X-ray Diffraction Results Research Articles

Iron transformation and hydroxyl radical production during mixing surface water and groundwater in the riparian zone: Effects of bicarbonate and surface water-groundwater ratio

The interaction between surface water and groundwater in the riparian zone significantly influences iron (Fe) transformation. This study characterized the Fe mineral composition of sediments collected from the riparian zones upstream and downstream of the Xinglong Dam of Han River, China. The coexistence of divalent (Fe–CO3) and Fe(III) minerals in the sediments suggested varying redox conditions of the riparian zone. Furthermore, the transformation processes of dissolved Fe(II) under different bicarbonate concentrations and surface water-groundwater ratios during the interaction between surface water and groundwater were investigated by laboratory batch experiments to understand the formation of Fe–CO3 and Fe(III) minerals in the riparian zone. The results demonstrated that elevated bicarbonate concentrations (0–20 mM) and surface water ratios promoted the transformation rate and amount of dissolved Fe(II) to solids. The predominant minerals of the formed solid were lepidocrocite, goethite, and Fe–CO3, according to the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. The rising bicarbonate concentration facilitated Fe–CO3 synthesis. The Fe(III) mineral (goethite) was more likely to develop when dissolved oxygen (DO) and bicarbonate concentrations were high. The generated hydroxyl radical (•OH) during dissolved Fe(II) oxidation was also increased with elevated HCO3− concentration and surface water ratio, indicating higher oxidative potential in the riparian zone with higher bicarbonate and surface water ratio. These findings offer insights into the Fe transformation in redox-fluctuating zones.

Impact of Electronic Waste Glass on the Properties of Cementitious Materials

The article analyses the impact of two different types of dispersive glass on cement hydration and compressive strength at 7 and 28 days. The study employed dispersive glass from various LCDs (TV sets, computer monitors, smart phones), characterised by a composition of approximately 8% SrO, and dispersive glass from washing machines, which consists mainly of SiO2, Na2O, and CaO. The chemical composition and particle-size distribution of different types of dispersive glass were analysed. The study compares the effect of electronic waste glass on cement hydration by evaluating the amount and rate of heat released during the process. In addition, the results of X-ray diffraction (XRD), thermogravimetric analysis (TG), and scanning electron microscopy (SEM) are provided. Different types of glass were determined to have a similar effect on the physical and mechanical properties as well as the mineral composition of cementitious samples: density and UPV decrease up to 6% and compressive strength decreases by about 30%, when 5–20% of cement was replaced by glass waste. However, more prominent differences were observed in the workability of the mixtures: the waste glass from home appliances increased the spread by up to 25%, while the waste glass from electronic devices decreased the spread compared to the reference sample by approximately 20%. The mixtures modified with the waste glass of electronic devices had a higher degree of early hydration (96%) due to the higher water absorption of the mixtures compared to the waste glass of home appliances (88%).

Designing reduced graphene oxide decorated Ni doped δ-MnO2 nanocomposites for supercapacitor applications

Reduced Graphene Oxide (rGO) decorated δ-MnO2 and Ni-doped δ-MnO2 samples have been synthesized by a microwave-assisted co-precipitation technique which is low cost, simple and fast reaction method. The structural and morphological properties of synthesized samples have been characterized using x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). XRD result indicates that all samples have monoclinic crystal structure with δ phase of MnO2. The morphologies of MnO2 transformed into perforated porous nanoflakes with Ni doping and rGO composition in MnO2. AFM images confirmed that surface roughness for 3 % Ni-doped MnO2 samples is higher due to the chemical adsorption of samples. Raman spectroscopy results show the presence of vibrational and Raman active modes of MnO2.X-ray photoelectronic spectroscopy revealed the presence of mixed valencies of Mn such as Mn2+, Mn3+, and Mn4+ in prepared nanocomposites while Ni shows 2+ valency. The specific capacitance (Cs) of pure δ -MnO2 samples were 68 Fg-1 and rGO decorated 3 % Ni-doped MnO2 composition 694 Fg-1 at 10 mVs−1 respectively. EIS data of the rGO decorated Ni-doped MnO2 composition samples confirm that the porous nanoflake-shaped rGO decorated 3 % Ni-doped MnO2 composite sample has a low resistance value among all samples. These results reveal that rGO-decorated 3 % Ni-doped MnO2 nanoflakes should be a promising material for designing and fabricating the electrode material for high-performance supercapacitors.

Size-Dependent High-Pressure Behavior of Pure and Eu3+-Doped Y2O3 Nanoparticles: Insights from Experimental and Theoretical Investigations.

We report a joint high-pressure experimental and theoretical study of the structural, vibrational, and photoluminescent properties of pure and Eu3+-doped cubic Y2O3 nanoparticles with two very different average particle sizes. We compare the results of synchrotron X-ray diffraction, Raman scattering, and photoluminescence measurements in nanoparticles with ab initio density-functional simulations in bulk material with the aim to understand the influence of the average particle size on the properties of pure and doped Y2O3 nanoparticles under compression. We observe that the high-pressure phase behavior of Y2O3 nanoparticles depends on the average particle size, but in a different way to that previously reported. Nanoparticles with an average particle size of ~37 nm show the same pressure-induced phase transition sequence on upstroke and downstroke as the bulk sample; however, nanoparticles with an average particle size of ~6 nm undergo an irreversible pressure-induced amorphization above 16 GPa that is completed above 24 GPa. On downstroke, 6 nm nanoparticles likely consist of an amorphous phase.

Structure and piezochromism of chrysene at high pressures

Fluorescence materials have attracted great attention in the last decades because of their modulable fluorescence properties and broad applications. Molecular packing is one of the most important factors that determines organic molecular piezochromic fluorescence behavior. Herein, we systematically investigated the fluorescence, vibrational, and structural properties of chrysene up to 20 GPa by using multiple experimental techniques and ab-initio calculations. We find the obvious color-changing with increasing pressure. Meanwhile, the phase transition at a pressure of about 6.6 GPa has been identified from both the frequency shifts and the changes in intensity of the Raman modes. However, the structure of chrysene at ambient pressure remains stable to at least P∼20.2 GPa from both experimental and theoretical x-ray diffraction results. Further structural analysis indicates that the angle between two molecular planes decreases with pressure, resulting in the packing alteration. The combined results from the experiments and computations demonstrated that the observed phase transition at 6.6 GPa is probably a result of the change of molecular packing. Furthermore, the intermolecular interactions have changed correspondingly due to the change of the molecular packing, which results in the color-changing of chrysene under pressure. These results provide further evidence that the intermolecular interactions play the important role in tuning the photo-physical properties, and this work will contribute to understanding the relationship between molecular packing and piezochromism in fluorescence materials.

A High-Performance Supercapacitor Based on Hierarchical Template-Free Ni/SnO2 Nanostructures via Hydrothermal Method.

Novel flake-like Ni1-xSnxO2 particles were successfully prepared by template-free hydrothermal synthesis. The prepared samples were investigated for their properties by different characterization techniques. Scanning micrographs showed that the obtained particles consisted of nanoflakes. The X-ray diffraction results of the Ni1-xSnxO2 revealed the formation of mixed-phase Ni/SnO2 having the typical tetragonal structure of SnO2, and the cubic structure of Ni in a nanocrystalline nature. The doping with Ni had a certain influence on the host's lattice structure of SnO2 at different doping concentrations. Confirmation of the functional groups and the elements in the nanomaterials was accomplished using FTIR and EDS analyses. The electrochemical performance analysis of the prepared nanomaterials were carried out with the help of the CV, GCD, and EIS techniques. The specific capacitance of the synthesized nanomaterials with different concentrations of Ni dopant in SnO2 was analyzed at different scanning rates. Interestingly, a 5% Ni-doped SnO2 nanocomposite exhibited a maximum specific capacitance of 841.85 F g-1 at 5 mV s-1 in a 6 M KOH electrolyte. Further, to boost the electrochemical performance, a redox additive electrolyte was utilized, which exhibited a maximum specific capacitance of 2130.33 at 5 mV s-1 and an excellent capacitance retention of 93.22% after 10,000 GCD cycles. These excellent electrochemical characteristics suggest that the Ni/SnO2 nanocomposite could be utilized as an electrode material for high-performance supercapacitors.

Growth and impact of intrinsic interlayers in high temperature vapor phase epitaxy of GaN

Structural quality of GaN layers grown on foreign substrates is usually improved by applying masks or interlayers, which interact with the crystal structure defects, mainly with threading dislocations, and consequently reduce their density. In this work, GaN interlayers with intrinsic defect structures were employed as barriers impeding the propagation of threading dislocations. The GaN samples were produced in a multistage deposition process by high-temperature vapor phase epitaxy (HTVPE). They consisted of GaN seed layers deposited on 15 × 15 mm2 (001)-oriented sapphire substrates, structured GaN interlayers and GaN top layers. The structuring of the interlayers was facilitated by changing the substrate temperature and the V/III ratio during the growth. The optical and scanning electron microscopies revealed that the structured interlayers contain pyramidal facets, vertical trenches and elongated voids. The results of X-ray diffraction and Raman spectroscopy have shown that these microstructure features are able to reduce the density of threading dislocations in the top layer and the tensile residual stress that develops in the top layer during the deposition process. These results demonstrate the potential of the intrinsic interlayer concept for the in-line defect and stress engineering in HTVPE GaN layer stacks.

Luminescent metal-organic framework sensor for detection of biomarker 2-thiothiazolidine-4-carboxylic acid

Using terephthalic acid (BDC) as the organic ligand and zirconium chloride (ZrCl4) as the metal source, a lanthanide metal-organic framework (Tb/Zr-UiO-66) with excellent luminescence properties was successfully prepared by introducing the lanthanide ion Tb3+in situ through a simple one-pot hydrothermal reaction, which was designed as an optical biosensor for 2-thiothiazolidine-4-carboxylic acid (TTCA), the urinary biomarker of human exposure to carbon disulfide (CS2). The fabricated Tb/Zr-UiO-66 exhibits high chemical and luminescent stability, making it competent for recognizing TTCA in aqueous environments. Significantly, its luminescence intensity change shows a good linearity relationship with the concentration of TTCA in the range of 0–110 µM, with a limit of detection (LOD) as low as 0.14 µM. Meanwhile, this sensor exhibits good selectivity and anti-interference ability towards TTCA among the various coexisting components in urine (Na+, K+, NH4+, SO42−, Cl −, creatine, creatinine, glucose, urea, etc.), and can quickly respond to TTCA within 2 min. The analysis results of powder X-ray diffraction (PXRD), fluorescence lifetime and ultraviolet–visible (UV–vis) spectrum demonstrate that the sensing mechanism can be ascribed to the competition absorption effect between TCAA and Tb/Zr-UiO-66. This biosensor with simple synthesis, stable framework, high sensitivity and selectivity, and rapid response has potential to become a powerful tool for diagnosing diseases associated with CS2 exposure.

Investigation of the effects of glycerol addition as a catalyst on the morphology and structural properties of Gd/Er co-doped hydroxyapatite

This study investigates the effects of increasing amounts of glycerol, ranging from 0 to 16 mL, used in the synthesis on the structural properties of Gd and Er-based hydroxyapatite (HAp). The samples were prepared via a wet chemical route, and their characterizations were carried out using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy. The XRD and FTIR results confirmed the formation of the HAp phase in the samples. It was observed that the addition of glycerol at different amounts in the synthesis affected the crystallinity degree and crystallite size. The morphology was almost not affected by the glycerol content as used.

Effect of Lattice Disorder on Exciton Dynamics in Copper-Doped InP/ZnSexS1-x Core/Shell Quantum Dots.

InP/ZnSexS1-x core/shell quantum dots (QDs) with varying Cu concentrations were synthesized by a one-pot hot-injection method. X-ray diffraction and high-resolution transmission electron microscopy results indicate that Cu doping did not alter the crystal structure or particle size of the QDs. The optical shifts in UV-visible absorption and photoluminescence (PL) suggest changes in the electronic structure and induction of lattice disorder due to Cu doping. Ultrafast transient absorption spectroscopy (TAS) reveled that a higher Cu-doping level leads to faster charge carrier recombination, likely due to increased nonradiative decay from defect states. Time-resolved PL (TRPL) studies show longer average lifetimes of charge carriers with increased Cu doping. These findings informed the development of a kinetic model to better understand how Cu-induced disorder affects charge carrier dynamics in the QDs, which is important for emerging applications of Cu-doped InP/ZnSexS1-x QDs in optoelectronics.

Optimizing clozapine-loaded nanostructured lipid carriers through central composite design for enhance bioavailability in antipsychotic therapy

Clozapine (CLZ), a tricyclic dibenzodiazepine antipsychotic drug employed for the treatment of Schizophrenia. However, CLZ's significant first-pass effect, poor water solubility, and low oral bioavailability (27%) limit its potential for therapeutic use. The present investigation aimed to prepare CLZ-loaded nanostructured lipid carriers (NLCs) to improve its solubility, bioavailability, and therapeutic efficacy. The NLCs were prepared using an ultrasonic probe sonication technique using selected solid lipids (Gelucire 44/14), liquid lipids (Labrafil M 1944), and surfactants (Monoemul 80). A central composite design approach was adopted to optimize the NLCs. The optimized CLZ-loaded NLCs were evaluated in terms of particle size, zeta potential, surface morphology, crystallinity, drug loading, and in-vitro CLZ release studies. The optimized CLZ-loaded NLCs showed a particle size, zeta potential, and entrapment efficiency of 115.1 ± 2.48 nm, −17 mV and 96.74 ±1.82%, respectively. The morphology revealed the coarsely spherical shape of NLCs. Fourier transform infrared spectroscopy indicated the physical interaction between the CLZ and lipids rather than chemical interaction. The results of powder X-ray diffraction and differential scanning calorimetry showed the conversion of crystalline to amorphous form of CLZ and distributed molecular level in lipid matrix. In the in-vitro release study, pure CLZ showed 14±1.86% release, whereas CLZ-loaded NLC showed initial burst release (20.0±0.56%) followed by sustained release (69.0±1.03%) up to 24 hours. Collectively, results revealed that the developed novel CLZ-loaded NLCs could be a potential formulation to improve efficacy by increasing solubility and prolonging CLZ release and bioavailability with enhanced patient compliance and reduced side effects.

Synthesis of In2Se3 nanoparticles with variable molar ratio and its investigation of structural, optical, and photocatalytic activity for the degradation of hazardous organic dyes

In this article, In2Se3 nanoparticles (NPs) with varying Se/In molar ratios (ranging from 1.3 to 2.1 in increments of 0.2) were synthesized using a simple co-precipitation method. The morphology, crystallization, and chemical stoichiometry of the resulting NPs were analyzed using transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) patterns, and energy-dispersive X-ray (EDX) analysis. The structure and chemical bonding of the samples were determined through Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, confirming the XRD results. Additionally, the optical properties were assessed using UV–Vis spectroscopy, revealing a band gap of approximately 1.6 eV for the In2Se3 NPs, which remained consistent across different Se/In molar ratios. The degradation of methylene blue (MB) and malachite green (MG) demonstrated that the samples with Se/In ratios of 1.3 and 1.9 were efficient photocatalytic materials for removing organic contaminants under visible light. The Brunauer-Emmett-Teller (BET) analysis highlighted improved textural parameters for the samples with Se/In ratios of 1.3 and 1.9 compared to the others. Mott-Schottky results indicated that the In2Se3 NPs behaved as n-type semiconductors. Electrochemical impedance spectroscopy (EIS) showed that the sample with a Se/In ratio of 1.9 exhibited lower charge-transfer resistance, which is a key factor in enhancing photocatalytic performance.

Synthesis and characterization of zeolite Y from agricultural and municipal wastes: A waste management approach

Here in, we reported the utilization of guinea corn husk (an agricultural waste) and aluminium can (a municipal waste) for low-cost and sustainable means of zeolite Y preparation. Sodium silicate and sodium aluminate precursors were prepared from guinea corn husk and aluminium wastes respectively. The obtained solutions of the precursors were directly and hydrothermally converted to zeolite Y at 100 °C crystallization temperature for 24 h. The resulting zeolitic material was characterized by its properties. In comparison with collected standard data and commercially available zeolite Y, zeolite Y was successfully prepared from the waste resources. The result of X-ray Diffraction (XRD) indicated zeolite Y with good crystallinity, especially at the characteristic 2θ of 6.23°, 10.9° and 11.86°. The elemental compositions observed from Energy Dispersive X-ray (EDX) are in appropriate proportion and also confirmed the product. The Fourier Transform Infrared (FTIR) spectra showed the major characteristic absorption bands of zeolite in the mid-infrared region. It can be concluded that re-using agricultural and municipal wastes for the preparation of zeolite Y was achieved. This is a sustainable means of preparation of zeolite Y through a waste management approach for potential applications in adsorption, catalysis and ion exchange.

Formulation and optimization of electrospun nanofiber films for ultrafast delivery of domperidone: In vitro and in-vivo characterization

Nanotechnology has significantly transformed drug delivery approaches by providing precise control of drug release kinetics and enhancing therapeutic effectiveness. Electrospun nanofiber films have unique features, including a significant surface-to-volume ratio and substantial porosity, resulting in enhanced patient adherence. The study was aimed at developing electrospun nanofiber films of domperidone for ultrafast release using polyvinyl alcohol (PVA). The nanofibers were prepared by electrospinning method and optimized using 32 factorial design. Electrospinning process parameters like feed rate, applied electric voltage, and tip-to-collector distance were optimized. The prepared nanofiber film was characterized using scanning electron microscopy, differential scanning calorimetry (DSC), Fourier transform infrared microscopy (FTIR), X ray diffraction (XRD), in-vitro diffusion, and permeation studies. The resultant domperidone-loaded nanofibers (diameters 280–565 nm) exhibited a uniform and highly porous structure. With an increase in applied voltage from 11 to 13 kV, entrapment efficiency increased, and fiber diameter decreased. DSC and XRD results confirmed the amorphous nature of the domperidone. The FTIR study confirmed the compatibility between domperidone and PVA. The wetting and disintegration times of nanofibers were 8 and 4 s, respectively. Due to their nanosize, small particles with an increased surface area resulted in improved drug delivery through nanofibers (93.36% release within 10 min). The nanofiber film had a higher Cmax (398.8 ng/mL) and AUC (2078.593 ± 17.71 ng/mL.h) than the commercial tablet formulation (186.6 ng/mL and 1875.619 ± 10.38). Thus, domperidone nanofibers would be a promising approach for enhancing therapeutic and biopharmaceutical properties by providing ultra-fast delivery.

Enhancing osteoblast proliferation and bone regeneration by poly (amino acid)/selenium-doped hydroxyapatite

Among various biomaterials employed for bone repair, composites with good biocompatibility and osteogenic ability had received increasing attention from biomedical applications. In this study, we doped selenium (Se) into hydroxyapatite (Se-HA) by the precipitation method, and prepared different amounts of Se-HA-loaded poly (amino acid)/Se-HA (PAA/Se-HA) composites (0, 10 wt%, 20 wt%, 30 wt%) by in-situ melting polycondensation. The physical and chemical properties of PAA/Se-HA composites were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and their mechanical properties. XRD and FT-IR results showed that PAA/Se-HA composites contained characteristic peaks of PAA and Se-HA with amide linkage and HA structures. DSC and TGA results specified the PAA/Se-HA30 composite crystallization, melting, and maximum weight loss temperatures at 203.33 °C, 162.54 °C, and 468.92 °C, respectively, which implied good thermal stability. SEM results showed that Se-HA was uniformly dispersed in PAA. The mechanical properties of PAA/Se-HA30 composites included bending, compressive, and yield strengths at 83.07 ± 0.57, 106.56 ± 0.46, and 99.17 ± 1.11 MPa, respectively. The cellular responses of PAA/Se-HA composites in vitro were studied using bone marrow mesenchymal stem cells (BMSCs) by cell counting kit-8 assay, and results showed that PAA/Se-HA30 composites significantly promoted the proliferation of BMSCs at the concentration of 2 mg ml−1. The alkaline phosphatase activity (ALP) and alizarin red staining results showed that the introduction of Se-HA into PAA enhanced ALP activity and formation of calcium nodule. Western blotting and Real-time polymerase chain reaction results showed that the introduction of Se-HA into PAA could promoted the expression of osteogenic-related proteins and mRNA (integrin-binding sialoprotein, osteopontin, runt-related transcription factor 2 and Osterix) in BMSCs. A muscle defect at the back and a bone defect at the femoral condyle of New Zealand white rabbits were introduced for evaluating the enhancement of bone regeneration of PAA and PAA/Se-HA30 composites. The implantation of muscle tissue revealed good biocompatibility of PAA and PAA/Se-HA30 composites. The implantation of bone defect showed that PAA/Se-HA30 composites enhanced bone formation at the defect site (8 weeks), exhibiting good bone conductivity. Therefore, the PAA-based composite was a promising candidate material for bone tissue regeneration.

Antioxidant and dye degradation activity of green synthesized silver-iron oxide (Ag-Fe2O3) bimetallic nanoparticles

This research introduces an eco-friendly method for synthesizing silver-iron oxide bimetallic nanoparticles using cabbage peel extract, serving as both reducing and stabilizing agents. The successful production of nanoparticles is comprehensively analyzed through UV-Vis spectroscopy, Fourier transformation infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The UV, XRD and EDS results indicated the elemental composition of Ag and Fe, suggesting the formation of a silver-core iron-shell bimetallic nanoparticles with a size of 22.3 nm, which was followed by an assessment of their antioxidant and catalytic properties. The findings revealed notable antioxidant capabilities, along with the efficient degradation of methyl red and phenol red dye. Remarkably, the Ag-Fe2O3 bimetallic nanoparticles exhibited good scavenging activity, reaching 63.87% at a concentration of 1000 µg/mL. The most significant dye degradation is observed for phenol red, achieving a remarkable 78% degradation within just 8 minutes. These results indicate the potential of Ag-Fe2O3 bimetallic nanoparticles derived from cabbage peels as promising agents for antioxidant and catalytic applications, especially in addressing dye-contaminated wastewater concerns.

Electric-Field-Assisted Synthesis of Cu/MoS2 Nanostructures for Efficient Hydrogen Evolution Reaction.

Molybdenum sulfide-oxide (MoS2, MS) emerges as the prime electrocatalyst candidate demonstrating hydrogen evolution reaction (HER) activity comparable to platinum (Pt). This study presents a facile electrochemical approach for fabricating a hybrid copper (Cu)/MoS2 (CMS) nanostructure thin-film electrocatalyst directly onto nickel foam (NF) without a binder or template. The synthesized CMS nanostructures were characterized utilizing energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and electrochemical methods. The XRD result revealed that the Cu metal coating on MS results in the creation of an extremely crystalline CMS nanostructure with a well-defined interface. The hybrid nanostructures demonstrated higher hydrogen production, attributed to the synergistic interplay of morphology and electron distribution at the interface. The nanostructures displayed a significantly low overpotential of -149 mV at 10 mA cm-2 and a Tafel slope of 117 mV dec-1, indicating enhanced catalytic activity compared to pristine MoS2.This research underscores the significant enhancement of the HER performance and conductivity achieved by CMS, showcasing its potential applications in renewable energy.

Linearization and characterization of the Wemple – DiDomenico model of ZnO/Ni/ZnO tri-layer thin films prepared by ALD and DC magnetron sputtering

Our present work is devoted to analyzing the influence of Ni on the optical properties of ZnO thin films deposited on glass and Si (100) substrates, with the use of ALD for ZnO deposition and DC magnetron sputtering for Ni interlayer deposition. The compositions as well as the crystalline structure of various multilayer thicknesses of Ni (10, 30, 50, and 70 nm), that sandwiched between ZnO Films (70 nm), before being optically characterized, were carried out by the X-ray diffraction (XRD). Based on the XRD results, the crystallite size was increased with the increase of the Ni interlayer concentration. Additionally, the material densities for both ZnO and Ni show the expected close-to-bulk values in all formations, where the large cavities between atoms, on the films make the dislocation density become smaller and the surface roughness values decrease as well, with the increase of Ni interlayer concentration. Different optical properties were observed for different Ni content. The optical absorption coefficient (α), refractive index (n), and extinction coefficient (k) have been deduced from the transmission T(λ) and absorption measurements A(λ). The optical energy gap Egoptare estimated from Tauc΄s extrapolation procedure and the Kubelka-Munk approach. The static refractive index (no), the oscillator energy (Eo), and the dispersion energy (Ed) are calculated using the Wemple-DiDomenico (WDD) theoretical model. Analysis of third-order nonlinear optical properties in crystalline ZnO/Ni/ZnO are being detailed. These promising results imply that the high-quality films produced by ALD, show how the insertion of Ni could enhance the quality of the optical properties of ZnO films.

Shale permeability and microstructural alternation during CO2 pre-fracturing: A mechanistic study

CO2 pre-fracturing technology represents a novel approach to CO2 fracturing, effectively enhancing carbon capture efficiency in shale reservoirs while increasing the recovery of hydrocarbon resources. This study systematically quantifies the impact of water injection on the pore structure and permeability of shale samples saturated with pre-injected CO2. Based on X-ray diffraction (XRD) and low-temperature nitrogen adsorption (LT-NA) results, the dominant mechanism of the swelling-chemical coupling effect in shale property is clarified. Pre-injected CO2 can effectively mitigate the impact of water absorption. After a reaction time of 7 days, the permeability of the CO2-involved hydrated shale samples is four times that of samples without CO2. Nevertheless, the influence of subsequently injected water on shale permeability persists, resulting in an 80% reduction in shale permeability. XRD and LT-NA results indicate that the swelling-chemical coupling effect is the dominant factor in shale property variation during CO2 pre-fracturing. In the initial stage, the decline in calcite and clay mineral content is significant, and chemical dissolution dominates the change in pore structure. As the reaction progresses, the intensity of chemical reactions weakens, and clay mineral swelling becomes the primary factor affecting the shale properties. In this stage, K+ generated from original minerals effectively inhibits clay mineral swelling. Therefore, the swelling-chemical coupling effects should be comprehensively considered during the CO2 pre-fracturing process, and an appropriate soaking time should be selected to maximize CO2 storage efficiency and oil and gas production.

Preparation of Eu2+ and Dy3+ co-doped Sr2MgSi2O7 translucent long afterglow glass-ceramics by recrystallization-melting and their luminescence properties

In this work, a novel recrystallization-melting method was used to prepare Eu2+ and Dy3+ co-doped Sr2MgSi2O7 translucency long afterglow glass-ceramics with complete crystal development. The synthesis mechanism is discussed by analyzing the detection results of X-ray diffraction, scanning electron microscopy, phosphorescence spectra, and afterglow attenuation curves. The effect of different firing temperatures and crystallization time on the crystalline phase content, crystal size, and luminescence properties of the Sr2MgSi2O7:Eu2+, Dy3+ glass-ceramics samples were examined. The results show that, as compared with the traditional melt crystallization method or the two-step method, the recrystallization–melting method is able to form some Sr2MgSi2O7:Eu2+, Dy3+ crystals first under a temperature that is lower than that of the glass transition. With increasing firing temperature and crystallization time, crystal growth and recrystallization reached an equilibrium state, accompanied by the generation of liquid glassy phases. It is found that the afterglow properties are proportional to the crystalline phase content and crystal size, with the latter having a more significant effect. Under the condition of firing at 1050 °C for 10 h, tetragonal Sr2MgSi2O7 crystals with a maximum size of 20 μm were successfully synthesized for the first time. These crystals exhibited high integrity and optimal afterglow performance, with a duration close to 2 h. The recrystallization-melting method suits industrial production on large scales, and the firing temperature is evidently lowered, which effectively reduces the energy consumption of the synthesis process and significantly improves the long afterglow performance.