and XAS data were used to reveal changes of P in bone samples. • Changes in terms of electronic and atomic structures of P-contents were reported. [ABSTRACT FROM AUTHOR]

Aqueous zinc (Zn)‐based structural batteries capable of both electrochemical energy storage and mechanical load‐bearing capabilities are attractive for next‐generation energy storage for future electric vehicles due to their eco‐friendliness, non‐toxic, and safe nature. However, parasitic free water activities plague aqueous Zn‐based batteries, detrimental to the electrochemical performance and longevity of the cell. Developing polymer gel electrolytes is a notable potential solution, but they usually have poor electrode interfacial interactions and inadequate mechanical properties. This article introduces a novel non‐fibrous highly amorphous cellulose polymer electrolyte "Cellyte" for aqueous structural Zn‐based batteries. Cellyte exhibits a high strength of ≈24 MPa and Young's modulus of ≈380 MPa, along with the ability to suppress parasitic water activity. The symmetric Zn||Cellyte||Zn cell therefore demonstrates excellent cycling stability of over ≈3000 h. Cellyte can also serve as the binder for the structural cathode material, creating a continuous polymer electrolyte–cathode interface, thereby increasing mechanical robustness and decreasing interfacial resistances of the battery, allowing the structural Zn||Cellyte||LMO‐CF battery to achieve high electrochemical performance with excellent cycling stability over 1200 h with ≈91.5% capacity retention. This provides a pathway to design mechanically robust, electrochemically performing, and safe structural batteries. [ABSTRACT FROM AUTHOR]

Local structures and mechanisms for n -pentane aromatization on Ga embedded H-ZSM-5 zeolite (Ga/ZSM-5) were elucidated using Synchrotron-based X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations to understand the role of Ga/ZSM-5 zeolite in aromatics synthesis. XAS data suggests that Ga ligates with four oxygen or four hydrogen atoms. Catalytic tests results suggest that conversion by Ga/ZSM-5 catalyst cannot occur via C6–C8 non-aromatic intermediates, while the availability of Ga metal sites promotes the aromatization of C2 and C3 species. Therefore, conversion of n -pentane to benzene or toluene comprises four steps, i) cracking, ii) GaH 2 activation, iii) cyclization, and iv) dehydrogenation. Our model predicts the key intermediate in n -pentane aromatization on Ga/ZSM-5 zeolite to be a five-membered Ga-C4 ring structure. The ring undergoes expansion to form a seven-membered Ga-C6 ring. Moreover, we discuss thermodynamics and kinetic results for the benzene and toluene formation pathways. Our results provide new finding for the role of Ga/ZSM-5 zeolites in n -pentane aromatization processes. Image 1 Our model predicts the key intermediate in n-pentane aromatization on Ga/ZSM-5 zeolite to be a five-membered Ga-C4 ring structure via ethylene precursors. • Combined DFT and Synchrotron-based XAS were employed to mechanistic study of pentane aromatization on Ga/ZSM-5 catalyst. • The cyclization step involves with ethylene precursors at Ga site in Ga/ZSM-5 catalyst instead of long chain (C6) diene.. • Our results provide new finding for the role of Ga/ZSM-5 zeolites in n-pentane aromatization processes. [ABSTRACT FROM AUTHOR]

In this research, the synthesis of lithium silicon vanadium pentaoxide compounds is performed by the solid-state reaction and heated by a microwave. This combines the advantages of a solid-state reaction and the microwave method. The precursors were lithium nitrate, vanadium pentaoxide, and silica from rice husk ash. The conditions were studied according to grinding time and microwave heating. Each condition was examined for electrochemical properties by cyclic voltammetry. The grinding time at 6 hr and heating at 600 W for 5 min provided the highest specific capacitance of 376 F g−1. The product morphology was determined to be irregular in shape by scanning electron microscopy. The X-ray diffraction and transmission electron microscopy results identify that the product was Li3.6Si0.6V0.4O4. X-ray absorption near edge structure technique found the oxidation of vanadium was V4+ and V5+. Fourier transform infrared spectroscopy and resonance Raman spectroscopy exhibited the bonds of Si − O, Li − O, V − O − V, V = O and Si − O−Si. [ABSTRACT FROM AUTHOR]

Recent development of manganese-lithium borate glasses for applications as supercapacitor was reported. The glasses were prepared by melt-quench technique and characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and Uv–visible spectroscopy (UV-VIS). The paramagnetism of synthesized glasses was observed at room temperature measured by vibrating sample magnetometry (VSM). The electrochemical properties were studied by cyclic voltammetry (CV). The specific capacitance of 0.2MnO 2 -0.8(Li 2 O- x B 2 O 3) glasses were increase from 144 F g−1 to 196 F g−1 for x = 1 to x = 3 (mol%) with scanning rate of 5 mV s−1. However, the specific capacitance was decrease when x = 4. To understand the structure-function of these glasses, the x-ray absorption spectroscopy (XAS) was also used to study a local structure and oxidation state of Mn content in these glasses. Mixing of Mn2+/Mn3+ oxidation state was exhibited with the mean Mn–O bonding distance of approximately 2.0495 Å. • Manganese lithium borate glasses were prepared by conventional melt-quench technique. • XRD, SEM, XAS, UV–Vis, VSM were used to reveal the structure-function of glasses. • The mixing of Mn2+ and Mn3+ oxidation states were qualitatively observed. • The CV curves with specific capacitance calculation were carefully studied for all glasses. • The notable properties of these glasses suggests a possibility in using as cathodes of Li-ion batteries. [ABSTRACT FROM AUTHOR]

Consumption of water containing high proportions of manganese could cause Parkinson's like symptoms and damage the central nervous systems. This study aims to investigate the potential of manganese removal through the development of microbial cell-immobilized biochar. The wood vinegar industry generates a large volume of carbonized wood waste (natural biochar) from the pyrolytic process. This is the first investigation utilizing this low value waste combined with biological treatment for water purification. Raw and hydrogen peroxide-modified biochars were used to immobilize an effective manganese-oxidizing bacterium, Streptomyces violarus strain SBP1 (SBP1). The results demonstrated that the modified biochar had a higher proportion of oxygen-containing functional groups leading to better manganese removal. Manganese adsorption by the modified biochar fitted pseudo-second-order and Langmuir models with the maximum adsorption capacity of 1.15 mg g−1. The modified biochar with SBP1 provided the highest removal efficiency at 78%. The advanced synchrotron analyses demonstrated that manganese removal by the biochar with SBP1 is due to the synergistic combination of manganese adsorption by biochars and biological oxidation by SBP1. Unlabelled Image • Cell-immobilized biochar removed manganese well (up to 78%). • Biochar adsorbed Mn (II) and immobilized cells oxidized Mn (II) to Mn (III). • Biochar adsorbed manganese for 34–63%. • Manganese adsorption isotherm followed both Langmuir and Freundlich models. [ABSTRACT FROM AUTHOR]

A robust method for enhancing the dispersion and stabilization of small metal nanoparticles in heterogeneous catalysts is developed. It involves in situ complexation of palladium(II) by histidine, in water, prior to impregnation in fumed silica. TEM images show that the histidine facilitates dispersion of the Pd(II) into finer nanoscale particles (≈2 nm) uniformly distributed on the support, rather than the large clusters (≈5 nm) seen in the absence of histidine. After hydrogen reduction, assessments using CO chemisorption and propylene hydrogenation indicate that the coordinated histidine might obscure the active sites on the Pd particles. However, as histidine decomposes between 220 and 300 °C in air, these materials are treated at 225 °C in air for 48 h. Afterwards the Pd(II) particles remain the same size, but after hydrogen reduction, there is a 2.4‐fold increase in CO gas adsorption, indicative of an expanded Pd surface area. Furthermore, superior catalyst stability (activity >200 h) is observed during propylene hydrogenation at 250 °C. This is consistent with histidine use having generated widely spaced, uniformly small, Pd nanoparticles on the silica support which is expected to help prevent agglomeration (sintering) during catalysis. This is a convenient low‐cost strategy for reducing metal content, preventing sintering and optimizing catalyst performance. [ABSTRACT FROM AUTHOR]

In this study, cryptomelane-type manganese oxide (K-OMS-2) was used as a catalyst for the thermal oxidation of toluene. The catalyst was synthesized via the hydrothermal route and doped with Cu, Ce, and co-doped with the same metals by ex-situ and in-situ methods. The effects of dopant type, dopant concentration, and dopant impregnation method on the thermal catalytic activity of K-OMS-2 were examined. Initially, 1%, 2%, and 4% by mole Cu or Ce were incorporated by wet impregnation to the hydrothermally synthesized K-OMS-2 and in-situ direct hydrothermal method. The physicochemical properties were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES), and thermal gravimetric analysis (TGA) techniques. Gaseous toluene was made to react with the doped catalysts in a packed bed reactor attached to gas chromatography equipment to measure the amount of unreacted toluene. Results showed K-OMS-2 doped with 4% by mole Cu and 1% by mole Ce gave excellent thermal catalytic efficiency results at 180 °C reaction temperature. Meanwhile, K-OMS-2 co-doped with Ce and Cu with a mole ratio of 0.25:3.75 per 100 moles of K-OMS-2 gave the best catalytic activity and complete oxidation at 180 °C reaction temperature. Comparing K-OMS-2 doped with the same metal ratios, in situ doped catalysts led to higher toluene removal percentages. Meanwhile, the 72-h stability test showed that the optimum co-doped catalysts are capable of entirely oxidizing toluene even after prolonged and continuous use. [ABSTRACT FROM AUTHOR]

High dielectric permittivity (ε ′ ≈ 2000―6900) was accomplished in Sn4+-doped CaCu 2.95 Mg 0.05 Ti 4 O 12 ceramics while retaining a low loss tangent (tanδ ≈ 0.027―0.075). Further, significant improvements in the nonlinear electrical properties, such as high values of the breakdown electric field (E b ≈ 1.2―1.3 × 104 V cm−1) and nonlinear coefficient (α ≈ 31), were achieved. In addition, the nonlinear electrical parameters significantly improved, which is consistent with the increase in the electrical resistivities of the grains and grain boundaries due to the decrease in the Cu+/Cu2+ ratio. According to our first-principles calculations, the Sn atom at the Ti site prefers to be close to the Mg atom at the Cu site, while the oxygen vacancy prefers to be located at large distances from the Sn and Mg co-dopants. This confirms that the dielectric behavior and the nonlinear electrical properties originate from the interface between the grain and grain boundary. [ABSTRACT FROM AUTHOR]

Sodium-based dual-ion batteries (Na-DIBs) show a promising potential for large-scale energy storage applications due to the merits of environmental friendliness and low cost. However, Na-DIBs are generally subject to poor rate capability and cycling stability for the lack of suitable anodes to accommodate large Na+ ions. Herein, we propose a molecular grafting strategy to in situ synthesize tin pyrophosphate nanodots implanted in N-doped carbon matrix (SnP2O7@N-C), which exhibits a high fraction of active SnP2O7 up to 95.6 wt% and a low content of N-doped carbon (4.4 wt%) as the conductive framework. As a result, this anode delivers a high specific capacity ∼400 mAh g−1 at 0.1 A g−1, excellent rate capability up to 5.0 A g−1 and excellent cycling stability with a capacity retention of 92% after 1200 cycles under a current density of 1.5 A g−1. Further, pairing this anode with an environmentally friendly KS6 graphite cathode yields a SnP2O7@N-C||KS6 Na-DIB, exhibiting an excellent rate capability up to 30 C, good fast-charge/slow-discharge performance and long-term cycling life with a capacity retention of ∼96% after 1000 cycles at 20 C. This study provides a feasible strategy to develop high-performance anodes with high-fraction active materials for Na-based energy storage applications. [ABSTRACT FROM AUTHOR]