X-ray Powder Diffraction Patterns Research Articles

Crystal growth and characterization of L-Tryptophan doped zinc bis thiourea sulphate (TDZBTS) crystal using UV–Visible, FT-IR spectral studies, thermal studies, P-XRD & SEM-EDAX

The L-Tryptophan-doped Zinc Bis Thiourea Sulphate (TDZBTS) was successfully grown into crystals using slow evaporation method. The grown crystals were the subject of numerous investigations, including UV–Visible spectra, FTIR, thermal analysis (TG-DTA), SEM-EDAX spectra, and powder X-ray diffraction. Spectral analyses in the UV–Visible region were used to determine the optical and electronic properties of (TDZBTS). The calculated band gap energy is 4.78 eV. By using FTIR analysis, the functional group of TDZBTS crystals doped with L-Tryptophan was observed. The TDZBTS is thermally stable up to 240 °C, according to TG-DTA studies. The powder X-ray diffraction pattern confirms the crystallinity type and purity of the grown crystals. An analysis of grown crystals using a Scanning Electron Microscope reveals that they are of good quality and have a layer-like structure. The characterization studies have shown that synthesized crystals exhibit favorable properties for nonlinear optical applications.

Driekopite, Ideally PtBi, a New Mineral Species from the Driekop Platinum Pipe, Republic of South Africa

Abstract The new mineral driekopite, ideally PtBi, was found in a concentrate from the Driekop mine, one of three zoned Pt pipes (mined from 1925 to 1930) that crosscut the layered mafic and ultramafic sequences of the eastern Bushveld Complex, Republic of South Africa. The holotype grain of driekopite (∼ 22 × 13 μm) occurs in a complex, rounded aggregate ∼120 μm in diameter, in association with isoferroplatinum (Pt3Fe), hollingworthite (RhAsS), geversite (PtSb2), insizwaite (PtBi2), andrieslombaardite (RhSbS), stibiopalladinite (Pd5Sb2), sobolevskite (PdBi), possible tatyanaite (Pt9Cu3Sn4), osmium-bearing tulameenite (Pt2FeCu), and Pt-Fe alloy (∼Pt2Fe). Driekopite appears slightly orange under reflected light compared to Pt-Fe alloys. It shows moderate to strong bireflectance, varying from light yellow to brownish yellow, no pleochroism or internal reflections, and moderate to strong anisotropism. The empirical formula, calculated from the average of six wavelength-dispersive spectrometry analyses made on five grains, on the basis of two atoms, is (Pt0.68Pd0.31Fe0.01)Σ1.00(Bi0.53Sb0.43As0.02Sn0.02S0.01)Σ1.01. The mineral is hexagonal, space group P63/mmc (#194) with the refined unit-cell dimensions a = 4.1993(5), c = 5.6194(6) Å, V = 85.82 Å3, Z = 2, and Dcalc = 12.91 g/cm3. Driekopite is isostructural with NiAs, with mixed compositions of Pt and Pd at the 2a site (0.55:0.45, respectively) and Bi and Sb at the 2c site (0.63:0.37, respectively). Its crystal structure was refined to wR = 6.3% using 13 unique Laue reflections obtained using synchrotron radiation. The six strongest lines for the powder X-ray diffraction pattern calculated from the crystal structure refined from synchrotron data is [d in Å (I) (hkl)]: 3.0531 (92) (101), 2.2234 (100) (102), 2.0997 (77) , 1.5266 (28) (202), 1.2347 (24) , 1.1676 (18) . The holotype grain of driekopite is observed to be paragenetically later than isoferroplatinum and hollingworthite and is considered to be synformational with Bi-bearing geversite, insizwaite, andrieslombaardite, and sobolevskite. The entire aggregate containing these platinum-group minerals is overgrown by a rim of tulameenite and Pt-Fe alloy (∼Pt2Fe), indicating they are paragenetically the last minerals to form. Experiments designed to synthesize PtBi over the range of 200 to 500 °C were all successful. Synthetic PtBi melts congruently at 765 °C, suggesting that driekopite likely crystallized at sub-magmatic temperatures.

Enhancement of Photocatalytic Activity and Microstructural Growth of Cobalt-Substituted Ba1−xCoxTiO3 {x = 0, …, 1} Heterostructure

The photocatalytic degradation process and absorption kinetics of the aqueous solution of the Cibacron Brilliant Yellow 3G-P dye (Y) were investigated under UV-Vis light. Pure barium titanate BaTiO3 (BT) and cobalt ion-substituted barium Ba1−xCoxTiO3 (x = 0, …, 1) nano-compound powders (BCT) were synthesized using the sol–gel method and colloidal solution destabilization, and utilized as photocatalysts. The powder X-ray diffraction (PXRD) crystal structure analysis of the BT nanoparticles (NPs) revealed a prominent reflection corresponding to the perovskite structure. However, impurities and secondary phase distributions were qualitatively identified in the PXRD patterns for x ≥ 0.2 of cobalt substitution rate. Rietveld refinements of the PXRD data showed that the BCT nano-compound series undergoes a transition from perovskite structure to isomorphous ilmenite-type rhombohedral CoTiO3 (CT) ceramic. The nanoparticles produced displayed robust chemical interactions, according to a Fourier transform infrared spectroscopy (FTIR) analysis. The BT and BCT nanoparticles had secondary hexagonal phases that matched the PXRD results and small aggregated, more spherically shaped particles with sizes ranging from 30 to 114 nm, according to transmission electron microscopy (TEM). Following a thorough evaluation of BCT nano-compounds with (x = 0.6), energy-dispersive X-ray (EDX) compositional elemental analysis revealed random distributions of cobalt ions. Through optical analysis of the photoluminescence spectra (PL), the electronic structure, charge carriers, defects, and energy transfer mechanisms of the compounds were examined. Due to the cobalt ions being present in the BT lattice, the UV-visible absorption spectra of BCT showed a little red-shift in the absorption curves when compared to pure BT samples. The electrical and optical characteristics of materials, such as their photon absorption coefficient, can be gathered from their UV-visible spectra. The photocatalytic reaction is brought about by the electron–hole pairs produced by this absorption. The estimated band gap energies of the examined compounds, which are in the range of 3.79 to 2.89 eV, are intriguing and require more investigation into their potential as UV photocatalysts. These nano-ceramics might be able to handle issues with pollution and impurities, such as the breakdown of organic contaminants and the production of hydrogen from water.

Directional dependent magnetization in BaFe12O19 thin film

The thin film of BaFe12O19 (BHF) on a silicon substrate has been prepared by the pulse laser deposition method. The crystal structure, morphology, elemental analysis, and magnetic properties have been investigated by using X-Ray Diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy, elemental dispersive x-ray analysis, and vibrating sample magnetometry, respectively. The Rietveld refinement of XRD patterns of BHF powder has been performed to study the crystal structure and lattice parameters. Peak shifting in XRD pattern and Raman spectra for the thin film have been observed compared to that of powder sample. It could be due to the existence of stress at the interface of film and substrate. The magnetic hysteresis loops (M-H loops) of BHF thin film and powder were traced at 60 K and 300 K. The M-H loops of BHF suggest the hard and soft magnetic nature of powder and thin film, respectively. There is a large difference has been observed between saturation magnetization measured by applying a magnetic field parallel and perpendicular directions of the thin film. The bifurcation in zero field cooling (ZFC) and field cooling (FC) magnetization curves reveals the magnetic frustration in the thin films.

Fractal features of pH-sensitive bimodal mesoporous silica-supported bipyridine-proline organocatalysts with core-shell structure and their application in asymmetric aldol reaction

Using poly(acrylic acid) (abbreviated as PAA) as a shell, bimodal mesoporous silicas (abbreviated as BMMs) as a core, and bipyridine-proline (abbreviated as Z) as an active species, a facile approach for preparation of the P-Z@BMMs nanocomposites with core–shell structure was proposed, which was used as a suitable pH-sensitive catalyst for asymmetric aldol reaction between p-nitrobenzaldehyde and cyclohexanone. Their microstructural features and physicochemical properties were extensively characterized by various methods, such as powder X-ray diffraction patterns, N2 adsorption–desorption isotherms, the scanning (and transmission) electron microscopy images, the dynamic light scattering measurements, the thermogravimetric analysis, the elemental analysis, and the Fourier transform infrared spectroscopy spectra. Particularly, their fractal evolution, the pair distance distribution function, and the Porod plots were demonstrated via the small-angle X-ray scattering patterns. The results elucidated that the PAA was successfully incorporated onto the external amino-modified surfaces of the mesoporous BMMs, and the particles having PAA grafted thereon had a pH-responsive shell in thickness of around 0.97 nm for controlled release of Z species by adjusting pH value of the reaction medium. Besides, the synthesized P-Z@BMMs presented the satisfactory catalytic yields (around 80%) in comparison with the homo- and heterogeneous catalytic system using Z or Z@BMMs as the catalysts.

Chemical Synthesis, Characterization, and Computational Investigation of Two Schiff Bases Derived From 3-(2-Hydroxyphenyl)-4-amino-4H-1,2,4-triazole-5- thiol and Their Corresponding Oxovanadium(IV) Complexes

A triazole, 2-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)phenol, has been prepared from 2-hydroxybenzoic acid by routine multi-step chemical synthesis. It was then used in synthesizing two different Schiff base ligands (L1 and L2). Their respective oxovanadium (IV) complexes (ML1 and ML2) were consequently synthesized and characterized by different experimental techniques like elemental analysis, FTIR spectroscopy, UV-Visible spectroscopy, and EPR spectrometry. The cyclic voltammetry measurements showed the electrochemically stable nature of the complexes. The powder X-ray diffraction patterns revealed the presence of monoclinic crystals with particle sizes of ca. 15-17 nm for both complexes. DFT calculations were performed for the determination of geometrical models, energetic stability, electronic properties, spectral features, and reactivity of the synthesized ligands and complexes. The spectral characterization of the complexes suggests a square-pyramidal geometry around VO (IV)group and was supported by computational results derived from the proposed models. This work shows that computational calculation along with experimental characterization provides better insights into new chemical compounds and their properties that could be performed in parallel as a regular tool.

Impact of Mg-doping on the structural, optical, and magnetic properties of CuO nanoparticles and their antibiofilm activity

Doping in metal oxide systems is being chased by many researchers since it is enhancing their properties. In the present study, Cu1-xMgxO nanoparticles, capped with EDTA were synthesized by the chemical co-precipitation method, with x = 0.000, 0.005, 0.010, 0.015, and 0.020, and further characterized by different techniques. The impact of doping by Mg2+ ions on the structural, optical, and magnetic properties of CuO nanoparticles was investigated and the antibacterial activity of the synthesized nanoparticles was studied by antibiofilm screening. The x-ray Powder Diffraction (XRD) patterns show the formation of a pure CuO phase with a good incorporation of Mg-dopant into the CuO lattice due to the comparable ionic radii of Cu2+ and Mg2+ ions. The Mg-dopant increases the crystallite size from 25 nm (at x = 0.000) to 28.12 nm (at x = 0.020). The Transmission Electron Microscope (TEM) images reveal the effect of Mg-doping on the morphology of CuO nanoparticles by decreasing their agglomeration, resulting in more uniform spherical-shaped nanoparticles. Energy Dispersive x-ray (EDX) and x-ray Photoelectron Spectroscopy (XPS) confirm the purity and the successful development of Mg-doped CuO nanoparticles. The changes in the characteristic vibrational modes of CuO are studied by Raman spectra, upon Mg-doping. Furthermore, the optical properties explored by Ultraviolet-Visible (UV–vis) spectroscopy reveal a redshift of the absorption peaks of CuO nanoparticles due to the Mg-doping. The energy gap (Eg) is affected by Mg-doping, where its broadening is attributed to the quantum confinement effect in CuO. The magnetic properties were investigated by Vibrating Sample Magnetometer (VSM) at room temperature. Cu1-xMgxO nanoparticles have combined paramagnetic and weak ferromagnetic behaviors. Besides, Cu1-xMgxO nanoparticles exhibited significant antibiofilm effects. These results highlight the potential use of Mg-doped CuO nanoparticles as antibiofilm agents.

Crystal structure, vibrational and chemical properties and phase transitions in Glycyl-DL-Aspartic acid and Glycyl-DL-Aspartic acid monohydrated.

In this paper, the structural and vibrational analysis of the dipeptides glycyl-DL- aspartic acid hydrate (H-Gly-DL-Asp-OH.H2O) crystal, with P1¯ (C11) triclinic symmetry and glycyl-DL- aspartic acid (H-Gly-DL-Asp-OH) crystal, with Cc space group (Cs4) monoclinic structure, were studied. The crystallographic structures of these molecules were determined by single-crystal X-ray diffraction. Changes in the powder X-ray diffraction patterns of H-Gly-DL-Asp-OH.H2O as a function of the temperature were recorded. After 403 K, the water molecule detaches itself from H-Gly-DL-Asp-OH.H2O, causing its symmetry to change from triclinic to monoclinic. The normal modes of vibration were analyzed through calculations based on Density Functional Theory (DFT) using the B3LYP functional with the Gaussian bases 6–311++G (d,p) and potential energy distribution (PED) analysis. These results, together with literature data and Raman and infrared (IR) spectroscopy measurements, allowed the identification of the various vibrational normal modes. Furthermore, the effect of high pressure on H-Gly-DL-Asp-OH.H2O was studied by Raman spectroscopy experiments. The results obtained from the Raman spectra at high pressures indicate changes around 2.1 and 4.5 GPa, such as the disappearance, splitting and emergence of some modes, as well as discontinuities in the evolution of wavenumbers of several normal modes of vibration. Such changes involved modes localized in the region of external modes, while others involved molecular backbone modes and modes that participate in hydrogen bonding. The changes were related to small conformational changes associated with H bonds and small deformations in hydrated dipeptide molecules.

Bystrite, Na7Ca(Al6Si6O24)S52–Cl–: formula redefinition and relationships with other four-layer cancrinite-group minerals

AbstractBystrite is redefined as a four-layer cancrinite-group mineral with the four-layer Losod-type framework and the end-member formula Na7Ca(Al6Si6O24)S52–Cl–. The mineral is known only at the Malo–Bystrinskoe gem lazurite deposit, Baikal Lake area, Siberia, Russia. The associated minerals are calcite, lazurite, sodalite, fluorapatite, phlogopite, diopside, dolomite and plagioclase. Bystrite is brittle, with the Mohs hardness of 5 and distinct cleavage on {10$\bar{1}$0}. The yellow colour of bystrite is due to the presence of S52– anions occurring in Losod (LOS) cages of the aluminosilicate framework with the ABAC stacking sequence. Measured and calculated density is, respectively, 2.43(1) and 2.412 g cm–3 for the holotype and 2.42(1) and 2.428 g cm–3 for the cotype sample. Bystrite is uniaxial (+), ɛ = 1.660(2) and ω = 1.584(2). The mineral was characterised by infrared and Raman spectra. The empirical formulae of the holotype and cotype samples are Na6.97K0.04Ca0.98(Si6.03Al5.97O24)(S52–)0.93[(SO42–)0.15Cl0.83] and Na6.75K0.04Ca1.11(Si6.09Al5.91O24)(S52–)1.04[(HS–)0.17Cl0.85], respectively. Bystrite is trigonal, space group P31c. The unit-cell parameters are: a = 12.8527(6) Å, c = 10.6907(5) Å, V = 1529.4(1) Å3 and Z = 2. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 4.821 (32) (102), 3.915 (38) (211), 3.712 (100) (300), 3.307 (50) (212), 2.782 (18) (400), 2.692 (22) (401), 2.673 (30) (004) and 2.468 (23) (402). Isomorphism and genesis of bystrite-type minerals is discussed. Bystrite and its K,HS-analogue sulfhydrylbystrite, Na5K2Ca(Al6Si6O24)S52–(HS)–, are indicators of highly reducing conditions.

Sericin mediated gold/silver bimetallic nanoparticles and exploration of its multi-therapeutic efficiency and photocatalytic degradation potential

The current investigation aimed at bimetallic gold-silver nanoparticles (Au/Ag NPs), here called BM-GS NPs, synthesis using sericin protein as the reducing agent in an easy, cost-effective, and sustainable way. The obtained BM-GS NPs were characterized by UV–Visible spectroscopy, Transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDS), atomic force microscopy (AFM), Dynamic light scattering (DLS) and Zeta potential, X-ray Powder Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and Thermogravimetric analysis followed by evaluation of its multitherapeutic and photocatalytic degradation potentials. The TEM analysis revealed its spherical nature and the EDS result displayed the presence of both Ag and Au elements, confirming the synthesis of BM-GS NPs. The XRD pattern verified the crystalline nature of the nanoparticles (NPs). The DLS analysis showed an average size of 86.08 d nm and the zeta potential showed a highly negative value (−26.3 mV) which specifies that the generated bimetallic NPs are stable. The BM-GS NPs exhibited positive wound healing potential (with 63.38% of wound closure rate at 25 μg/ml, as compared to 54.42% by the untreated control) with very negligible toxicity effect on the cell viability of the normal keratinocyte cells. It also demonstrated promising antioxidant properties with 65.00%, 69.23%, and 63.03% activity at 100 μg/ml concentration for ABTS (2, 2-azinobis) (3-ethylbenzothiazoline-6-sulfonic acid)), DPPH (1, 1 diphenyl-2-picrylhydrazyl) and SOD (superoxide dismutase enzyme) assays respectively, antidiabetic potential (with a significantly high α-glucosidase inhibition potential of 99.69% at 10μg/ml concentration and 62.11% of α-amylase enzyme inhibition at 100 μg/ml concentration) and moderate tyrosinase inhibitory potential (with 17.09% at 100 μg/ml concentration). Besides, it displayed reasonable antibacterial potential with the diameter of zone of inhibition ranging between 10.89 and 12.39 mm. Further, its antibacterial mode of action reveals that its effects could be due to being very smaller, the NPs could have penetrated inside the cellular membrane thereby causing rupture and damage to the interior materials leading to cellular lysis. The photocatalytic evaluation showed that synthesized BM-GS NPs have the efficiency of degrading methylene blue dye by 34.70% within 3 h of treatment. The above findings revealed the multi-therapeutic efficacy of the sericin globular protein-mediated BM-GS NPs and its potential future applications in the cosmetics and food sector and environmental contamination management industries.

Ternary orthorhombic Laves phases Sr2Pd3Sn, Eu2Pd3Sn and Eu2Pd3In

Abstract The ternary Laves phases Sr2Pd3Sn, Eu2Pd3Sn and Eu2Pd3In were synthesized by induction melting of the elements in sealed tantalum ampoules. The polycrystalline products were characterized through their powder X-ray diffraction patterns. The structure of Eu2Pd3Sn was refined from single crystal X-ray diffractometer data: Mg2MnGa3 type, Cmcm, a = 583.36(5), b = 908.31(7), c = 958.06(8) pm, wR2 = 0.0366, 557 F 2 values, 23 variables. The palladium and tin atoms show the inverse coloring on the network of condensed tetrahedra of Mg2MnGa3, i.e., MnGa3 versus Pd3Sn. Refinement of the occupancy parameters revealed small defects for the europium site, leading to composition Eu1.962(6)Pd3Sn for the studied crystal. Sr2Pd3Sn is a Pauli paramagnet and Eu2Pd3Sn shows Curie-Weiss paramagnetism (7.86(1) µB Eu atom−1 and Θ P = 48.1(1) K). Ferromagnetic ordering is observed below T C = 46.1(1) K. The 119Sn and 151Eu Mössbauer spectra of Sr2Pd3Sn and Eu2Pd3Sn are discussed with respect to electron density changes as a function of the tin content and the ionicity in the sequence of the stannides Sr2Pd3Sn/Eu2Pd3Sn → Sr2Pd2Sn/Eu2Pd2Sn → EuPdSn → EuPdSn2.

Photocatalytic dye degradation activities of green synthesis of cuprous oxide nanoparticles from Sargassum wightii extract

In the present study, we report on the green synthesis of cuprous oxide (Cu2O) nanoparticles using Sargassum wightii by single-step straightforward co-precipitation method. The preparation of Cu2O nanoparticles is a fully green and environmentally beneficial process. The samples exhibit a homogeneous distribution and a uniform spherical shape and the size ranged between 20 and 30 nm, according to studies using the Field emission scanning electron microscope (FESEM). The existence of elements, Cu (42.09%) and O (57.91%), was confirmed by EDAX analysis. The X-ray Powder Diffraction (XRD) pattern supports the polydispersity and crystalline structure of the material. The presence of metal oxide functional groups was proven using Fourier-transform infrared spectroscopy(FTIR). The optical band gap of the Cu2O is estimated to be about 3.11 eV based on the optical transmission at 383 nm using frequently used ultraviolet spectra. The photocatalytic degradation ability of the as-prepared sample was investigated against the methylene Blue (MB), methylene Orange (MO), and Rhodamine B (RB) dye under UV, and sunlight irradiation. According to the photocatalytic degradation analysis, the green synthesized Cu2O nanoparticles show high photocatalytic degradation of methylene Orange 92% after 180 min under Sunlight irradiation. Cuprous oxide nanoparticles are an efficient activity that is advantageous to water purification and environmentally favourable applications.

Eu2+/Ce3+-doped NaAlSiO4 selective occupation-induced emission structure unit evolution and its luminescence characteristics

NaAlSiO4: xEu2+,yCe3+ blue-red phosphors were prepared by high-temperature melting-icy quenching-heat treatment. The effects of emission structure unit evolution, microstrain, microcrystalline size and selective occupation on the luminescence characteristics of the prepared phosphor were systematically studied by powder X-ray diffraction pattern (XRD) and photoluminescence spectroscopy (PL). In the structure of NaAlSiO4: 2%Eu2+, 2%Ce3+ hexagonal crystalline sodium nepheline, Eu2+ ions occupy the Na+ (II) position to form a EuNa+(II)2+ luminescent structure unit, and Ce3+ ions occupy the Na+ (I) position to form a CeNa+(I)3+ luminescent structure unit. The NaAlSiO4: 2%Eu2+/NaAlSiO4: 2%Ce3+ emits 555 nm yellow-green light/395 nm blue-violet light under the excitation of 354 nm/298 nm, respectively, which is derived from the 5d-4f transition of Eu2+ and Ce3+. There is energy transfer of Ce3+→Eu2+ in the sodium nepheline matrix, of which the transport pathway is m EuNa+(II)2+ ←O←n CeNa+(I)3+ →O→m EuNa+(II)2+, and the transport mechanism is electric quadrode-electric quadrupole interaction, and the energy transfer efficiency reaches 98.6%. The sodium nepheline NaAlSiO4: 2%Eu2+, 2%Ce3+ phosphor with energy level barrier 0.386 eV, possesses good thermal stability. This single-phase aluminosilicate multicolor phosphor has potential application value for WLED illumination and PDP display.

Phosphotungstic acid immobilized over SnO2 mesoporous material as a heterogeneous catalyst for fructose to 5-hydroxymethylfurfural conversion

5-Hydroxymethylfurfural (HMF) is regarded as an essential platform chemical due to its flexible nature that could be converted into a variety of value-added compounds including production of liquid fuels and fine chemicals. We have developed a phosphotungstic acid (PTA) immobilized over SnO2 mesoporous material by hydrothermally employing Pluronic P123 as a structure directing agent (SDA) to obtain a heterogeneous catalyst for fructose to HMF conversion, and the catalyst is designated as MSnPTA. The powder X-ray diffraction patterns in low angle region, type IV isotherm and fringes of the catalyst confirmed the mesoporosity of the material. The catalyst is comprised of BET surface area of 85.86 m2/g and average pore diameter of 7.9 nm. Spherical shape through worm like structure formed small particles facilitated the large surface area of the MSnPTA catalyst that prefer to occur the catalytic reaction. The uniform elemental distribution of PTA over SnO2 ascribed more active sites, resulting in high acidity of the catalyst as measured by TPD of ammonia, which increased the conversion of fructose to high yield of HMF in a short reaction time. The yield of the HMF increased as increasing the amount of catalyst and temperature as expected.

Pressure/Thermo-Induced Hypsochromic-Shifted and Enhanced Luminescence Based on Carbazole Emitter

Most organic mechanochromic luminogens show bathochromic-shifted and quenched emission with increasing pressure. Design of turn-on mechanochromic material with hypsochromic-shifted luminescence is still a challenge. Herein, a novel emitter (namely DCzPy) was prepared through laboratory-synthesized carbazole to study its stimuli-responsive luminescence. The crystalline powders of DCzPy emitted blue-green fluorescence at 490 nm. Upon gently grinding, the fluorescence intensity of DCzPy was dramatically enhanced with a hypsochromic shift by 33 nm. Further heavily grinding, its emission wavelength returned to 490 nm. Powder X-ray diffraction patterns indicated that such behaviors were attributed to the solid-state morphology transition from crystal to crystal. Interestingly, a large bathochromic-shifted and weakened fluorescence was achieved under isotropic compression. Moreover, thermoresponsive behavior of DCzPy was studied in the film to find that its emission turned from green to blue as the temperature increased. Given the thermo-induced fluorescence switching of DCzPy, a two-dimensional code was fabricated for information anticounterfeiting.

Structural Characterization of Pharmaceutical Cocrystals with the Use of Laboratory X-ray Powder Diffraction Patterns

X-ray powder diffraction is a vital analytical tool that is used in pharmaceutical science. It is increasingly used to establish the crystal structure of a new pharmaceutical substance, in particular, cocrystal or its polymorphic forms. This review begins with a brief discussion of the reliability of the structural parameters retrieved from powder patterns. Recent examples of the successful determination of crystal structures of pharmaceutical cocrystals and salts from powder diffraction data are discussed. These examples show the increased capabilities of laboratory X-ray powder diffractometers and modern software in solving actual problems of pharmaceutical science.

Novel solution combustion synthesis of CeO2/CuO nanocomposite for photocatalytic and biological applications

In this study, CeO2/CuO nanocomposite (NC) were prepared by the novel solution combustion technique using urea as a fuel. The as-synthesized materials were characterized by XRD, FT-IR, UV–Vis spectroscopy, and PL. The surface morphology and the elemental composition of the CeO2/CuO NC were investigated by FE-SEM and EDAX respectively. The powder X-ray diffraction (XRD) patterns confirm the cubic and monoclinic phases for CeO2 and CuO. The average crystallite sizes were calculated to be 5.16 nm, 13.87 nm, and 10.36 nm for CeO2, CuO, and CeO2/CuO NC respectively. The FTIR analysis confirmed the existence of metal-oxygen stretching and other bonds present in the prepared samples. The band gap values were determined to be 2.43 eV, 3.02 eV, and 1.87 eV for CeO2, CuO, and CeO2/CuO NC respectively. The various emission peaks from the photoluminescence spectra correspond to UV emission attributed to the recombination of electron-hole pairs in free excitons.FE-SEM images of the synthesized CeO2/CuO NC showed a roughly stacked and clustered surface morphology. EDAX spectrum confirmed the presence of Ce, Cu, and O in the synthesized CeO2/CuO NC. The antimicrobial assay showed significant toxicity against both gram-positive and gram-negative bacteria. The photocatalytic activity of the as-synthesized CeO2/CuO NC was investigated by photodegradation of the organic dye methylene blue under visible light irradiation.

Biogenic synthesis of selenium nanoparticles using Hibiscus esculentus L. extract: Catalytic degradation of organic dye and its anticancer, antibacterial and antifungal activities

In this work, we develop the synthesis of selenium nanoparticles (B@SeNPs) using a green method using the aqueous extract of Hibiscus esculentus L. Various techniques were used to characterize bio-synthesized B@SeNPs. The mixture color was clearly changed to reddish at 45-50 °C and the extract pH = 6. According to Fourier transform infrared spectroscopy (FT-IR), the B@SeNPs were produced, capped, and stabilized using biomolecules found in plant extracts. The energy dispersive X-ray (EDX) analysis profile revealed an atomic Se signal (1.39 mV). The powder X-ray diffraction (PXRD) pattern confirmed the hexagonal phase crystalline form of B@SeNPs. The zeta potential for SeNPs was determined to be -51.3 mV. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) micrographs revealed spherical Se particles with sizes of roughly 62 nm. Furthermore, B@SeNPs can degrade methylene blue dye by 98.3% at 21 min with a rate constant of 0.1023 min-1 in the presence of NaBH4. In biological evaluation, the synthesized nanoparticles have been proven to be effective against two human cancers (AGS and MCF-7 cells) with IC50 values of 20.46 and 88.43 µg/mL, respectively. Additionally, B@SeNPs showed high safety in the Beas cell line (normal) at 123 µg/mL as the highest concentration. The biofabricated SeNPs had a moderate antibacterial effect against ATCC and multidrug-resistant clinical isolates. They had no antifungal activity against the tested fungus strains except C. albicans (IFRC 1873), with a MIC value of 138.75 µg/mL. Finally, the green-synthesized B@SeNPs could be a contender for further testing as a chemotherapeutic agent in the treatment of some human cancers.

Synthesis and Characterization of Silicoaluminophosphate CIT-16P and Its Transformation to SAPO-17

A silicoaluminophosphate molecular sieve, CIT-16P, is synthesized using butane-1,4-bis(quinuclidinium) [(C7H13N)-(CH2)4-(NC7H13)]2+ dihydroxide (DiQ-C4-(OH)2) as an organic structure-directing agent (OSDA). Upon the removal of the OSDA, either by thermal treatment in air at temperatures exceeding 490 °C or by extended ozone treatment at 150 °C, CIT-16P transforms to SAPO-17 (ERI topology). The structure solution of CIT-16P in its as-synthesized form is obtained using a Rietveld refinement of the powder X-ray diffraction pattern. The primary composite building units (CBUs) of CIT-16P are highly distorted cancrinite (can) CBUs that transform into stable can units of the ERI-type framework as a result of the OSDA removal. The distortion of can CBU is maintained without transformation by the presence of tightly bound DiQ-C4 dications in the as-synthesized form of CIT-16P. The transformed material is characterized and evaluated as a catalyst in the methanol-to-olefins (MTO) reaction. The catalytic behavior of the formed SAPO-17 (Si/T-atom = 0.022) (T = Si + Al + P) at 400 °C and WHSV of 1.3 h-1 produces elevated C3+ olefin products (i.e., propylene, butenes, and pentenes) in early stages of the reaction. However, as the reaction proceeds, the C3+ fraction decreases in favor of more ethylene.

Crystal Structure L-Asparagine Potassium Nitrate Single Crystals

The elemental analysis of the compound confirms the ratio of the compound. The sharp and well defined Bragg peaks obtained in the powder X-ray diffraction pattern confirm the crystalline nature of the compound. The single crystal unit cell parameters of the compound show that the grown crystal belongs to orthorhombic system with space group P. The optical property of the compound was ascertained through UV-visible spectral analysis. The various characteristics absorption bands in the compound were assigned through Fourier transform infra-red (FTIR) spectroscopy. Thenonlinear optical property study indicates that the compound has SHG efficiency 0.50 times greater than that of standard potassium dihydrogen phosphate (KDP).