Energy Dispersive X-ray Diffractometer Research Articles

Oxidative stress-induced cytotoxicity of HCC2998 colon carcinoma cells by ZnO nanoparticles synthesized from Calophyllum teysmannii

The field of green synthesis, namely using plant extracts for the production of metal nanoparticles, is rapidly gaining traction. Therefore, this study investigated the process of producing zinc oxide nanoparticles (ZnO NPs) using a water-based extract derived from the stem bark of Calophyllum teysmannii. Notably, this is the first documented utilization of this particular plant source. The presence of a distinct Ultraviolet-Visible (UV-Vis) absorption peak at 372 nm provided evidence for the creation of ZnO nanoparticles. The X-ray Diffractometer (XRD) and Field Emission Scanning Electron Microscopy (FESEM) investigations indicated that the nanoparticles exhibited sizes ranging from 31.5 to 59.9 nm and had spherical morphologies. Energy Dispersive X-ray Diffractometer (EDX) analysis verified the elemental composition of the ZnO nanoparticles, whereas the Fourier Transform Infrared (FTIR) spectra showed clear peaks, demonstrating their production. The FTIR examination of the C. teysmannii extract revealed peaks at around 3370 cm− 1, indicating the presence of phenolic compounds. These chemicals are likely responsible for the reduction and stabilization of the ZnO NPs. The high-resolution X-ray Photoelectron Spectroscopy (XPS) spectra clearly revealed separate peaks corresponding to Zn 2p and O 1s, providing confirmation of the chemical states and bonding contexts. The Raman Spectroscopy analysis revealed a distinct peak at around 425 cm⁻¹, confirming the presence of the wurtzite structure. The harmful effects of ZnO nanoparticles on HCC2998 (a kind of human colon cancer) and Vero (a type of monkey kidney epithelial) cells were evaluated using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT), dichlorodihydrofluorescein diacetate (DCFH-DA), and boron-Dipyrromethene (BODIPY) assays. The cancer cells underwent cell death due to oxidative stress in a dose-dependent manner, as confirmed by microscopic and flow cytometry investigations.

Cobalt concentration effect on the Structural, Magnetic and Optical properties of Zn1-xCoxSe Nanoparticles

Cobalt doped Zinc selenide (Zn1-xCoxSe where x = 0.00,0.03, 0.05, 0.07, 0.09, 0.1, 0.15) nanoparticles are synthesized using co-precipitation method. For studying structural properties of prepared samples, nanoparticles are characterized by XRD (X-ray diffraction),SEM (Scanning Electron Microscope) with EDX (Energy Dispersive X-ray Diffractometer), HRTEM (High resolution transmission electron microscope),Elemental composition confirmed by EDX (Energy Dispersive X-ray Diffractometer), Inductively coupled plasma (ICP) spectroscopy test and XPS (X-ray photoelectron microscope). XRD study confirms that prepared samples are crystalline in nature and size is appeared in nanometer range with cubic structure. Optical investigation is done by UV–visible spectra and PL spectra at room temperature which indicates change in energy band gap as doping of cobalt increases in host material due to quantum confinement which shows the altered optical properties due to doping of transition metal in host material. FTIR (Fourier transform infra-red) spectroscopy reports presence of different functional groups in nanoparticles and thermal stability is confirmed by TG/DTA(Thermogravimetric) analysis. Magnetic analysis by using ESR (electron spin resonance) and VSM (Vibrating Sample Magnetometer) confirms presence of ferromagnetic coupling in cobalt doped zinc selenide nanoparticles which make these nanoparticles suitable for using in different devices e.g. in magnetic storage devices, magnetic imaging, magneto-optics and sensors etc. Combined semiconducting and magnetic nature of these Co doped ZnSe nanoparticles make them useful in spintronics, magnetic storage devices etc applications.

Zno Loaded Singgora Roof Tiles as Heterogeneous Catalyst for Waste Cooking Oil Biodiesel

This study aimed to utilize the waste cooking oil (WCO) into biodiesel using a novel waste Singgora roof tiles wet impregnated with zinc oxide (ZnO) as a heterogeneous catalyst. The motivation behind this choice stems from the non-recyclable nature of Singgora roof tiles and their potential applicability in biodiesel synthesis. The catalyst was characterized by X-ray Fluorescence (XRF) and scanning electron microscopy (SEM) with energy-dispersive X-ray diffractometer (EDX). A two-step transesterification method was employed to reduce the concentration of free fatty acids (FFA) in the WCO. The process started by treating the WCO with sulfuric acid (H2SO4) to diminish the levels of free fatty acid (FFA), followed by the utilization of the Singgora roof tiles catalyst in the subsequent step. A maximum yield of 96.96% biodiesel was obtained under the optimal conditions, which included a methanol-to- oil ratio of 12:1, a catalyst concentration of 1 wt.%, a reaction temperature of 65 °C, and a 2-hour reaction time. The quality of the biodiesel produced was analyzed according to biodiesel standards specified in the ASTM D6751, EN 14214, and AOCS, and were within the ranges. The study demonstrates the potential of using Singgora roof tiles as a heterogeneous catalyst in biodiesel production, offering a promising approach to repurposing non-recyclable materials and advancing sustainable biodiesel production methods.

Nano structural and opto-magnetic investigation of Co–Ni co-doped ZnSe for spintronics

Cobalt and Nickel co-doped ZnSe nanoparticles with fixed concentration of nickel and varying concentration of cobalt formulated as Zn0.95-xCoxNi0.05Se(where x = 0.0, 0.01, 0.03, 0.05) are synthesized by using wet-chemical route by co-precipitation method at 60 °C and calcined at 200 °C temperature. The structural study is carried out by applying X-ray diffractometer (XRD) characterization technique and found the synthesized material having crystallite size in nanometer range 08–37 nm with cubic zinc blende structure. Size increment of nanoparticles has been obtained as the concentration of cobalt was increased. Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Diffractometer (EDX) and Transmission-Electron Microscopy (TEM) analysis of the nanoparticles are performed to study morphology and confirming presence of doped elements by forming Cobalt and Nickel co-doped ZnSe nanoparticles. Fourier-Transform Infrared (FTIR) study is carried out to detect presence of different functional groups, bending and stretching in molecules. Energy band gap is also calculated using UV–Visible spectroscopy and found increment in band gap due to quantum confinement effect. Ferromagnetism is recorded in these Co and Ni co-doped ZnSe nanoparticles using Vibrating-Sample Magnetometer (VSM) characterization technique at 300 K and 15 K.This inducted magnetism is due to the presence of exchange interactions between electrons of different elements. Electron spin resonance (ESR) spectra is also recorded at room temperature by the presence of paramagnetic defects in the samples.

KNO3-Loaded Coffee Husk Ash as a Heterogeneous Alkali Catalyst for Waste Frying Oil Valorization into Biodiesel.

In this study, a heterogeneous basic catalyst was synthesized from a catalyst composite material (CCM) of coffee husk ash and char mixture (A/C) impregnated with KNO3 and employed to transesterify crude waste frying oil (WFO). The effect of CCM calcination temperature (CCMCT) (500-700 °C) on the catalyst physicochemical properties was investigated. A differential scanning calorimeter was used to examine potential phase changes during the calcination of A/C and CCM. The catalysts from each CCMCT were characterized by X-ray diffraction (XRD), Brunauer-Emmet-Teller surface area analyzer, scanning electron microscopy (SEM), SEM with energy-dispersive X-ray diffractometer, colorimeter, and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrometer. The methoxy functional group FTIR peak integral value and the dynamic viscosity of the biodiesel synthesized by each catalyst were used to determine the qualitative WFO conversion. Furthermore, the quantitative WFO conversion was determined using nuclear magnetic resonance (1H NMR) analysis. Crystallinity, elemental composition, basicity, and morphology of catalysts were highly dependent on the CCMCT. Without transesterification condition optimization (reaction temperature of 45 ± 2.5 °C, catalyst loading of 3 wt %, methanol to oil molar ratio of 12:1, and reaction time of 1 h), a higher catalytic performance (72.04% WFO conversion) was reached using a catalyst from the CCMCT of 600 °C. When using a coffee husk ash catalyst without KNO3 impregnation (C-00-600), the WFO conversion was only 52.92%. When comparing the C-25-600 and C-00-600 catalysts, it was observed that KNO3 impregnation had a substantial impact on the catalyst crystallinity, basicity, and morphology.

Effect of calcium doping on structural, magnetic and magneto-caloric properties of La0.55CaxSr0.45-xMnO3 manganites

Effect of calcium (Ca) doping on structural, magnetic and magnetocaloric properties of calcium-strontium doped lanthanum manganite La0.55CaxSr0.45-xMnO3 (x = 0.00, 0.05, 0.1, 0.25) prepared by solid state reaction technique has been reported in this paper. Room temperature XRD measurements reveal rhombohedral structure for all the samples. Microstructural analysis have been done by the field emission scanning electron microscopy and elemental compositions are determined by energy dispersive X-ray diffractometer. It is observed that the lattice parameters as well as Mn-O-Mn bond angle are decreased with increasing Ca content which has changed the magnetic and magnetocaloric properties and tuned Curie temperature (TC) toward the room temperature. Magnetization measurement as a function of temperature reveals a reduction of magnetic saturation and decrease in Curie temperature from 354 K to 311 K with increase in Ca content from 0.00 to 0.25, respectively. A second order ferromagnetic to paramagnetic phase transition is noticed from their Arrots plots. The magnetocaloric effect is calculated in terms of entropy change and relative cooling power from the isothermal magnetization measurements around TC using Maxwell’s thermodynamic relations. The maximum entropy change and relative cooling power are observed to be decreased while TC shifted toward the room temperature with increase in Ca content in our studied polycrystalline manganite.

Magnetocaloric properties and analysis of the critical point exponents of Pr0.55CaxSr0.45-xMnO3 (x = 0.00, 0.05, 0.1 and 0.2) at PM-FM phase transition

The polycrystalline manganite Pr0.55CaxSr0.45-xMnO3 (x = 0.00, 0.05, 0.1, and 0.2) has been prepared by the solid state reaction technique to investigate its crystal structure, magnetic, and magnetocaloric properties. Critical behaviour around PM-FM phase transition has also been analyzed through various methods including modified Arrott plots (MAP), and critical isotherm analysis of Pr0.55CaxSr0.45-xMnO3 (x = 0.00, 0.05, 0.1, and 0.2). XRD analysis reveals that all the samples are found to be crystallized in the orthorhombic system with Pnma space group and lattice parameters a, b and c as well as the cell volume are found to decrease with increasing Ca (x) content. Microstructure is observed with the field emission scanning electron microscopy (FESEM) photograph and elemental compositions are determined by energy dispersive X-ray diffractometer (EDX). Temperature and field dependent magnetization measurement disclose that all the samples undergo second-order FM to PM phase transition but the Curie temperature (TC) value decreases from 290 K to 245 K with the increase in Ca (x) content from 0.00 to 0.20. The magnetocaloric effect (MCE) in terms of maximum entropy change, (-ΔSm)max and relative cooling power (RCP) was calculated from isothermal magnetization measurements around TC, using Maxwell’s thermodynamic relations. Both (−ΔSm)max and RCP increases with increasing Ca content suggests the suitability of this compound as a potential solid state refrigerent. Contribution of itinerant electron in the entropy change is found from modulating MCE with Landau theory of phase transition.

Magnetic properties of La0.55CaxSr0.45−xMnO3 perovskite manganite

Conventional solid-state reaction technique was used to prepare the studied samples La0.55CaxSr0.45−xMnO3 (x = 0.0, 0.1, 0.2). Their structural and magnetic properties have been investigated to find the effect of calcium doping on the D.C. and A.C. magnetic properties of the compounds. Room temperature XRD investigations confirm rhombohedral structure with space group R-3c for all the samples. Lattice parameter is found to decrease with increase in Ca(x) content. Microstructure was examined from the images taken by Scanning Electron Microscopy (SEM) and chemical compositions were determined by an energy dispersive X-ray diffractometer (EDX). The zero-field cooled (ZFC) and field cooled (FC) DC magnetization measurements reveal paramagnetic (PM) to ferromagnetic (FM) transition in them upon cooling through their Curie temperature (TC). But the FM state coexists with the residual canted anti-ferromagnetic state rather than a pure FM state in the samples. The TC values are dependent on Ca(x) content of the samples. Moreover, XRD analysis and EDX data reveals the presence of Mn deficiency in the studied samples. Presence of minor secondary Mn3O4 phase creates this deficiency resulting a significant decrease in TC and strongly influences the magnetic properties. The values of A.C. permeability (μʹ) also depend on Ca(x) content as well as grain size that can be explained by Globus equation. However, μʹ values of the samples remain almost constant over a wide range of frequency which indicates the compositional stability of the perovskites. The magnetic modulus demonstrates the dynamics of their A.C. permeability by screening out the stray/any other effects in them. The Nyquist plots of magnetic modulus of the samples show the type of their magnetic relaxation.

Structural, dielectric and magnetic properties of La0.55Sr0.45MnO3 polycrystalline perovskite

Polycrystalline perovskite La0.55Sr0.45MnO3 has been prepared by the conventional solid-state reaction route using planetary ball milling technique. The structural properties have been investigated using XRD and SEM data. Rhombohedral structure with space group R-3c of the sample is confirmed by room temperature XRD investigation. Microstructure and chemical composition were determined by Scanning Electron Microscopy (SEM), which includes an energy dispersive X-ray diffractometer (EDX).The study of the dielectric properties of the sample reveals that La0.55Sr0.45MnO3 possesses a high dielectric constant at room temperature and at low frequencies. The real part of the dielectric constant ε’ is also observed to be strongly dependent on the temperature and the best properties are found in the sample at room temperature for which ε’ ≈104 up to f = 4x106 Hz. The dispersion of dielectric constants at low frequency is explained in the light of Maxwell–Wagner model. A pronounced increase in Capacitance C is observed from 273 K to 298 K and likely to be caused by the redistribution of ions due to the thermal agitation. The resistivity decreases with increasing temperature indicating that the sample has a semiconductor-like behavior. The constant value of μ’ over a wide range of frequency indicates the compositional stability and the range of the suitability of the perovskite. A significant decrease of ac permeability has occurred around 298 K indicating a magnetic phase transition from ferromagnetic to paramagnetic state. Low temperature magnetization measurement reveals paramagnetic to ferromagnetic (FM) transition upon cooling at TC = 244 K. But the FM state coexists with the residual canted AFM (anti-ferromagnetic) state rather than a pure FM state. Presence of external field H favors the FM phase which expands at the expense of the AFM phase. Thus M−H measurement reveals high saturation magnetization.

Effect of different sintering conditions on microstructural characterisation of Co-Cr metal laser powder

Co-Cr alloys have been used for many years in dentistry. In recent years, the fabrication of prosthetic restorations from Co-Cr alloys by metal laser sintering method has become widespread. This method is a combination of powder metallurgy and three-dimensional printing technologies. The surface microstructure of the material and the different phases formed on the surface of the material after sintering and heat treatment are extremely important since these metal substructures are layered with dental porcelain in fixed prosthetic dentistry. In this study, characterisation of Co-Cr alloy samples produced by direct metal laser sintering (DMLS) method and sintering under various atmospheric conditions were performed with X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray diffractometer (EDX). It was observed that sintering with different methods under various atmospheric conditions affected the XRD phase intensities. The sintering in the argon gas atmosphere yielded a more significant phase separation that facilitates the identification of different phases in XRD patterns.

Magnetic, magnetocaloric, and dielectric properties of polycrystalline perovskite La0.7Ca0.2Pb0.1CoO3

The polycrystalline perovskite La0.7Ca0.2Pb0.1CoO3 has been prepared by the conventional solid-state reaction technique, and then the structural, magnetic, magnetocaloric, and dielectric properties of the sample have been investigated. The monoclinic structure with space group I2/a of the sample is confirmed by X-ray diffraction investigation at room temperature. The microstructure was examined by scanning electron microscopy (SEM), and chemical composition was determined using an energy dispersive X-ray diffractometer attached to the SEM. Magnetic measurement reveals that the sample undergoes ferromagnetic to paramagnetic transition with increasing temperature and behaves as a soft magnetic material. Field cooled and zero-field cooled dc magnetization curves at low field and low temperature show divergence, indicating the coexistence of antiferromagnetic and ferro-magnetic clusters in the sample. Magnetic inhomogeneity of the sample has also been clearly confirmed by the divergence between the Curie temperature, Tc, and the paramagnetic Curie temperature, θ. The sample also shows a magnetocaloric effect at a very low field (H = 0.01 T). The high negative value of the real part of complex permittivity, ε′, reveals metallic behavior of the sample at low frequency around room temperature. However, the frequency dependent ac conductivity (σ) exhibits three distinct bands, namely, the metallic, insulating, and anomalous band, around room temperature. Temperature dependent ε′ reveals that the sample undergoes insulator to metallic transition above −20 °C.

Preparation of carbon nanotube/copper/carbon fiber hierarchical composites by electrophoretic deposition for enhanced thermal conductivity and interfacial properties

A facile electrophoretic deposition method was proposed to deposit copper (Cu) and carbon nanotubes (CNTs) on the surface of carbon fiber (CF) to improve the thermal conductivity and interfacial properties of carbon fiber-reinforced polymer (CFRP) composites. Surface morphologies, crystallographic properties, thermal conductivity, interlaminar shear strength (ILSS) and element distribution of the composites were characterized by scanning electron microscopy (SEM), X-ray diffraction, thermal constant analysis, short-beam bending tests and SEM energy-dispersive X-ray diffractometer (SEM–EDX), respectively. The results indicate that the presence of Cu and CNTs generated networks and bridges with each other, which produced continuous heat conduction pathways and significantly enhanced both the specific surface area and roughness of the fiber surface. These pathways obviously promoted an improvement in the thermal and interfacial properties. The thermal conductivity and ILSS of the CNTs–Cu–CF/epoxy composites increased by 292 and 39.5%, respectively, compared with CF/epoxy composites. Therefore, this method is anticipated to be utilized in the future fabrication of multifunctional CFRP composites.

Bulk Crystal Growth, and High-Resolution X-ray Diffraction Results of LiZnAs Semiconductor Material

LiZnAs is being explored as a candidate for solid-state neutron detectors. The compact form, solid-state device would have greater efficiency than present day gas-filled 3He and 10BF3 detectors. Devices fabricated from LiZnAs having either natural Li (nominally 7.5% 6Li) or enriched 6Li (usually 95% 6Li) as constituent atoms may provide a material for compact high efficiency neutron detectors. The 6Li(n,t)4He reaction yields a total Q-value of 4.78 MeV, an energy larger than that of the 10B reaction, which can easily be identified above background radiations. LiZnAs material was synthesized by preparing equimolar portions of Li, Zn, and As sealed under vacuum (10−6 Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace (Montag et al. in J Cryst Growth 412:103, 2015). The raw synthesized LiZnAs was purified by a static vacuum sublimation in quartz (Montag et al. in J Cryst Growth 438:99, 2016). Bulk crystalline LiZnAs ingots were grown from the purified material with a high-temperature Bridgman-style growth process described here. One of the largest LiZnAs ingots harvested was 9.6 mm in diameter and 4.2 mm in length. Samples were harvested from the ingot and were characterized for crystallinity using a Bruker AXS Inc. D8 AXS Inc. D2 CRYSO, energy dispersive x-ray diffractometer, and a Bruker AXS Inc. D8 DISCOVER, high-resolution x-ray diffractometer equipped with molybdenum radiation, Gobel mirror, four bounce germanium monochromator and a scintillation detector. The primary beam divergence was determined to be 0.004°, using a single crystal Si standard. The x-ray based characterization revealed that the samples nucleated in the (110) direction and a high-resolution open detector rocking curve recorded on the (220) LiZnAs yielded a full width at half maximum (FWHM) of 0.235°. Sectional pole figures using off-axis reflections of the (211) LiZnAs confirmed in-plane ordering, and also indicated the presence of multiple domains. The LiZnAs bulk crystals exhibited a Primitive Cubic Bravais lattice instead of the commonly reported Face-centered Cubic Bravais lattice. The lattice constant was determined to be 5.5146 ± 0.0003 A.

TH-AB-209-11: Breast Microcalcification Classification Using Spectral X-Ray Coherent Scatter Computed Tomography

Purpose: To investigate the ability of Coherent Scatter Computed Tomography (CSCT) to distinguish non-invasively between type I calcifications, consisting of calcium oxalate dihydrate (CO) compounds which are more often associated with benign lesions, and type II calcifications containing hydroxyapatite (HA) which are predominantly associated with malignant tumors. Methods: The coherent scatter cross sections of HA and CO were measured using an energy dispersive x-ray diffractometer. The measured cross sections were introduced into MC-GPU Monte Carlo simulation code for studying the applicability of CSCT to discriminate between the two types of microcalcifications within the whole breast. Simulations were performed on a virtual phantom with inserted HA and CO spots of different sizes and placed in regions of interest having different background compositions. We considered a polychromatic x-ray source and an energy resolving photon counting detector. We applied an algorithm that estimates scatter components in projection space in order to obtain material-specific images of the breast. As material components adipose, glandular, HA and CO were used. The relative contrast of HA and CO components were used for type I and type II microcalcification discrimination. Results: The reconstructed CSCT images showed material-specific component-contrast values, with the highest CO or HA component contrast corresponding generally to the actual CO or HA feature, respectively. The discrimination performance varies with the x-ray intensity, calcification size, and background composition. The results were summarized using receiver operating characteristic (ROC) analysis with the area under the curve (AUC) taken as an overall indicator of discrimination performance and showing high AUC values up to unity. Conclusion: The simulation results obtained for a uniform breast imaging phantom indicate that CSCT has potential to be used as a non-invasive method for discrimination between type I and type II microcalcifications.

High Temperature Wear Behaviour of Nano/Micro B4C Reinforced Aluminium Matrix Composites Fabricated by an Ultrasonic Cavitation-Assisted Solidification Process

The micro- and nano-composites containing 2, 4 and 6 by wt% of B4C particles in aluminium are fabricated using stir and ultrasonic cavitation-assisted casting processes. The fabricated composites are characterized by using scanning electron microscopy, X-ray diffractometer. The dry sliding wear behaviour of the prepared composites are investigated by using pin on disc method at an applied load of 4, 8, 12, 16 N for pin temperatures of 100 and 200 °C. The wear study at room temperature is also carried out for comparison. The investigations indicate that the wear resistance of the nano particle-reinforced composites are better than those of the micro B4C particle-reinforced composites under all loads and different temperatures. Analysis of wear surface and debris by scanning electron microscopy with energy dispersive X-ray diffractometer reveals the nature of wear mode of samples. It is also observed that the predominant wear mechanism for pure aluminium at 100 and 200 °C are adhesion and metal flow respectively, whereas for fabricated composites abrasion, delamination and oxidation are the most dominant wear mechanisms.

Synthesis, characterization and low concentration ethanol sensing performance of sol–gel derived La(III) doped tin oxide

Nanocrystalline undoped and lanthanum(III) doped (2, 4 and 6 at%) tin oxide powders were synthesized using sol–gel processing from their water based precursor sols. Microstructures and surface morphologies of all powders were characterized using X-ray diffractometer, BET surface area, UV–Visible spectrophotometer, scanning and transmission electron microscope along with energy dispersive X-ray diffractometer. XRD and UV–Vis spectral analyses revealed decrease of tin oxide crystallite size on La(III) doping. 4 at% La(III) doped powder showed ~5 nm average particle size and ~42 m2/g surface area respectively. A systematic comparison study revealed that sensors made from 4 at% La(III) doped SnO2 powder exhibited optimum ethanol vapor sensing performance at operating temperature, 350 °C (response ~70 % for 10 ppm ethanol) with excellent response and recovery times. Even for very low concentration ethanol vapour (1 ppm) response observed was ~53 %. A possible mechanism for enhancing sensitivity on La(III) doping has been discussed.

Bulk crystal growth, and high-resolution x-ray diffraction results of LiZnP semiconductor material

Nowotny–Juza compounds continue to be explored as a candidate for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present day gas-filled 3He and 10BF3 detectors. The 6Li(n,t)4He reaction yields a total Q-value of 4.78MeV, larger than 10B, an energy easily identified above background radiations. Hence, devices fabricated from semiconducting compounds containing either natural Li (nominally 7.5% 6Li) or enriched 6Li (usually 95% 6Li) may provide a semiconductor material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and P sealed under vacuum (10−6Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace [1]. The synthesized material showed signs of high impurity levels from material and electrical property characterizations. A static vacuum sublimation in quartz was performed to help purify the synthesized material [2]. Bulk crystalline samples were grown from the purified material. An ingot 9.6mm in diameter and 4.0mm in length was harvested. Individual samples were characterized for crystallinity on a Bruker AXS Inc. D2 CRYSO, energy dispersive x-ray diffractometer, and a Bruker AXS D8 DISCOVER, high-resolution x-ray diffractometer with a 0.004° beam divergence. The (220) orientation was characterized as the main orientation with the D2 CRYSO, and confirmed with the D8 DISCOVER. An out-of-plane high-resolution rocking curve yielded a 0.417° full width at half maximum (FWHM) for the (220) LiZnP. In-plane ordering was confirmed by observation of the (311) orientation, where a rocking curve was collected with a FWHM of 0.294°.

Adsorption Characteristics of Sulfur-Functionalized Silica Microspheres with Respect to the Removal of Hg(II) from Aqueous Solutions

This paper presents the study of the adsorption characteristics of sulfur-functionalized silica microspheres (S-SMs), synthesized through co-condensation of tetraethyl orthosilicate with 3-mercaptopropyl trimethoxysilane (MPTMS) and bis(triethoxysilylpropyl) tetrasulfide (BTESPT) as sulfur ligands, with respect to the removal of Hg(II) from aqueous solutions. The synthesized adsorbents were characterized using a scanning electron microscope, an X-ray diffractometer, a nitrogen adsorption–desorption analyzer, a Fourier transform infrared spectrophotometer, and an energy dispersive X-ray diffractometer. The effects of pH, concentration, temperature, stirring time, and adsorbent reusability were studied via batch adsorption experiments. It was found that the optimal adsorption pH values for all synthesized adsorbents were between 5.8 and 8.2. The adsorption capacity of SMs was 20.0 mg/g and increased to 37.0 and 62.3 mg/g for BTESPT-SMs and MPTMS-SMs, respectively. Hg(II) adsorption was found to be exothermic in nature and followed the chemisorption mechanism. The Langmuir isotherm model was found to be the best fitted model for describing the isotherm data, while the kinetic data obeyed the pseudo-second-order kinetic model, in which film diffusion was found to be the rate-controlling step. The regeneration study using potassium iodide as a regeneration agent showed high reusability, up to five-cycle activity.

Synthesis and Characterization of Novel Sulfur-Functionalized Silica Gels as Mercury Adsorbents

This paper describes the synthesis, functionalization, and characterization of silica gels as mercury adsorbents. The synthesis was carried out according to the modified Stober method using tetraethyl orthosilicate [TEOS], 3-mercaptopropyl trimethoxysilane [MPTMS] and bis(triethoxysilylpropyl) tetrasulfide [BTEPST] as precursors. The functionalization was carried out via co-condensation and impregnation methods using MPTMS, BTESPT, elemental sulfur [ES], and carbon disulfide [CS2] as sulfur ligands. The choice of the sulfur ligands as precursors and functionalization agents was due to the existence of sulfur active groups in their molecular structures which were expected to have high affinity toward Hg(II) ions. The synthesized adsorbents were characterized by using scanning electron microscope, fourier transform infrared spectrophotometer, nitrogen adsorption/desorption, and energy dispersive X-ray diffractometer. The batch Hg(II) adsorption experiments were employed to evaluate the Hg(II) adsorption performances of the synthesized adsorbents under different pH values. The results revealed that the highest Hg(II) adsorption capacity was obtained for the SG-MPTMS(10) which was 47.83 mg/g at pH 8.5. In general, the existence of sulfur functional groups, especially MPTMS in the silica matrices, gave a significant enhancement of Hg(II) adsorption capacity and the sulfur functionalization via co-condensation method, which is potential as a superior approach in the mercury adsorbent synthesis.

Adsorption enhancement of elemental mercury onto sulphur-functionalized silica gel adsorbents

In this study, elemental mercury (EM) adsorbents were synthesized using tetraethyl orthosilicate (TEOS) and 3-mercaptopropyl trimethoxysilane as silica precursors. The synthesized silica gel (SG)-TEOS was further functionalized through impregnation with elemental sulphur and carbon disulphide (CS2). The SG adsorbents were then characterized by using scanning electron microscope, Fourier transform infra-red spectrophotometer, nitrogen adsorption/desorption, and energy-dispersive X-ray diffractometer. The EM adsorption of the SG adsorbents was determined using fabricated fixed-bed adsorber. The EM adsorption results showed that the sulphur-functionalized SG adsorbents had a greater Hg° breakthrough adsorption capacity, confirming that the presence of sulphur in silica matrices can improve Hg° adsorption performance due to their high affinity towards mercury. The highest Hg° adsorption capacity was observed for SG-TEOS(CS2) (82.62 μg/g), which was approximately 2.9 times higher than SG-TEOS (28.47 μg/g). The rate of Hg° adsorption was observed higher for sulphur-impregnated adsorbents, and decreased with the increase in the bed temperatures.