Energy Dispersive Spectrum Research Articles

Model-Fitting Weighted Least Squares as an Alternative to Principal Component Analysis for Analyzing Energy-Dispersive X-ray Spectroscopy Spectrum Images.

Spectrum imaging with energy-dispersive X-ray spectroscopy (EDS) has become ubiquitous in material characterization using electron microscopy. Multivariate statistical methods, commonly principal component analysis (PCA), are often used to aid analysis of the resulting multidimensional datasets; PCA can provide denoising prior to further analysis or grouping of pixels into distinct phases with similar signals. However, it is well known that PCA can introduce artifacts at low signal-to-noise ratios. Unfortunately, when evaluating the benefits and risks with PCA, it is often compared only against raw data, where it tends to shine; alternative data analysis methods providing a fair point of comparison are often lacking. Here, we directly compare PCA with a strategy based on (the conceptually and computationally simpler) weighted least squares (WLS). We show that for four representative cases, model fitting of the sum spectrum followed by WLS (mfWLS) consistently outperforms PCA in terms of finding and accurately describing compositional gradients and inclusions and as a preprocessing step to clustering. Additionally, we demonstrate that some common artifacts and biases displayed by PCA are avoided with the mfWLS approach. In summary, mfWLS can provide a superior option to PCA for analysis of EDS spectrum images as the signal is simply and accurately modeled.

Novel Syntheses of Wide-Band Gap Semiconducting CdxZnx−1Co2O4 of Spinel Nanostructure: Characterization and Optical Properties

AbstractCadmium doped zinc cobaltite spinel structure in the form of CdxZnx-1Co2O4 (0 ≤ x ≤ 1) are synthesized by sol-gel method. The energy dispersive X-ray spectra confirm the synthesis of pure ZnCo2O4 and Cd doped samples nanoparticles. Scanning and transmission electron microscopes images of Cd ZnCo2O4 samples show the cubic crystal structure of the nanoparticles. A good crystallinity of the ZnCo2O4 and its dopants samples are indicated by the sharpness and strong peaks of X-ray diffraction patterns. The particle size is independent of the ratio of incorporated Cd into the ZnCo2O4 matrix. The FT-IR transmission spectrum of each Cdx Zn1-xCo2O4 complex shows two strong vibration peaks that are ascribed to the spinel structure’s octahedral and tetrahedral. The absorption spectra reveal three distinct absorption characteristics for Cdx Znx-1Co2O4 peaking at 268, 532 and 778 nm due to the photoexcitation of electrons from O 2p to Co 3d transitions and d-d transition of Co 3d. N2 adsorption–desorption isotherms for Cdx Znx-1Co2O4 indicate are carried out.

Isolation and characterization of biomass waste based bioplasticizer from Eucalyptus leaf: A suitability analysis of biofiller for polymeric composites

Plasticizers improve polymeric materials' properties and processability as additives. Currently, a variety of liquid synthetic plasticizers derived from fossil fuels are available. The environmental unsuitability of these materials could potentially lead to adverse effects on the environment. When we compare solid and liquid plasticizers, we find an infinite variety of liquid plasticizers. As a result, our work focuses on the extraction of plasticizer from plant sources. Accordingly, the plasticizer is extracted from eucalyptus leaves via solvent purification and surface catalysis. Research was conducted utilizing X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Ultraviolet (UV) visible spectroscopy to determine the characteristics of plasticizer. The scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analysis are used to analyze the surface morphology of the isolated plasticizer. The plasticizer's UV examination reveals active absorption at 375.21 nm. The plasticizer was determined to have a lower density of 0.941 g/cm3. The plasticizer that was extracted had a low solubility in water and organic solvents while possessing an estimated molecular weight of 340. The glass transition temperature of plasticizer was also examined using differential scanning electron microscopy analysis and found to be 64.17°C. The crystallinity index and size were found to be 34.08% and 28.57 nm, respectively. The characteristic features obtained were well-suited for use as filler in polymer composite materials.

Synthesis of Copper(I) Oxide Thin Film Through Potentiostatic Electrodeposition as an Antioxidant Film

Research on metal-based nanoparticles, such as silver, gold, and copper(I) oxide (Cu2O), has drawn considerable attention due to their potential applications in catalysis, antioxidants, antimicrobials, and anticancer fields. In this study, we successfully deposited Cu2O antioxidant films on indium tin oxide substrates through potentiostatic electrodeposition. The X-ray diffraction characterization revealed distinct peaks at 2θ value of 36.32°, 42.21°, and 61.30°, indicating the crystal structure of Cu2O thin film. The scanning electron microscopy image showed the three-sided pyramid morphology of Cu2O particles with average size of 316.18 nm. The energy dispersive X-ray spectrum confirmed the purity of the thin film, which is composed only of Cu and O elements without any impurities. The photoelectrochemical showed that the deposited Cu2O has a maximum photocurrent density of 8.37 mA/cm² under visible light irradiation and 1.40 mA/cm² without irradiation. In addition, this study also found that the highest inhibition values of DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals were observed when ascorbic acid was added.

In Situ Transformed CoOOH@Co3S4 Heterostructured Catalyst for Highly Efficient Catalytic OER Application.

The deprived electrochemical kinetics of the oxygen evolution reaction (OER) catalyst is the prime bottleneck and remains the major obstacle in the water electrolysis processes. Herein, a facile hydrothermal technique was implemented to form a freestanding polyhedron-like Co3O4 on the microporous architecture of Ni foam, its reaction kinetics enhanced through sulfide counterpart transformation in the presence of Na2S, and their catalytic OER performances comparatively investigated in 1 M KOH medium. The formed Co3S4 catalyst shows outstanding catalytic OER activity at a current density of 100 mA cm-2 by achieving a relatively low overpotential of 292 mV compared to the pure Co3O4 catalyst and the commercial IrO2 catalyst. This enhancement results from the improved active centers and conductivity, which boost the intrinsic reaction kinetics. Further, the optimized Co3S4 catalyst exhibits admirable prolonged durability up to 72 h at varied current rates with insignificant selectivity decay. The energy dispersive X-ray spectroscopy (EDX) and Raman spectra measured after the prolonged OER stability test reveal a partial transformation of the active catalyst into an oxyhydroxide phase (i.e., CoOOH@Co3S4), which acts as an active catalyst phase during the electrolysis process.

Zinc oxide-based sensor prepared by modified sol–gel route for detection of low concentrations of ethanol, methanol, acetone, and formaldehyde

Abstract We4 4 We received the acceptance date as 26 September 2024. Could you please update it to reflect this exact date for our project, instead of 1 October 2024? This is very important for our project funding. successfully synthesized zinc oxide (ZnO) nanoparticles using the sol–gel method, followed by their application onto alumina substrates for sensor testing. Comprehensive characterization of the nanomaterials was carried out utilizing XRD, SEM, TEM, UV–VIS-IR, and Photoluminescence (PL) techniques. The nanoparticles displayed a hexagonal wurtzite crystal structure, typical of ZnO. UV–Vis-IR spectroscopy revealed significant absorption in the UV region, with the band gap energy calculated to be 3.22 eV. PL spectra indicated the presence of various defects, such as oxygen vacancies and zinc interstitials, within the ZnO structure. SEM analysis of the deposited film surface showed spherical agglomerates, confirming the nanoscale dimensions, while energy-dispersive x-ray spectroscopy spectra affirmed the high purity of the ZnO films, rich in Zn and O elements. Sensor tests demonstrated the ZnO sensor’s high sensitivity to low concentrations of volatile organic compounds such as ethanol, formaldehyde, methanol, and acetone. Notably, at an operational temperature of 300 °C, the sensor exhibited a remarkable response to 5 ppm of each gas, with the following response and response/recovery times: for methanol, 11.47 and 36 s/57 s; for acetone, 11.54 and 25 s/52 s; for formaldehyde, 0.79 and 53 s/58 s; and for ethanol, 3.88 and 9 s/59 s.

Development of hydrophilic multilayer structures for energy saving window applications using sol-gel spin coating

This study is centered on analyzing the microstructural and optical reflectivity properties of multilayers composed of dielectric titania and silica. The goal is to investigate their potential application as energy-efficient windows on glass surfaces in different modern building projects. Nevertheless, the creation of these coatings can be quite expensive due to their complex structure. This study focuses on the development of a cost-effective method to produce a multilayer structure made of titania and silica. This structure has the remarkable ability to reflect approximately 100 % of UV light and 70 % of infrared light, all achieved with just three layers. The X-ray diffraction (XRD) analysis was conducted to examine the crystallinity of the coatings. The results indicated the presence of an anatase phase, as evidenced by the Bragg angle of 25O. Empirical support was obtained through the use of Fourier transform infrared spectroscopy (FTIR), which revealed the presence of functional bonds at specific wavenumbers. Titania and silica were identified at wave numbers of 596 cm−1 and 1246 cm−1, respectively. The FTIR investigation was further supported by energy dispersive spectrum analysis (EDAX), which verified the existence of titania and silica in the multilayer structure. Through the use of field emission scanning electron microscopy (FESEM), the analysis of the multilayer structure unveiled the existence of layers composed of titania, silica, and titania. These layers were found to have thicknesses of approximately 286 nm, 315 nm, and 222 nm, respectively. The coatings were analyzed for reflectance using a UV–VIS-NIR spectrophotometer, which showed a full reflection of 100 % in the far ultraviolet range and a reflection of 70 % in the infrared region. Furthermore, the analysis of the coatings’ wetting behavior with a contact angle meter revealed their hydrophilic nature, suggesting their potential use in self-cleaning applications.

Study of structural, morphological and optical properties of flash evaporated cadmium sulphide thin films

Cadmium sulphide thin films were successfully synthesized by the flash evaporation method under vacuum, then annealed at various temperatures. X-Ray Diffraction patterns showed the formation of the hexagonal wurtzite phase. Structural properties of this most stable phase remain approximately the same at all investigated temperatures. Scanning Electronic Microscopy showed the formation of granular films. The Energy Dispersive X-ray spectra revealed the possible formation of stoichiometric compounds. The obtained UV–Vis spectra revealed that the prepared films exhibit a moderate direct band gap with high transmittance in the visible range. Detailed interpretation of the structural, optical, and optoelectronic findings revealed that annealed CdS thin films hold promising potential for the fabrication of the next generation of the modern optoelectronic devices. Cadmium sulphide thin films were successfully synthesized by the flash evaporation method under vacuum, then annealed at various temperatures. X-Ray Diffraction patterns showed the formation of the hexagonal wurtzite phase for all temperatures with almost the same structural properties. UV–vis spectra revealed that the prepared films exhibit a moderate direct band gap with high transmittance in the visible range, which reinforces the usefulness of these films for photovoltaic and photocatalytique applications. Scanning Electronic Microscopy shows the formation of granular films, while the Energy Dispersive X-ray spectra revealed the possible formation of stoichiometric compounds.

The effects of pH regulators on the flotation separation of sphalerite and dolomite and their interaction mechanism

pH regulators play a key role in mineral flotation. In the study, the effects of CaO, Na2CO3 and NaOH on the flotation separation of sphalerite and dolomite were investigated, and the interaction mechanisms were analyzed by flotation tests of mixed minerals, scanning electron microscope (SEM) and energy dispersion spectrum (EDS), turbidity, Zeta potential and the extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) theory. The results indicated that Na2CO3 was favorable for flotation separation of sphalerite and dolomite, but NaOH had a negligible effect. CaO improved the flotation recovery of MgO to a maximum value of 9.29%, but it was unfavorable to the enriched sphalerite. SEM-EDS results revealed that dolomite was adsorbed on the sphalerite surface in the three systems, but the amounts of dolomite attached in the CaO system was higher than those of the other two systems. Turbidity tests indicated that the turbidity in the CaO system was less than that in Na2CO3 and NaOH systems. The sphalerite surface was negatively charged regardless of the pH regulators. Na2CO3 and NaOH hardly affected the surface potentials of dolomite. However, CaO changed the surface potential of dolomite from negative value to positive value under high alkaline condition. EDLVO theoretical calculations revealed that the electrostatic forces in CaO system were stronger than that in Na2CO3 and NaOH systems, leading to the slime coating.

Impact of sol-gel synthesized α-aluminium oxide nanoparticles for the enhancement of transformer oil insulation properties

Transformers require advanced insulating materials that outperform mineral oil in terms of cooling, insulation effectiveness, eco-friendliness, and operational efficiency in extreme operational and weather conditions. As a result, emphasis has shifted to renewable and ecologically friendly materials. This change in emphasis is motivated by worries about the environment, fuel shortages, and the disposal of waste oil. Transformers have historically employed solid insulators like paper and pressboard as well as mineral or synthetic oil. However, the development of ecologically friendly insulating materials has been spurred by new environmental regulations as well as economic benefits. This research investigates the use of sol-gel synthesized aluminium oxide (Al2O3) nanoparticles to improve the insulation properties of host transformer oil. The synthesized aluminium nanoparticles were characterized with X-ray diffractometer (XRD) and found rhombohedral structure, whose chemical composition was studied by energy dispersive X-ray spectrum (EDAX). Investigation using Fourier transform infrared spectroscopy (FTIR) also revealed the production of AlOOH and hydroxyl vibrational bands at wavenumbers of 690 and 2976 cm−1, respectively. Studies using field emission scanning electron microscopy (FESEM) showed that the nanoparticles are spherical in form and have a diameter of around 38 nm. Additionally, the incorporation of α-aluminium oxide nanoparticles into the host oil showed an improvement in the breakdown voltage and suggested a possible use for better transformer oil insulation.

Ag modified ZnO nanoflower gas sensitive sensor for selective detection of n-butanol

Ag modified ZnO nanoflowers were successfully prepared by sunlight induced solvent reduction method. The samples were characterized by x-ray diffractometer, field emission scanning electron microscope, transmission electron microscope and energy dispersive x-ray spectrum, and the results confirmed the presence of Ag nanoparticles on the ZnO nanoflower. The gas sensing performance of the materials was studied at different operating temperatures and different n-butanol concentrations. The results showed that the Ag modified ZnO nanoflower sensor responded to 50 ppm n-butanol up to 147.17 at 280 °C, and the Ag modified ZnO nanoflower sensor exhibited excellent repeatability, stability and response recovery time. In addition, different target gases were employed for the selectivity study of the Ag modified ZnO nanoflower. It can be found that the Ag modified ZnO nanoflower had good selectivity for n-butanol. The improved response of the Ag modified ZnO nanoflower sensor was attributed to the catalytic effect of Ag nanoparticles. The results indicate that the Ag modified ZnO nanoflower will become a very promising sensing material for n-butanol gas detection.

Collapse of G+/G- bands, modification of Breit–Wigner–Fano signals and structural amorphization in single wall carbon nanotube networks under great excess of sulfur

The identification of superconductivity and ferromagnetic to superconductive transitions in sulfur-modified carbons has recently attracted an important attention. Additional work is however needed to better understand the structural modification of the graphitic interfaces in presence of sulfur. Here we report on an advanced methodology which involves soaking of large amounts (in the order of 500 mg) of sulfur through several annealing cycles into bundles comprising of hollow single-wall/few-wall carbon nanotubes (SWCNTs). TEM, HRTEM, XRD and Raman spectroscopy characterization analyses reveal the presence of structural amorphization of the SWCNTs, with dramatic impact on the intensity of the G+ and a progressive vanishing of the G- signal-contribution. We demonstrate the presence of high sulfur content by employing both point and mapping energy dispersive X-rays (EDX maps) acquisitions, with high local quantities of sulfur in the order of 16 %. Interestingly, a complex variation in the contribution of the Breit-Wigner-Fano (BWF) band, with appearance of extra D, G+ and C-S band-contributions, is revealed by deconvolution-analyses. The appearance of these structural features is a clear indicator of structural amorphization of the CNTs, with consequential formation of C-S hybrid structures, which we analyze systematically with the aid of energy dispersive X-ray spectrum mapping and Raman point/mapping spectroscopy approaches.

Cost-Effective Synthesis of MXene Cadmium Sulfide (CdS) for Heavy Metal Removal.

Background Environmental contamination resulting from the release of untreated industrial wastewater has emerged as a critical worldwide issue. These effluents frequently have high levels of heavy metals and antibiotics, which are bad for aquatic ecosystems and human health. Oftentimes, conventional wastewater treatment techniques fall short of effectively eliminating these pollutants. Innovative materials that may efficiently absorb or break down contaminants from contaminated water sources are, therefore, desperately needed. Hydrothermally produced MXene cadmium sulfide (CdS) composites have shown great promise as an adsorbent material because of their special qualities, which include high surface area, chemical stability, and customizable surface functions that improve their adsorption capacity for heavy metals and antibiotics alike. Aim The aim of this study is to produce MXene-CdS nanoparticles in a cost-effective method for the simultaneous removal of heavy metals from aqueous contaminants for water pollution control. Methods and materials MXenes were synthesized by selectively etching Ti3AlC2 MAX-phase ceramics using aqueous HF. CdS nanoparticles were synthesized separately and integrated with MXenes via a hydrothermal process. The resulting MXene CdS nanocomposites were characterized using scanning electron microscopy (SEM) for morphology, energy dispersion spectrum (EDS) for elemental composition, X-ray diffraction(XRD) study for phase identification, and removal of heavy metals viaMXene CdS. Results Consistent distribution of CdS nanoparticles on the MXene surface and the creation of MXene CdS nanomembranes with a well-defined shape were observed by SEM analysis. Ti, C, Cd, and S elements, indiciaries of a successful composite formation, were confirmed to be present by EDS. The crystalline structure of both the MXene and CdS phases was confirmed by the distinctive peaks seen in the XRD patterns. MXene-CdS composites facilitate the effective removal of chromium ions from contaminated water. The excellent hydrophilicity of the produced nanomembrane allowed for effective interaction with watery contaminants. Conclusion This study showcases the successful synthesis and characterization of MXene-CdS nanocomposites for environmental remediation, particularly in removing toxic metals like chromium from industrial effluents. SEM analysis confirmed the uniform distribution of CdS nanoparticles on the MXene surface, while elemental composition validated their integration. XRD analysis confirmed the crystalline structures of both components. The nanocomposite exhibited excellent hydrophilicity, enhancing the efficient adsorption of heavy metals. Its large surface area and chemical stability contribute to high adsorption efficiency, making it ideal for wastewater treatment. The scalable synthesis process supports practical applications. This research highlights MXene-CdS nanocomposites as a cost-effective, sustainable solution for water pollution control.

Differential mineral diagenetic evolution of lacustrine shale: Implications for CO2 storage

Understanding the differential diagenetic evolution of different lithofacies is essential for assessing the spatial development of shale reservoirs. These insights are crucial in predicting sealing integrity and storage capacity for sequestered CO2. In this study, we examined seven wells from the Cretaceous Qingshankou Formation in the Songliao Basin, China, with vitrinite reflectance (Ro) values ranging from 0.60 % to 1.62 %. Thin section-based petrographic observations, coupled with QEMSCAN analysis, were used to classify the different lithofacies. X-ray diffraction (XRD) analysis of clay minerals, field emission scanning electron microscope (FE-SEM), and energy-dispersive spectrum (EDS) analyses were employed to analyze the mineral textures, pore types, and diagenetic pathways. The results showed that early diagenetic mineral phases include calcite cement (1st phase), framboidal and microcrystalline pyrite, ferroan and non-ferroan dolomite. Intermediate diagenetic mineral phases were marked by illitization of smectite, chlorite formed by chloritization of smectite and alteration of K-feldspar, and the formation of authigenic albite and quartz, calcite cement (2nd phase) and ankerite. Given the higher potential reaction rate of CO2-fluid‑carbonate systems, we propose that the lithofacies dominated by carbonate minerals are not effective for CO2 storage, even in short-term. In contrast, lithofacies rich in feldspar and clay minerals are likely to be more effective for long-term CO2 storage.

Comprehensive investigation of zinc and tin-based metal oxides for advanced electrochemical detection of organophosphate pesticides

Different metal oxide (MO) nanomaterials, such as ZnO, SnO2, and nanocomposites of ZnO:SnO2 with various ratios of (1:9), (2:8), and (3:7) were prepared and coated on glassy carbon electrode (GCE). These MOs were tested as sensing material for organophosphate (OP) pesticides detection. Among all MOs, ZnO:SnO2 (1:9) coated GCE increases redox peak current at different buffer solutions with varying pH compared to bare GCE. Moreover, among these pH values, ZnO:SnO2 (1:9) coated GCE significantly enhanced the redox peak at pH 6.2, emphasizing optimal electrochemical conditions for the given pesticides. The morphological, elemental composition, metal ions-functional group interation, and crystallinity of different MO nanocomposites were examined using field-emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectrum (EDX), and X-ray diffraction (XRD), respectively. The modified GCE with ZnO:SnO2 (1:9) showed an excellent performance during the electrochemial sensing of the diazinon (DiZn) pesticide. Therefore, detailed study was carried out for the sensing of DiZn. Furthermore, the electrochemical behavior of the ZnO:SnO2 (1:9) coated GCE was evaluated using cyclic voltammetry (CV) with 0.5 mL (5 mM) potassium ferrocyanide, resulting in a pronounced increase in anodic and cathodic peak potentials (Epa = 0.423 V, Epc = 0.1945 V) and currents (Ipa = 9.867 × 10-5 mA, Ipc = -7.993 × 10-5 mA). In addition, electrochemical impedance spectroscopy (EIS) demonstrated a reduction in charge transfer resistance for the coated ZnO:SnO2 (1:9) GCE. Differential pulse voltammetry (DPV) further showed a linear relationship between current and pesticide concentration, with a high correlation coefficient (R2 = 0.996), low limit of detection (LOD = 0.0133 mM) and low limit of quantification (LOQ = 0.0405 mM). Real samples, including tap and seawater, were analyzed to validate the method’s applicability. Additionally, chronoamperometry with a step potential of 1.2 V indicated high sensitivity for DiZn detection, with a sensitivity of 0.23 mA mM−1 cm−2. Finally, the stability of the ZnO:SnO2 (1:9) coated GCE was confirmed through recyclability tests over three cycles using CV and DPV techniques, ensuring its robustness for practical applications in pesticide detection.

Comparative investigation of composition, microstructure and property influences on electrocatalysis of two representative cathodes: BaCo0.4Fe0.4Zr0.1Y0.1O3-δ versus Ba0.5Sr0.5Co0.8Fe0.2O3-δ

BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) and Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) perovskites are two representative high-performance cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Here, symmetric cell tests demonstrate that polarization resistance values of BCFZY cathode are only 0.21–0.29 times those of BSCF cathode at 740–660 °C, and 0.21–0.26 times those of BSCF cathode at the oxygen partial pressures of 1.00–0.10 atm. Distribution of relaxation times (DRT) is applied to detect individual electrode processes overlapped in impedance spectra, which finds that the dominant processes of oxygen dissociation, subsequent species transfer and reduction on BCFZY cathode are superior to those of BSCF cathode. By temperature-programmed desorption of oxygen (O2-TPD), thermal expansion coefficient (TEC) measurements, scanning electron micrograph (SEM) and energy dispersive spectra measurements, the strong oxygen combination ability with higher activation energy of oxygen desorption (Ed = 84 kJ/mol), peculiar surface state with evident nano-particle structure, more matchable TEC (19.0 × 10-6 K−1) and excellent interfacial connection with the electrolyte are observed on BCFZY cathode to account for its distinctive catalysis, as compared to BSCF cathode (Ed = 68 kJ/mol, TEC = 24.2 × 10-6 K−1).

Aluminum antimony alloy overlayers synthesized using the electrodeposition method: investigation of structural, optical, electrical properties, and DFT calculation

Abstract This paper presents the synthesis of aluminum antimony (Al–Sb) alloy overlayers using an electrodeposition method for application in optoelectronic devices with various applied constant voltages (2, 4, 6, 8, and 10 V) controlled by a DC power supply. The corresponding energy dispersive x-ray spectroscope spectra show that elements including Al, Sb, and Cl were detected in the layers under all conditions of the applied voltage. The structural properties of the formulated compound layers were studied for their structural properties through x-ray diffraction patterns, and all the diffraction peaks exhibited a cubic phase structure. The Al–Sb alloy overlayers were incorporated with nanoparticles and had crystallite sizes ranging from ∼55 to 282 nm. The average transmittance T(λ) values in the visible to near-infrared region were ∼28.36%, 17.64%, 14.07%, 7.83%, and 5.84%, while the average reflectance R(λ) values were ∼3.80%, 1.69%, 1.30%, 0.47%, and 0.21% for applied voltages of 2–10 V, respectively. The energy band gap (E g) existing in the overlayers was determined using Tauc’s plot with the Kubelka–Munk function and it was inferred to be between 1.90 eV and 2.72 eV. The dispersion constants and energies of the prepared samples were also investigated. The 2 V applied voltage-treated Al–Sb alloy overlayers showed the highest average χ(1), χ ( 3 ) , and n 2 values of 0.088, 1.680 × 10−14 esu., and 4.082 × 10−13 esu., respectively. In addition, the resistance at various absolute temperatures was also recorded for the activation energy (E AC) values of the Al–Sb alloy overlayers with applied voltages of 2–10 V. Finally, ab initio calculations based on density functional theory were performed to support the experimental report of the Al–Sb systems. It was found that the calculated lattice constants are in good agreement with the experimental results, and a wider photoabsorption range performance for Al–Sb phase I in the axis of energy seems to be suitable for application as an optical device.

Preparation and Photodegradation of TiO2 Thin Films on the Inner Wall of Quartz Tubes.

Titanium dioxide thin films on the inner wall of quartz tubes were prepared in situ by the sol-gel method. Meanwhile, copper and cerium were loaded onto the surface of the titanium dioxide thin films to enhance photocatalytic activity and broaden the range of light absorption. X-ray diffractometer, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrum, N2 gas adsorption, UV diffuse reflectance spectroscopy, electron paramagnetic resonance, photoluminescene spectroscopy, and so on were used to characterize the structure, morphology, chemical composition, and optical properties of the prepared photocatalyst. Methylene blue (MB) was used as a simulated organic pollutant to study the photocatalytic performance of the photocatalyst, which was a translucent, structurally stable, and reusable high-efficiency photocatalytic catalyst. Under UV lamp irradiation, the MB photodegradation efficiency was 94.5%, which reached 91.2% after multiple cycles.

Effect of 10 MeV electron irradiation on structural and magnetic properties of Ti- and Al- substituted strontium hexaferrite SrFe11.3Ti0.4Al0.3O19

The irradiation stability of Ti- and Al-substituted SrFe11.3Ti0.4Al0.3O19 strontium hexaferrite to 10 MeV electron irradiation with the fluences of 1014 and 2·1017 cm−2 was investigated using various characterization techniques such as scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectrum microanalysis, atomic force microscopy, Raman spectroscopy, vibrating sample magnetometry and magnetic force microscopy. Notable changes in lattice vibrations, magnetic domain microstructure and magnetization behavior were obtained after the electron irradiation with the fluence of 2·1017 cm−2. Phonon hardening observed by Raman spectroscopy confirms the increasing disorder in crystalline structure and the presence of spin-phonon coupling in the samples after electron irradiation with the fluence 2·1017 cm−2. It was found that the strongest spin-phonon interactions correspond to A1g vibration modes at trigonal bipyramidal 2b, 2a octahedral, 4f1 tetrahedral sites and E1g mode at 4f2 octahedral site in electron-irradiated SrFe11.3Ti0.4Al0.3O19 hexaferrite, while the most radiation-resistant phonon mode is A1g vibration of the Fe–O bonds at the 4f2 octahedral site. No significant change was observed in magnetic saturation magnitude after electron irradiation. The increase in coercivity and significant decrease of magnitude of the dM/dH derivative of magnetization curves with increasing radiation fluence is attributed to the increase in uniaxial magnetic-crystalline anisotropy. It is found that the fractal dimension of hierarchical magnetic domain structure in SrFe11.3Ti0.4Al0.3O19 continuously decreases with increasing fluence of 10 MeV electron irradiation, which can be caused by the distortion in uniaxial magnetocrystalline anisotropy and irradiation-induced defects.

High-quality thickness-tunable InAs nanowire crosses grown by molecular-beam epitaxy

InAs nanowire crosses show great potential applications in detection and braiding of Majorana zero modes. Controlled growth of high-quality and diameter tunable InAs nanowire crosses is fundamental for these applications. However, it is still difficult to freely and conveniently adjust the diameter of the free-standing InAs nanowire crosses grown by the conventional growth methods. Here, we report a new technique to realize the growth of high-quality thickness-tunable InAs nanowire crosses by molecular-beam epitaxy. GaAs nanowire crosses were firstly grown on the Si (100) substrates spontaneously by merging the <111>-oriented GaAs nanowires. InAs nanowire crosses were then obtained by in situ growth of InAs shells on the facets of GaAs nanowire cross cores. Detailed scanning and transmission electron microscopic observations and energy dispersive spectrum analyses confirm that the InAs nanowire crosses grown by this manner have continuous and smooth morphology and they are high-quality zinc-blende crystals. More importantly, the InAs shell is grown with the vapor-solid growth mechanism and the thickness of the InAs nanowire crosses can be tuned by varying the InAs shell growth time. Our work provides a valuable method for the controlled growth of thickness-tunable semiconductor nanowire crosses.