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We synthesized the Lu 2 CoCrO 6 compound, multiferroic member of double perovskite system, by sol–gel method and then investigated the crystal structure, magnetization, magnetocaloric effect (MCE), and electrical polarization study. The analysis of powder x-ray diffraction pattern confirms that the monoclinic crystal structure with P2 1 /n space group is better fitting for the Lu 2 CoCrO 6 compound. Distribution between Co and Cr ions at the B-site is not perfectly ordered. Partial ordering between these B-site cations leads to a certain degree of disorder due to the presence of antisite defects and antiphase boundaries. These anti-site disorders (in the B-site) generate various fascinating magnetic phenomena. Although the temperature dependent inverse susceptibility plot shows predominant antiferromagnetic ground state in this system, simultaneously, a second order magnetic phase transition was observed from the Arrott plot. Moreover, the isothermal magnetization study confirms the coexistence of antiferromagnetic (AFM) and ferromagnetic (FM) phases below the transition temperature. The investigation of the magnetocaloric effect shows that the AFM phase of the system converts into the FM phases above critical field values. However, the breakdown of universal behavior of MCE in the paramagnetic region confirms the coexistence of the AFM phase as a secondary phase within the FM matrix. In addition, at lower temperatures, we observe a clear and well-defined ferroelectric hysteresis loop, suggesting ferroelectricity in the material. From these results, we conclude that Lu 2 CoCrO 6 is a multiferroic material in which the coexisting magnetic and multiferroic phases appear to be correlated and weak magneto-electric coupling was also observed. Furthermore, our experimental results help to encourage basic fundamental as well as applied research on rare-earth and transition metal based double perovskite systems due to their complex exchange interaction and multiferroic behavior. [ABSTRACT FROM AUTHOR]

Temperature dependent bonding behavior plays a significant role in deciding properties of high temperature ceramics like boron carbide. However, few studies to date have addressed the physical properties of this class of materials with respect to their temperature dependent bonding nature. In addition, materials with the flexibility to accommodate variations in interatomic bonding and lattice vibrations over a wide range of temperatures are less known. In this work, temperature dependent structural analyses of carbon-rich boron carbide microflakes using in situ powder x-ray diffraction techniques (up to 1000 °C) supported by transmission electron microscopy measurements reveal that while most bonds in the rhombohedral structure increase in length with temperature; there is no change in certain bond lengths. However, there is an unusual decrease in length (∼1.03%) of the inter-cluster –C–(central boron)BC–C– without any polyhedral redistribution. This is accompanied by an increase in lattice vibrations without significant alteration to the crystal structure over the wide temperature range studied. Temperature dependent micro-Raman experiments further confirmed the above observations. The above bonding behavior could be directly correlated to the trends in reported results of high temperature conductivity via the model of hole hopping through specific atomic positions of the rhombohedral framework, thus opening the scope to investigate structure–property relationships in high temperature functional materials. [ABSTRACT FROM AUTHOR]

The x-ray restrained wave function (XRW) method is a quantum crystallographic technique to extract wave functions compatible with experimental x-ray diffraction data. The approach looks for wave functions that minimize the energies of the investigated systems and also reproduce sets of x-ray structure factors. Given the strict relationship between x-ray structure factors and electron distributions, the strategy practically allows determining wave functions that correspond to given (usually experimental) electron densities. In this work, the capabilities of the XRW approach were further tested. The aim was to evaluate whether the XRW technique could serve as a tool for suggesting new exchange-correlation functionals for density functional theory or refining existing ones. Additionally, the ability of the method to address the influences of the crystalline environment was also assessed. The outcomes of XRW computations were thus compared to those of traditional gas-phase, embedding quantum mechanics/molecular mechanics, and fully periodic calculations. The results revealed that, irrespective of the initial conditions, the XRW computations practically yield a consensus electron density, in contrast to the currently employed density functional approximations (DFAs), which tend to give a too large range of electron distributions. This is encouraging in view of exploiting the XRW technique to develop improved functionals. Conversely, the calculations also emphasized that the XRW method is limited in its ability to effectively address the influences of the crystalline environment. This underscores the need for a periodic XRW technique, which would allow further untangling the shortcomings of DFAs from those inherent to the XRW approach. [ABSTRACT FROM AUTHOR]

We have investigated pressure-induced amorphization (PIA) of an alcohol clathrate hydrate (CH) of cubic structure type I (sI) in the presence of NH4F utilizing dilatometry and x-ray powder diffraction. PIA occurs at 0.98 GPa at 77 K, which is at a much lower pressure than for other CHs of the same structure type. The amorphized CH also shows remarkable resistance against crystallization upon decompression. While amorphized sI CHs could not be recovered previously at all, this is possible in the present case. By contrast to other CHs, the recovery of the amorphized CHs to ambient pressure does not even require a high-pressure annealing step, where recovery without any loss of amorphicity is possible at 120 K and below. Furthermore, PIA is accessible upon compression at unusually high temperatures of up to 140 K, where it reaches the highest degree of amorphicity. Molecular dynamics simulations confirm that polar alcoholic guests, as opposed to non-polar guests, induce cage deformation at lower pressure. The substitution of NH4F into the host-lattice stabilizes the collapsed state more than the crystalline state, thereby enhancing the collapse kinetics and lowering the pressure of collapse. [ABSTRACT FROM AUTHOR]

Developing highly efficient methane (CH4) hydrate storage methods and understanding the hydrate dissociation kinetics can contribute to advancing CH4 gas storage and transport. The effects of tetrabutylammonium bromide (TBAB) (a thermodynamic promoter) addition on the kinetics of CH4 hydrate were evaluated on the microscopic scale using synchrotron x-ray computed tomography (CT) and powder x-ray diffraction. Microscopic observations showed that a 5 wt. % TBAB solution facilitated the nucleation of CH4 hydrate owing to the initial growth of TBAB semi-clathrate hydrate particles. The CH4 hydrate crystals in the CH4 + TBAB hydrate sample were sponge-like with many internal pores and exhibited slightly enhanced self-preservation compared to the pure CH4 hydrate, both in the bulk and after pulverization to a fine powder. This study demonstrates the feasibility of controlling the rate of CH4 hydrate formation and preservation by using aqueous TBAB solutions in CH4 hydrate formation. [ABSTRACT FROM AUTHOR]

In this work, we report a high-pressure study on fergusonite-type LaNbO4. Powder x-ray diffraction and Raman spectroscopic experiments support the occurrence of a phase transition between 11 and 14 GPa. The transition takes place from a monoclinic fergusonite-type structure (space group I2/a) to another monoclinic structure (space group P21/c). The phase transition is reversible, and the high-pressure phase is isomorphic to the high-pressure phase of HoNbO4. The high-pressure phase remains stable up to 33.3 GPa, the highest pressure reached in the present measurements. Density-functional theory calculations found that in the pressure range of the studies; the high-pressure phase has a higher enthalpy than the low-pressure fergusonite phase. We propose that the high-pressure phase is metastable and it is observed because of non-hydrostatic conditions in the experiments. The pressure dependence of unit-cell parameters of the low-pressure phase and the room-temperature equation of state are reported. The pressure dependence of various Raman and IR frequencies as obtained from experiment and theory is also reported. For the fergusonite phase, we have also obtained the isothermal compressibility tensor, elastics constants, and elastic moduli. [ABSTRACT FROM AUTHOR]

Chemical pressure is widely applied to antiferroelectrics (AFEs) as a criterion to enhance their antiferroelectricity. However, NaNbO3 (NN)-based ceramic with well-defined double polarization hysteresis (P–E) loops was rarely reported based on this strategy, and the effect of chemical pressure on antiferroelectricity remains to be understood. In this work, the Me cations (Me is Ti, Sn, Zr) with different ionic radii were introduced into the component system 0.76NaNbO3–0.20AgNbO3–0.04CaMeO3 to tune the negative chemical pressure and investigate its effect on antiferroelectricity. The enhancement of negative chemical pressure can effectively stabilize the AFE phase and reduce hysteresis, as revealed by the P–E loops and dielectric properties, which is further confirmed by the change in crystal lattice parameters and in situ Raman spectra. Rietveld refinement of x-ray powder diffraction reveals that the enhanced negative chemical pressure mainly reduces the cation off-centering displacement and [BO6] octahedral tilting angles. As a result, the 0.76NaNbO3–0.20AgNbO3–0.04CaZrO3 exhibits good reversibility of the electric field-induced antiferroelectric–ferroelectric phase transition and well-defined double P–E loops. This work reveals the underlying mechanism of chemical pressure and provides an effective way of discovering new NN-based AFEs. [ABSTRACT FROM AUTHOR]

This study explores the nature, dynamics, and reactivity of the photo-induced charge separated excited state in a Fe3+-doped titanium-based metal organic framework (MOF), xFeMIL125-NH2, as a function of iron concentration. The MOF is synthesized with doping levels x = 0.5, 1 and 2 Fe node sites per octameric Ti-oxo cluster and characterized by powder x-ray diffraction, UV-vis diffuse reflectance, atomic absorption, and steady state Fe K-edge X-ray absorption spectroscopy. For each doping level, time-resolved X-ray transient absorption spectroscopy studies confirm the electron trap site role of the Fe sites in the excited state. Time scan data reveal multiexponential decay kinetics for the charge recombination processes which extend into the microsecond range for all three concentrations. A series of dye photodegradation studies, based on the oxidative decomposition of Rhodamine B, demonstrates the reactivity of the charge separated excited state and the photocatalytic capacity of these MOF materials compared to traditional heterometal-doped semiconductor photocatalysts. [ABSTRACT FROM AUTHOR]

Eutectic systems design requires an in-depth understanding of their solid–liquid equilibria (SLE). Modeling SLE in eutectic systems has as prerequisites, the melting properties and activity coefficients of components in the liquid phase. Thus, due to the unavailable melting properties of thermally unstable substances, it is impossible to estimate their activity coefficients from experimental SLE data and model the SLE phase diagram of their eutectic systems. Here, we evaluate the activity coefficients of thermally unstable constituents in the liquid phase, which were calculated independent of their melting properties by correlating the SLE data of their cocrystals. Differential scanning calorimetry and powder x-ray diffraction were employed to obtain the SLE phase diagram of three eutectic systems, i.e., tetramethylammonium chloride/catechol, tetraethylammonium chloride/catechol, and betaine/catechol systems, and identify the formation of nine cocrystals. The non-random, two-liquid equation was used to calculate the activity coefficients of the components in the liquid phase. The substantial negative deviation from ideality in the three studied systems indicated strong hydrogen bonding interactions in the liquid solution. Furthermore, modeling ion–ion interactions in eutectic systems containing ionic constituents is of utmost importance for understanding their nonideality. [ABSTRACT FROM AUTHOR]

CO gas sensing properties of 1-D ZnO nanostructures deposited on films of Multi-Wall carbon nanotubes were investigated using a vapor transport approach. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, energy dispersive X-ray, Raman spectroscopy, diffused reflectance spectroscopy, and photoluminescence, techniques were used to carry out the structural, morphological, and optical characterizations. The development of carbon-doped hybrid MWCNTs/ZnO nanostructures was demonstrated by the current results. The synthesized nanostructures were dense tapering belts and pedal-like crystalline structures as evidenced by their structural and morphological characteristics. Multiple networks of pure ZnO and hybrid MWCNTs-ZnO nanostructures were used to synthesize the gas sensors. Doped ZnO nanostructures sensing technique for CO gas detection was investigated in the present study. The combined impact of ZnO and MWCNTs was shown to be beneficial in boosting the response towards CO gas, as the response to CO gas at a concentration of 20 parts per million (ppm) was found to be five-times greater than that of ZnO sensors with good stability. [Display omitted] [ABSTRACT FROM AUTHOR]

This study explores the synthesis of La 10 Si 6 O 27 :Sm3+ nanoparticles (LSNP) with varying samarium (Sm3+) concentrations (0–8 mol%) using eco-friendly solution combustion method with urea as a fuel. Using powder X-ray diffraction (PXRD), we determined that the nanoparticles typically measure between 15 and 17 nm and display a spherical morphology. These rare earth (RE)-doped nanoparticles were employed as a novel photocatalyst for the degradation of malachite green (MG) dye, exhibit unprecedented photocatalytic efficiency. The release of OH radicals during the degradation process was found to vary with the chemical structure and concentration of the photocatalyst, with the 6 mol% LSNP formulation showing a significant advancement under both UV and sunlight. Electrochemical assessments revealed that these nanoparticles exhibit excellent cyclic stability and robust performance. Notably, the specific capacitance of the nanoparticles increased with the samarium concentration, reaching a peak of 261.3 F/g in 0.1 M HCl. Furthermore, graphite-modified electrodes incorporating these nanoparticles showed significant potential as sensitive materials for detecting mercury and lead in concentrations as low as 1–6 mM, underscoring the versatility and functional adaptability of the synthesized nanoparticles in environmental and electrochemical applications. The prepared La 10 Si 6 O 27 :Sm3+ nanoparticles The nanoparticles demonstrated an optimal photocatalytic efficiency of 95.5 % under UV light and 88.15 % under sunlight at 6 mol% Sm3+ doping. Additionally, a peak specific capacitance of 261.3 F/g was achieved in 0.1 M HCl. [ABSTRACT FROM AUTHOR]

Powder nanoparticles of ZnO/Fe 2 O 3 composites with varying concentrations of precessour have been synthesized with the help of the co-precipitation method followed by annealing and milling the composite at 700 °C. Then, the obtained powder composites were characterized by X-ray diffraction, Fourier Transformation Infrared spectroscopy, Field Emission Scanning electron microscopy with EDX, Raman spectroscopy, UV–visible absorption spectroscopy, and Photolumnisences. The powder X-ray diffraction results show the formation of the well-crystalline phase of ZnO/Fe 2 O 3. For the further study of the structural analysis, we have done the Rietveld refinement of the XRD data. Williams-hall plot was used to calculate the lattice strain of the composites. Crystalline size, dislocation density, and Rietveld parameters were also calculated using the XRD and Rietveld refinement methods. FESEM study revealed that with an increase in the concentration of Fe 2 O 3 , the shape of the composite changes from spherical to nanosheets via nanorods. The absorption peaks and vibration band obtained at zftir and RAMAN spectra show the formation of the ZnO/Fe 2 O 3. The UV–visible absorption spectroscopy shows the maximum absorption peak in the 200–400 nm range. The successfully synthesized nanocomposites ZnO/Fe 2 O 3 indicate that it can be a potential candidate for organic pollutant degradation. [ABSTRACT FROM AUTHOR]

Oxalyldihydrazide (ODH) and coffee extracted fuel (CEF) were used to synthesize Ceria (CeO 2) nanoparticles by solution combustion synthesis route. The cubic fluorite structure, crystalline nature, crystallite size and particle size of ceria nanoparticles were confirmed using the powder X-ray diffraction (PXRD) and High-Resolution Transmission Electron Microscope patterns respectively. Field Emission Scanning Electron Microscope (FESEM) images were used to understand the Surface morphology of the synthesized samples. Based on XRD results the volume of coffee husk extract for the optimum phase formation is found to be 40 mL. The fluorite structure of the samples and the presence of oxygen vacancies in the samples were confirmed from the Raman spectral analysis. ESR (Electron Spin Resonance) studies confirmed formation of relatively more intrinsic defects in CEF-ceria nanoparticles compared to ODH-ceria nanoparticles. The semiconducting nature of the synthesized samples was confirmed by analysing UV–visible absorbance spectra. The functional group confirmation was obtained by analysing Fourier Transform Infrared (FTIR) spectra of both the samples. AC conductivity and dielectric relaxation studies of the samples in pellet form were carried out over a wide frequency (20Hz–10 MHz) and temperature (200–640 °C) range using a precision impedance analyser. A higher value of dielectric constant was observed for CEF-ceria nanoparticles. [ABSTRACT FROM AUTHOR]

Sm3+ doped β-wollastonite (β-CaSiO 3) nanoparticles (β-CSO:Sm3+ NPs) are effectively synthesized through agricultural waste. Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), photoluminescence (PL), and electrochemical analyses are utilized to validate the synthesis, structural, luminescence, and supercapacitor characteristics of the NPs. The diffraction analysis unveiled a monoclinic crystal structure nested within a rhombohedral lattice system in the synthesized samples. The excitation spectrum of β-CSO doped with 7 mol % of Sm3+ ions exhibited a prominent peak at 404 nm, while the emission spectrum revealed four distinct peaks. The most intense emission peak, observed at 645 nm, corresponds to the radiative transition from 4G 5/2 to 6H 9/2 states of Sm3+ ions. Analysis of emission spectra across different doping concentrations identified 7 mol % as the optimal optical doping concentration. The phenomenon of concentration quenching is attributed to dipole-dipole interactions. Exploration into energy storage and biosensor technologies is crucial for addressing societal challenges, expanding scientific understanding, and promoting sustainable progress across various domains including energy and healthcare. In this investigation, we successfully synthesized pristine RGO@β-CSO:Sm3+ nanocomposites (NCs) using a hydrothermal approach. Through cyclic voltammetry (CV) analysis, it is observed that these NCs exhibited markedly higher specific capacitance (C sp) of 152.15 F/g at a scan rate of 2 mV/s. Moreover, they demonstrated a notable energy density of 35.77 Wh/kg, alongside enhanced capacity retention of 82.27 % and exceptional Coulombic efficiency of 95.77 % compared to undoped RGO@β-CSO. Subsequently, these NCs are utilized to fabricate modified carbon paste electrodes (MCPE) for electrochemical dopamine (DA) detection at an optimal pH of 7.4. The modified electrodes demonstrated favorable current responses for DA voltammetry, achieving low limits of detection (LOD) and quantification (LOQ) values of 9.226 μM and 30.75 μM, respectively. Additionally, they showcased improved selectivity between dopamine and uric acid, with a deterioration rate of only 97.83 % over 20 cycles. These findings suggest that the developed electrode holds significant promise for applications in supercapacitors and dopamine detection, thereby contributing to advancements in energy storage technology and biosensor applications. [Display omitted] • Economically feasible, reduced graphene oxide based β-CaSiO 3 :Sm3+ nanocomposites are synthesized from agricultural and food waste materials. • Structural, morphological, luminescence and electrochemical studies are performed using XRD, FE-SEM, TEM, XPS, PL, I QE CH instruments. • Electrochemical studies of synthesized RGO@β-CaSiO 3 :Sm3+ nanocomposites were performed to evaluate parameters like specific capacitance, energy density, coulombic efficiency, capacity retention etc. • Biosensor studies of the synthesized materials, using dopamine and uric acid proves to be a boon for biomedical applications. • Reduced graphene oxide based β-CaSiO 3 :Sm3+ nanocomposite can be used for future technologies, particularly in wearable/integrated electronic devices, smart sensor opto-electronic devices. [ABSTRACT FROM AUTHOR]

The present work reports a synthesis of octahedron (A55NO) and cube-shaped (A55NC) Mn 0.5 Zn 0.5 Fe 2 O 4 ferrite nanoparticle dispersion in distilled water. The crystal structure analyzed using powder X-ray diffraction (XRD) shows the crystallite sizes of 17.7 ± 0.4 nm and 11.9 ± 1.0 nm, respectively, for the A55NO and A55NC particles. The morphology as seen from transmission electron microscopy (TEM) confirms 17.8 ± 0.3 nm (σ = 0.27) and 8.7 ± 0.3 nm (σ = 0.33) edge lengths, respectively, for octahedron and cube-shaped particles. The thermogravimetric analyzer (TGA) and Fourier transform infrared (FTIR) spectroscopy are used to confirm the chemical binding of the surfactant with a sharp transition at 208.67 °C and 218.32 °C, respectively, for octahedron and cube-shaped particles, indicating the removal of the surfactant due to its decomposition from the particle surface. Both the particles are highly magnetic and have 75.32 Am2/kg and 72.93 Am2/kg saturation magnetization, as revealed by their M − H loops using a vibrating sample magnetometer (VSM). The stability of the sample is confirmed using the particle size analyzer (DLS) and the Zeta potential analyzer. The induction heating capacity of the fluid was investigated using the Embrell Easy Heat model LA6310 at 330 kHz. The heating response shows that even a minimum concentration of 1 mg/mL is sufficient to achieve the hyperthermic window temperature of 42 °C for both samples, which, unlike the same composition prepared by other routes, makes it impossible to go beyond 38 °C. Moreover, octahedron particle dispersion can reach this window temperature within 10 min, whereas cube particle dispersion requires only 15 min. The findings of this study hold significant practical value since it confirms that Mn 0.5 Zn 0.5 Fe 2 O 4 composition with tuneable shape has the potential to work as a temperature-controlled magnetic switch for magnetic fluid hyperthermia under the defined safety limit with the minimum concentration. [ABSTRACT FROM AUTHOR]

This study investigates the thermal behavior and structural transitions of silver vanadate microrods (AgVO 3) synthesized via coprecipitation. The samples were characterized at room temperature using scanning electron microscopy, Powder X-ray Diffraction, and Raman scattering. The AgVO 3 was obtained in the monoclinic phase (β-phase) with a Cm space group and rod-like morphology of micrometer-sized diameter. In situ temperature-dependent studies utilizing XRD and Raman spectroscopy revealed notable findings: at low temperatures (298–12 K), the β-AgVO 3 phase exhibited thermal stability alongside uniaxial negative thermal expansion (NTE) along the b lattice parameter of microcrystals. Conversely, experiments at high temperatures (298–673 K) demonstrated a reversible structural transition from the monoclinic phase to a triclinic phase at 473 K (β → β'), with NTE observed along the b direction in both high-temperature phases. These temperature-induced structural modifications and the observed uniaxial negative thermal expansion in β-AgVO 3 microrods constitute significant contributions to the field, providing valuable insights into their thermal behavior and potential applications. • Temperature-dependent behavior of silver vanadate (β-AgVO 3) microrods using in situ XRD and Raman scattering. • β-AgVO 3 microrods present reversible monoclinic to triclinic phase transitions at high temperatures. • The β-AgVO 3 microrods exhibit uniaxial negative thermal expansion along the b-axis at low and high temperatures. [ABSTRACT FROM AUTHOR]

Doped cerium oxides are technologically relevant materials and used as electrolytes in intermediate temperature solid oxide fuel cells. An important issue for these materials is the reduction of ceria at low oxygen partial pressures which leads to mixed ionic electronic conduction. In the present work, reduction behaviour in Ce 0.8 Nd 0.2 O 1.9-δ is examined under inert and strongly reducing conditions. Even under inert conditions, ca. 3.5 % of the Ce is redox active up to around 800 °C, which appears to be correlated with non-linear behaviour in the Arrhenius plot of conductivity and thermal expansion of the lattice. Under more strongly reducing conditions, a secondary partial reduced phase is formed related to triclinic Ce 11 O 20 , which introduces significant electronic conductivity into the system. The dynamics of the re-oxidation process are examined using X-ray powder diffraction and electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Ce-doped WO3 nanoparticles were fabricated and characterized using powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR), Raman, SEM–EDX, UV–Vis, photoluminescence (PL), dynamic light scattering (DLS), and X-ray photoelectron spectroscopy (XPS) analyses. The results revealed the formation of a highly crystalline monoclinic phase in Ce-doped WO3 photocatalyst (abbreviated WCC), confirmed by Raman spectroscopy. The bandgap was tuned by increasing the percentage of Ce dopant, where the WCC (1 mol wt% Ce-doped WO3) photocatalyst sample exhibited the highest photocatalytic activity towards synthetic methylene blue (MB) dye pollutant and biodegradation-resistant tetracycline hydrochloride (TC-HCl) antibiotic. The decomposition efficiency using the WCC photocatalyst against aqueous MB dye and TC-HCl antibiotic reached 95% and 51% after exposure to simulated sunlight irradiation for 180 min, with excellent stability after four recycling runs. The interfacial contact between Ce and WO3 effectively shortened the charge transfer carrier process, enabling redox reactions to provide the best decomposition efficiency over the investigated pollutants. The photodecomposition rate constant of WCC was 0.017 min−1 for MB dye, which is 3.6-fold higher performance than common literature photocatalysts. The results showed the significance of the environmental impact toxicity assessment by applying the treated water to finger millet plant growth. Based on the research feasibility, the synthesized photocatalyst demonstrated superior decomposition against dyes and antibiotics, making it highly suitable for applications in wastewater treatment. Moreover, the use of degraded water resulted in productive plant growth. [ABSTRACT FROM AUTHOR]

The off-target effects of herbicides present significant challenges in agricultural practices, posing serious threats to both ecological systems and human health. Dicamba, one of the most widely used herbicides, is particularly problematic due to its high volatility and water solubility, which can lead to rapid environmental dispersal, non-target toxicity, and groundwater contamination. To mitigate these issues, we synthesized a novel cocrystal of dicamba and phenazine (DCB-PHE cocrystal) through a combination of theoretical prediction and mechanochemical screening. The DCB-PHE cocrystal was characterized using single-crystal and powder X-ray diffraction, Fourier-transform infrared spectroscopy (FT-IR), and thermal analysis. Compared to pure dicamba, the DCB-PHE cocrystal exhibited a substantial reduction in volatility by 59 % and a decrease in equilibrium solubility by up to 5.4 times across various temperatures (15 °C, 25 °C, 35 °C). Additionally, the dissolution rates were significantly lowered by over 94 %. Leaching experiments demonstrated that the DCB-PHE cocrystal reduced total leachate by 4.9 % and delayed percolation. In greenhouse trials, the DCB-PHE cocrystal caused less damage to exposed soy plants and enhanced herbicidal activity against target weeds, with fresh weight reduction of chicory and ryegrass by 32 % and 28 %, respectively, at the highest dosage. Furthermore, safety assays confirmed that the DCB-PHE cocrystal's safety profile was comparable to that of dicamba in terms of its impact on wheat, and it did not exhibit increased genotoxicity to broad beans. These findings suggest that the DCB-PHE cocrystal is a promising candidate for reducing the environmental impacts of dicamba while maintaining its herbicidal efficacy. The DCB-PHE cocrystal, prepared via supramolecular self-assembly, reduces drift, slows release, and decreases leaching rates into groundwater, contributing significantly to the development green and efficient agriculture. [Display omitted] • DCB-PHE cocrystal is prepared via mechanochemical and solution methods. • DCB-PHE cocrystal reduces the volatility of dicamba, minimizing soybean leaf damage. • DCB-PHE cocrystal significantly decreases solubility and dissolution rates at various temperatures. • DCB-PHE cocrystal lowers the leaching rate of dicamba into groundwater. • DCB-PHE cocrystal enhances herbicidal activity without increasing non-target toxicity. [ABSTRACT FROM AUTHOR]

We hypothesized that we could prepare ZnO nanoparticles (ZnO NPs) as a biomedical application treatment of zinc deficiency in human populations. In this study, we report a formulation prepared using a low-cost method for the green synthesis of ZnO NPs by utilizing the medicinal species Salvia fruticosa as natural raw material and Zn(NO 3) 2 ∙6H 2 O as a Zn source. The final product was identified and characterized by elemental analysis using X-ray energy-scattering spectroscopy (EDS), ultraviolet–visible spectroscopy (UV-VIS Spectroscopy), X-ray powder diffraction (XRD), and morphometric analysis using scanning electron microscopy (SEM). Finally, crystallization was studied using transmission electron microscopy (TEM). Afterward, ZnO NPs thus produced were utilized for foliar spraying on S. fruticosa open cultures, and Zn fortification in the foliage. Then, their effects on the biosynthesis of essential oils, and Zn bioavailability to humans were studied through different modes of consumption. ZnO NPs produced using our method were spherical while some were hexagonal, with an average size of approximately 22 nm, based on XRD results. The green synthesis method devised in this study afforded ZnO NPs from Zn(NO 3) 2 ∙6H 2 O with a 95 % yield, and consequently yielded economic benefits with respect to the current market prices. Foliage Zn fortification and the desired features were successfully achieved using ZnO NPs, and the proper mode of consumption of this medicinal plant has been recommended in this study. In conclusion, the methodology described in this study enables eco-friendly green synthesis of ZnO NPs at a low cost using S. fruticosa and puts forward a contemporary and integrated biomedical use of ZnO NPs to treat disorders resulting from or related to Zn deficiency. [ABSTRACT FROM AUTHOR]

Polyamide-imide:ZnO nanocomposites (PAI:ZnO nanocomposites) were synthesized using ultrasonic cavitation technique. Meanwhile, ZnO NPs were synthesized using co-precipitation method and modified with diacid (DA) as coupling agent for enhancement in polymer–filler interaction. PAI was formed via microwave-assisted direct polycondensation of N-trimellitylimido-1-phenylglycine (DA) with 4,4′-diaminodiphenyl ether (diamine) by adding tetra-n-butylammonium bromide and triphenylphosphite as ionic liquid and condensing agent, respectively. The resulting polymer and modified ZnO NPs were employed to make PAI:ZnO nanocomposites and subjected to various characterizations [Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), X-ray powder diffraction, and field emission scanning electron microscopy (FESEM)]. The synthesized ZnO NPs were found to be spherical in shape with monodispersed form, which is evidenced from FESEM. TGA result reveals enhancement in thermal stability of nanocomposites with increase in amount of ZnO NPs loadings. Optical properties of nanocomposites show enhancement in-between ultraviolet region with amount of loadings. Moreover, the antibacterial studies have been carried out and found to be improved with increase in amount of ZnO NPs loading. [ABSTRACT FROM AUTHOR]

To degrade phenol with the heterogeneous Fenton-like process and to compare the results, micro-scale zero-valent iron particles (mZVI) and nickel-coated iron bimetallic particles (Ni/Fe) were used. Oxygen was given to the system and converted to H2O2 and •OH radicals. The changes in the properties of mZVI and Ni/Fe particles after the reaction were determined by scanning electron microscope (SEM), X-ray energy-dispersive spectrometer (EDX), Brunauer–Emmett–Teller (BET), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) before and after the reaction. For phenol removal with an initial phenol concentration of 25 mg/L, initial pH of 3 and air flow rate of 150 L/h, 3 g/L dosage and 360 min reaction time for mZVI, 1.5 g/L dosage and 240 min for Ni/Fe reaction time were sufficient. Under these conditions, 76% and 98% phenol removal and 39% and 47% total organic carbon (TOC) removal were obtained for mZVI and Ni/Fe, while 189 and 85 mg/L H2O2 were produced, respectively. While ${\rm SO}_4^{-2}$ SO 4 − 2 and ${\rm PO}_4^{-3}$ PO 4 − 3 caused a slight increase in phenol removal efficiency in the mZVI system, these ionic species and Cl- and ${\rm NO}_3^-$ NO 3 − caused a decrease in the efficiency in the Ni/Fe system. The possible degradation pathway for phenol was suggested by high performance liquid chromatography (HPLC) analysis and hydroquinone, pyrocatechol, maleic acid, benzoquinone and acetic acid were the main intermediates. According to the cost analysis, when using mZVI to treat 1 m3 25 mg/L phenolic wastewater, the cost was $228.15, which was 1.45 times higher than the cost for Ni/Fe. [ABSTRACT FROM AUTHOR]

Semiconductors, with their exceptional properties, have diverse applications across fields such as photovoltaics, sensing, and catalysis. In the present study, nickel pyro-vanadate compounds of high purity and homogeneity, with the chemical formula A2NiV2O7 (where A = Na, Ag), were synthesized under precisely controlled stoichiometric conditions. The primary focus is to investigate the optical and electronic properties of these compounds using a combination of experimental techniques and theoretical modeling. Initially, insights into the chemical structure and morphology of the synthesized semiconductor were obtained through powder x-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). A2NiV2O7 were found to be homogeneous, crystalline in nature, and isotypic with Κ2CoV2O7, exhibiting alternating layers of NiV2O7 and Ag/Na. Moreover, absorption spectra obtained from UV–Vis diffuse reflectance spectroscopy (DRS) showed direct optical bandgaps of 1.83 eV for Na2NiV2O7 and 1.92 eV for Ag2NiV2O7, affirming their semiconductor properties. Further characterization was performed using density functional theory (DFT) and hybrid-DFT methods. These advanced techniques provide detailed understanding of the electronic structure and properties across different sodium–silver ratios. The computed electronic structures demonstrate the separation of the conduction band (CB) and valence band (VB) around the Fermi level, with bandgaps of 0.44 eV and 1.76 eV for Na2NiV2O7, and 0.56 eV and 1.60 eV for Ag2NiV2O7, as determined using the Perdew–Burke–Ernzerhof (PBE) and DFT+U methods, respectively. This comprehensive investigation offers valuable insights into the optical and electronic dynamics of nickel pyro-vanadate compounds, establishing a foundation for their potential applications in various fields, including optoelectronics, photocatalysis, and energy storage. [ABSTRACT FROM AUTHOR]

We report the synthesis of phosphorus (P)-doped reduced graphene oxide (P-rGO) using a hydrothermal method at 180°C for 7 h. Furthermore, the amorphous nature and phase purity of the hydrothermally synthesized P-rGO was studied by powder x-ray diffraction. The characteristic sheet-like surface structure of the P-rGO was confirmed by scanning electron microscopy. The presence of P in the P-rGO was authenticated by using energy-dispersive x-ray spectroscopy and photoelectron x-ray spectroscopy. The synthesized P-rGO was employed as a low-cost and Pt-free counter electrode material for the construction of dye-sensitized solar cells (DSSCs). The effect of annealing temperature on the construction of the DSSCs using P-rGO was also studied, and the highest power conversion efficiency of 6.3% and photocurrent density of 15.37 mA/cm2 were obtained at 200°C. The platinum counter electrode-based DSSCs exhibited the power conversion efficiency of 7.4%. The performance of the P-rGO counter electrode-based DSSCs was reasonable and can be further improved by developing novel device architectures. This work proposes the simple, eco-friendly, and Pt-free counter electrode for the construction of DSSCs with a decent performance. [ABSTRACT FROM AUTHOR]

Naturally Occurring Asbestos (NOA) has drawn the attention worldwide when investigation revealed an increased incidence of malignant mesothelioma in population living near NOA sites. In Basilicata region (South Italy), population living in the villages of Castelluccio Superiore and Inferiore, Lauria, Latronico, Episcopia, San Severino Lucano, and Francavilla in Sinni may be considered at high risk of asbestos exposure because these villages are either surrounded by or built on NOA-rich ophiolitic outcrops. In this work we investigated an asbestos tremolite sample coming from the ophiolitic rocks outcropping in the quarry of Iacolinei, widely used in the past to extract aggregates for various applications. A detailed mineralogical characterization has been attained by using a multi-analytical approach (EMPA, SEM-EDS, TEM-EDS, Mössbauer, µ-Raman, X-ray powder diffraction, and thermal analysis). Morphological investigation highlighted that the sample is composed of long fibers (> 5 µm) with a significant fraction (ca. 55%) having width below 0.25 µm, considered the most biologically active fibers. Moreover, the crystal chemical characterization showed that Fe occurs at the octahedral sites of the tremolite structure. It should be noted that Fe plays a primary role in the toxicity of asbestos. Based on these results, the investigated asbestos tremolite may be considered a potent mesothelial carcinogen, requiring therefore special attention for public health protection purposes. Investigations using sentinel animals to assess the diffusion of the tremolite fibers into the environment from the serpentinite rocks and soils of Iacolinei quarry are in progress. [ABSTRACT FROM AUTHOR]

Three new three-dimensional (3D) metal–organic frameworks [M2(ttdc)2(dabco)] (M = Zn(II), 1-Zn; Cu(II), 1-Cu; and Zn/Cu, 1-ZnCu) based on thieno[3,2-b]thiophene-2,5-dicarboxylate (ttdc2−) were synthesized and characterized by a combination of physicochemical methods (single crystal X-ray diffraction, powder X-ray diffraction, chemical and thermogravimetric analyses and IR spectroscopy). 1-Cu demonstrated permanent porosity (Vpore = 0.790 cm3 g−1 and SBET = 1725 m2 g−1) and significant CO2, CH4, C2H2, C2H4 and C2H6 gas uptakes under ambient conditions. The adsorption selectivities for gas mixtures, calculated by IAST, were 10.8 (10.7), 14.6 (9.4), 1.7 (1.6) and 1.5 (1.6) for the equimolar gas mixture compositions CO2/N2, C2H6/CH4, C2H6/C2H4 and C2H6/C2H2 at 1 bar and 273 K (298 K), respectively. The mixed-metal compound 1-ZnCu was prepared by a crystal-to-crystal ion exchange metathesis reaction from 1-Zn with a 52% degree of ion substitution, confirmed by energy-dispersive X-ray spectroscopy, optical microscopy and single crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

The luminescent properties of europium (Eu) doped BaAl2O4 phosphors were strongly influenced by post-annealing temperatures for blue-green persistent luminescence and latent fingerprints (LFPs). The X-ray powder diffraction patterns of the BaAl2O4: 1 mol% Eu nanophosphor, annealed between 1000 and 1300 °C, indicated a hexagonal ferroelectric phase. The X-ray photoelectron spectroscopy (XPS) revealed that the Ba atoms occupied two different sites in the BaAl2O4. The XPS and photoluminescence (PL) results revealed the presence of Eu3+ and Eu2+ states. The Eu-doped BaAl2O4 showed the characteristic red emission of Eu3+ at 251 and 464 nm excitations, while excitations at 340 and 380 nm showed yellowish-green emission. Strong evidence of energy transfer between a charge transfer band and the different energy levels of Eu2+ and Eu3+ ions was obtained. The existence of the Cr ion impurity in the aluminates was confirmed with UV-VIS diffuse reflectance and PL spectroscopy. The present results suggested that and O′′i defects have introduced electron and hole traps in the host that acted as luminescent centers for persistent luminescence. LFPs detection using BaAl2O3:Eu2+/Eu3+ phosphor showed an excellent marking agent for applications in forensic science. [ABSTRACT FROM AUTHOR]

The ability of a compound to form different crystalline structures, possessing distinct chemical and physical properties, is known as polymorphism. To identify the isolable polymorphs of a compound, extensive screening of experimental crystallization conditions is often carried out in a high-throughput fashion, where only powder X-ray diffraction (PXRD) patterns are obtainable. The room-temperature diffractograms must then be compared to low-temperature, single-crystal X-ray structures, such as from the Cambridge structural database (CSD), to identify if a particular solid form is a new or pre-existing polymorph. This comparison is problematic because the PXRD peak positions shift substantially with temperature. The variable-cell experimental powder difference (VC-xPWDF) method was recently developed to allow reliable comparison of experimental PXRD patterns to simulated diffractograms of known crystal structures. This work demonstrates the utility of VC-xPWDF to solve crystal structures from PXRD data generated during high-throughput polymorph screening for the test case of 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, also known as ROY, which is a prolific polymorph former. The method is shown to be successful for the comparison of PXRD patterns to both experimental crystal structures from the CSD and computationally generated structures obtained from a previous crystal structure prediction study. The experimental diffractogram quality was shown not to affect the results in most cases, although some errors do occur due to preferential orientation and low intensity/high baseline noise, which could potentially be reduced by additional grinding of the samples prior to making the PXRD measurements or slightly longer X-ray exposure during data collection. [ABSTRACT FROM AUTHOR]

This study is focused on the synthesis of the perovskite oxide materials, particularly Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ , using different synthetic approaches (sol-gel and co-precipitation techniques) and different complexing agents and fuels and their applications for electrochemical water splitting and fuel cells. Prepared perovskite oxide materials exhibits dual catalytic behaviour as it shows the catalytic activity toward the oxygen evolution and reduction reactions in alkaline solution. The Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ electrocatalyst exhibits remarkable efficiency and durability for the OER in basic electrolytes, with a Tafel slope of 70.38 mV/dec for Best catalyst. The best ORR activity observed for Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ synthesized using citric acid shows Tafel slope of 356.43 mV/dec. These oxide materials also show enhanced efficiency in capacitive applications. Additionally, the prepared perovskite oxide materials have been characterized by Powder X-ray diffraction, Le-Bail refinement, scanning electron microscopy, Energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy analysis, and high-resolution Transmission Electron Microscopy. Electrochemical techniques such as linear sweep voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy techniques were used to assess the catalytic performance of the prepared electrocatalysts in 0.1M KOH solution. [Display omitted] • Perovskite oxides were synthesized and characterized. • Characterization was done by SEM, TEM, XPS and PXRD. • The catalysts prepared were utilized as bifunctional electrocatalysts. • Bifunctional electrocatalysts display dual catalytic activity for both the OER and the ORR in an alkaline media. [ABSTRACT FROM AUTHOR]

The development of multi-doped oxides based on the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3–δ (LSCF) and La 1–x Sr x MnO 3+δ perovskites would help to achieve the improved electrochemical activity of air electrodes in protonic ceramic cells due to the formation of the single-phase triple-conducting material. The search for prospective medium-entropy and high-entropy oxides based on (La,Sr)(Co,Fe,Mn)O 3–δ could provide the electrode material with advanced hydration ability. In the present work, the formation and stability of new La 0.6 Sr 0.4 Co x Fe 1–x–y Mn y O 3–δ phases are estimated by thermodynamic calculations and the structure factors. Experimentally obtained La 0.6 Sr 0.4 Co x Fe 1–x–y Mn y O 3–δ powder samples are characterized by X-ray and neutron powder diffraction. The refined crystal structure parameters of the medium-entropy single-phase La 0.6 Sr 0.4 Co 0.33 Fe 0.33 Mn 0.33 O 3–δ (LSCFM333) oxide with the trigonal structure (space group R 3 ‾ c) and the cell parameters of a = 5.4642(1) Å and c = 13.284(4) Å in hexagonal axes are used to design of a supercell simulation for density functional theory (DFT) calculations. The first-principles results are proposed to evaluate the thermodynamic parameters of proton uptake to assess future applications of Mn-doped LSCF in proton-conducting ceramic cells. The calculated values of the hydration enthalpy Δ H h y d r for the LSCF and LSCFM333 derivatives are equal to 4.5 kJ mol−1 and –3.5 kJ mol−1, respectively, which are supported by the thermogravimetric analysis (TGA). The present study shows that the modeling techniques, including the thermodynamic and DFT calculations, can be successfully applied to the design of the related oxide materials for applications in solid oxide cells. [Display omitted] • Formation of La 0.6 Sr 0.4 Co x Fe 1–x–y Mn y O 3–δ phases was estimated and approved. • Crystal structure of Mn-doped LSCF was determined from neutron diffraction data. • Decrease in hydration enthalpies with Mn-doping was demonstrated by DFT and TGA. • Proton shift was found to affect the hydration enthalpy value. [ABSTRACT FROM AUTHOR]

La 2- x Pr x Ni 1- y Cu y O 4+δ (x = 0.5, 1, 1.5, y = 0.4, 0.6, 0.8) were synthesized by a citrate-nitrate method and studied as cathode materials for IT-SOFCs by Electrochemical Impedance Spectroscopy (EIS) in symmetrical cells based on the Ce 0.8 Sm 0.2 O 2-δ (SDC) and La 28- z W 4+ z O 54+1.5 z (z = 0.85, LWO) electrolytes. Phase identification and crystal structure analysis by means of X-ray powder diffraction (XRPD) shows that solubility of copper y decreases with the increase in praseodymium content x due to increasing structural distortions. Thermodynamic stability of La 2- x Pr x Ni 1- y Cu y O 4+δ at intermediate temperatures in air tends to decrease with praseodymium doping level x and increases with copper substitution for nickel y. Oxides with x = 0.5 and 0.6≤ y ≤ 0.8 are shown to be thermodynamically stable at 700 °C in air. Electrochemical performance of the La 2- x Pr x Ni 1- y Cu y O 4+δ electrodes improves with praseodymium and copper doping. The results of EIS measurements at different temperatures and oxygen partial pressures (P (O 2)) reveal that the rate-determining step of the overall electrochemical process is charge transfer, which can be a combination of surface diffusion and bulk diffusion. EIS studies in dry and wet air indicate the presence of proton conduction in the studied electrodes. The area-specific resistances (ASRs) for La 2- x Pr x Ni 1- y Cu y O 4+δ with x = 0.5, y = 0.6 and y = 0.8 in contact with SDC are comparable with those reported for Pr 2 NiO 4+δ and equal to 0.07 and 0.065 Ω cm2 at 800 °C. [Display omitted] • Thermodynamic stability of La 2-x Pr x Ni 1-y Cu y O 4+δ (LPNC) in air increases with Cu doping. • Increase in Pr and Cu content improves the electrochemical performance of LPNC. • The overall electrochemical reaction is limited by the charge transfer in electrode. • Rate-determining step can be a combination of surface diffusion and bulk diffusion. • Impedance spectroscopy studies indicate the possibility of proton conduction in LPNC. [ABSTRACT FROM AUTHOR]

The crystal structure of a novel MAX phase is determined using X-ray powder diffraction, spherical aberration corrected transmission electron microscopy, and first-principles calculations. In the new V–Sn–C system, the R 3 ‾ m space group aligns more closely with the experimental data than the P 6 3 /mmc space group. The lattice parameters of the new trigonal V 2 SnC phase are a = 0.291 nm and c = 2.08 nm. Moreover, the surface of the new phase has a tin-doped carbide face-centered cubic (FCC) structure reconstruction layer. First-principles calculations indicate that the new trigonal V 2 SnC phase is metastable compared with the hexagonal V 2 SnC phase. However, the thermal stability of the metastable trigonal V 2 SnC in air is significantly enhanced owing to the presence of the reconstruction layer. [ABSTRACT FROM AUTHOR]

AbstractA series of Co(II), Ni(II), Cu(II), Zn(II) complexes have been synthesized with a benzothiazole azo dye containing tridentate (NNO) donor ligand 4-(((6-nitrobenzo[d]thiazol-2-yl)imino)methyl)benzene-1,3-diol derived from 2-amino-6-nitrobenzothiazole and 2,4-dihydroxybenzaldehyde. The structures of the novel ligand and metal complexes were identified and confirmed via various spectroscopic techniques (FT-IR,1H NMR,13C NMR, UV-Vis, mass spectrometry), TGA-DTA, powder X-ray diffraction, and DFT calculations. The optimal structural parameters and chemical reactivity of the ligand and metal complexes have been investigated using Density Functional Theory calculations (DFT/B3LYP,6-31G** and LanL2DZ basis sets) to provide insight about their frontier molecular orbitals (FMO) and molecular electrostatic potential (MESP). In vitro DPPH radical scavenging techniques have been used to assess the antioxidant activity of the ligand and complexes, indicating good antioxidant activity. The Ni(II) complex was the most potent with the lowest IC50 values. The in vitro antibacterial activities have been explored by screening against bacteria (Bacillus subtilis) and bacteria (E. coli) exhibiting significant activity against the tested strains of bacteria with Zn(II) complex as most potent with the lowest MIC value against E. coli and B. subtilis) and highest zone of inhibition against E. coli and B. subtilis at 1000 μg/mL concentration). The antifungal activity of complexes against Aspergillus niger and Candida albicans indicate that the Co(II) complex is most active for C. albicans and Zn(II) complex for A. niger . [ABSTRACT FROM AUTHOR]

In the context of climate change, it is of utmost importance to replace the use of fossil fuels as raw material in areas of industrial interest, for example, in the production of chemical inputs. In this context, a viable option is biomass, since by subjecting it to chemical processes such as pyrolysis, it is possible to obtain platform molecules that are the basis for the generation of value-added chemical products. Acetals are molecules obtained from biomass derivatives, which have various applications in cosmetic chemistry, in the pharmaceutical industry as intermediates or final compounds, food additives, among others. Different catalysts have been used in the acetalization reaction, including MOFs, which have the advantage of being porous materials with high surface area values. The large surface area translates into a greater number of catalytically active sites available for the reaction. Among the MOFs that have been used for this purpose is MOF-808, which is characterized by having a lower number of ligands attached to its metal cluster, therefore, it has a greater exposure of the metals that make up its structure. In this context, the work carried out studied the catalytic performance of MOF-808 when its Zr(IV) metal centers are replaced by Hf(IV) and Ce(IV) atoms in the acetalization reaction of benzaldehyde with methanol. The MOFs obtained by solvothermal synthesis were characterized by powder X-ray diffraction, N2 adsorption and desorption, FT-IR spectroscopy, acid–base potentiometric titration, XPS and thermogravimetric analysis. The results of the catalysis indicate that the MOF with the best performance was MOF-808-Ce, which achieved conversions greater than 80% in a period of ten minutes. MOF-808-Ce exhibits a higher number of defects and therefore a higher availability of catalytic sites for the reaction to occur, which explains the better performance. Finally, the performance of MOF-808 in the acetalization of benzaldehyde with methanol was also supported by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are porous crystalline materials that display a wide variety of physical and chemical properties. Their single crystal structure determination is often challenging because in most cases micro- or nano-sized crystals spontaneously form upon MOF synthesis, which cannot be recrystallized. The production of larger single crystals for structure determination involves optimizing, and thus modifying, the conditions of synthesis, in which success cannot be guaranteed. Failure to produce crystals suitable for single-crystal X-ray diffraction leaves the 3D structure of the MOF compound unknown, and scientists must resort to more challenging structure solution methods based on X-ray powder or electron diffraction data. These laborious tasks can be avoided by using serial crystallography techniques which merge data collected on many micro-crystals. Here, we report the application of three synchrotron serial crystallography methods. We call these "mesh", "grid" and "mesh&collect" scans. "Still" images (no rotation) are collected in the mesh scan approach, whereas small rotational wedges are collected in the grid scan method. The third protocol, mesh&collect, combines the acquisition of still images and rotational wedges. Using these means, we determine the ab initio structure of benchmark MOFs, MIL-100(Fe) and ZIF-8, that differ largely in unit cell size. These methods are expected to be widely applicable and facilitate structure determination of many MOF microcrystalline systems. [ABSTRACT FROM AUTHOR]

The binary boron-rich compounds α-Ir2B3−x and β-Ir2B3−x, formerly denoted as α- and β-Ir4B5, were synthesized via both arc melting followed by annealing at 800 °C (900 °C) and high-temperature thermal treatment of mixtures of the elements. X-ray structure analysis of α-Ir2B3−x was performed on a single crystal (space group C2/m, a = 10.5515(11) Å, b = 2.8842(3) Å, c = 6.0965(7) Å, β = 91.121(9)°). The orthorhombic structure of β-Ir2B3−x was confirmed by X-ray powder diffraction (space group Pnma; a = 10.7519(3) Å, b = 2.83193(7) Å, c = 6.0293(1) Å). The α-Ir2B3−x structure exhibits ordered arrangements of iridium atoms. The structure is composed of corrugated layers of boron hexagons (interlinked via external B–B bonds) alternating with two corrugated layers of iridium along the c-direction; an additional boron atom (Oc. 0.46(7)) is located between iridium layers in Ir6 trigonal prisms. The boron partial structure in β-Ir2B3−x is composed of ribbons made up of slightly corrugated quadrilateral units running along the b-direction in the channels formed by 8 iridium atoms each. DFT calculations revealed a number of bands crossing the Fermi level, predicting metallic behaviors of the two compounds. β-Ir2B3−x is characterized by a pseudogap around the Fermi level and a smaller eDOS of 0.6405 states per eV per f.u. at the Fermi level, as compared to the α-Ir2B3−x value of 1.405 states per eV per f.u. The calculated electron localization functions revealed strong covalent bonds between boron atoms in the core part of the B6 hexagons, metallic B–B bonds within the quadrilateral boron partial structure and mixed covalent and metallic interactions between iridium and boron atoms. Structural relationships of α-Ir2B3−x and β-Ir2B3−x with ReB2-type structures as well as the common structural features with layered binary borides with CrB-type related structures have been discussed. [ABSTRACT FROM AUTHOR]

We prepared an organically templated magnet, (enH2)0.5VPO4OH (enH2 = diprotonated ethylenediamine), hydrothermally and characterized its crystal structure by powder X-ray diffraction and Fourier-transform infrared spectroscopy, and its physical properties by magnetization, specific heat and nuclear magnetic resonance measurements and density functional theory calculations. (enH2)0.5VPO4OH consists of uniform chains of V3+ (d2, S = 1) ions and exhibits Haldane magnetism with spin gap Δ = 59.3 K from the magnetic susceptibility χ(T) at μ0H = 0.1 T, which is reduced to 48.4 K at μ0H = 9 T according to the 31P shift. The NMR data evidence the formation of a spin-glass state of unpaired S = 1/2 spins at TS–G ≈ 3 K and indicate that the Haldane S = 1 spin chain segments are much longer in the organically templated magnet (enH2)0.5VPO4OH than in the ammonium counterpart NH4VPO4OH. The single-ion anisotropy D and the interchain exchange J′ in (enH2)0.5VPO4OH and NH4VPO4OH were estimated in density functional calculations to find them very weak compared to the intrachain exchange J. [ABSTRACT FROM AUTHOR]

AbstractTo analyze ligand characteristics and use, a benzamide-derived ligand(benzoyl glycine) was synthesized and characterized before complexing it with zinc(II) ions. The ligand was formed from benzamide and glycine, obtained upon purification and precipitation. FTIR and 1H NMR were used to characterize the ligand. Furthermore, thermogravimetric analysis (TGA) was used to study the thermal behavior of the ligand and its Zn(II) complex, revealing important thermodynamic characteristics. The zinc complex was subjected to X-ray powder diffraction experiments, which yielded structural insights. Density Functional Theory (DFT) calculations were used in molecular modeling to clarify structure and characteristics of the molecules. Moreover, anti-microbial tests were used to assess biological activity against E. Coli and A. Niger. This thorough investigation lays the foundation for future research in this area by offering insightful information about the synthesis, characterization, and possible uses of the ligand and its Zn(II) metal complexes. [ABSTRACT FROM AUTHOR]

A series of B, N and O-co-doped samples, CPFP-3/1, CPFP-2/1 and CPFP-1/1, with spherical morphological features have been synthesized by carbonization of a polymer obtained by co-condensation of 1,4-phenylenediamine/formaldehyde/phloroglucinol (PFP) in the presence of tetraethyl orthosilicate. Boric acid (H3BO3) has been used here as an external doping agent to introduce B into the frameworks. To distinguish the properties of the B-doped samples from their undoped counterpart, another sample has been synthesized without the addition of H3BO3 (CPFP-1/0). The materials have been thoroughly characterized by powder X-ray diffraction, nitrogen adsorption/desorption studies, scanning electron microscopy and X-ray photoelectron spectroscopy. All the samples possess a high specific surface area and are predominantly microporous in nature. The electrochemical behaviour of the samples has been studied thoroughly using cyclic voltammetry, galvanostatic charge/discharge studies and impedance spectroscopy in 1 M H2SO4 electrolyte. The specific capacitances of all the samples are high with the values improving as the number of B-atoms (total heteroatoms) increases from CPFP-1/0 to CPFP-3/1, CPFP-2/1 and CPFP-1/1 introducing pseudocapacitive behaviour. CPFP-1/1 with 1 : 1 doping of the polymer with H3BO3 is the best performer showing a specific capacitance of 977 F g−1 at 1 A g−1 and 700 F g−1 at 30 A g−1 with a high discharge time. It has a notable specific energy density of 110 W h kg−1 at a specific power of 449 W kg−1 at 1 A g−1, performance-wise bridging the gap between supercapacitors and batteries. Additionally, beyond the potential window of supercapacitance (0–0.9 V), at higher voltage the material shows water splitting activity through the oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

With the increasing research on giant dielectric materials, there is growing interest in the development of switching materials with giant dielectric properties. In this study, a novel organic–inorganic hybrid material (Et3NC2H4Br)FeCl4 was synthesized. It was characterized through differential scanning calorimetry (DSC) and in situ temperature-dependent powder X-ray diffraction (PXRD), which determined its phase transition temperature (TC) to be 362 K. Temperature-dependent dielectric measurements revealed that the material exhibited switchable dielectric properties, with the real part of the dielectric constant exceeding 106 at 500 Hz and a dielectric switching ratio surpassing 103. The ratio refers to the ratio between the high dielectric state and the low dielectric state of a step-like dielectric anomaly. Single-crystal X-ray diffraction (SCXRD) analysis confirmed that the material crystallized in the P21/c space group with a zero-dimensional structure. The optical bandgap, determined through UV-visible spectroscopy, was calculated to be 2.62 eV. Additionally, analysis using Hirshfeld surfaces and 2D fingerprint plots revealed that the predominant intermolecular interactions are H⋯Cl and H⋯H interactions. This study is anticipated to provide insights and hope for the design and application of high-temperature giant dielectric switching materials. [ABSTRACT FROM AUTHOR]

In this study, we report the efficient removal of organic dyes from aqueous solutions using a newly synthesized pyrene-appended Zn(II)-based metal–organic framework (MOF), ZnSiF6Pyrene MOF, with the chemical formula C52H32F6N4SiZn·4(CHCl3). The MOF was synthesized through a facile method at room temperature using a dipyridylpyrene ligand and ZnSiF6 metal source, resulting in a highly crystalline structure with pyrene functional groups forming the framework. The synthesized MOF was characterized using various analytical techniques, including Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD) analysis, and scanning electron microscopy (SEM). Thermal stability was assessed using thermogravimetric analysis (TGA), while the surface area of the MOF was determined using a Brunauer–Emmett–Teller (BET) surface analyzer. Furthermore, the single-crystal X-ray diffraction (SCXRD) structure was studied to authenticate its solid-state structure. The as-synthesized MOF exhibited remarkable adsorption capacity towards various organic dyes, including Congo red (CR), rhodamine B (RhB), and methyl violet (MV), due to its ample surface area and strong π–π interactions between the pyrene moieties and dye molecules, as demonstrated by experimental and in silico docking studies. The photocatalytic degradation of MV dye was also investigated. Detailed trapping tests indicate that hydroxyl (˙OH) and superoxide (O2˙−) radicals are likely the primary active species responsible for the photodegradation of the dye under study. Furthermore, the photocatalytic property of the MOF was investigated under visible light irradiation, demonstrating excellent ability to generate singlet oxygen. This study highlights the potential of pyrene-appended Zn(II)-based MOFs as promising materials for environmental remediation applications. [ABSTRACT FROM AUTHOR]

Nucleation control and isolation of polymorphic forms of the essential pharmaceutical medicine aspirin (ASP) was examined by a supersaturation-dependent swift cooling crystallization process using acetonitrile as solvent. In the present investigation, a saturated solution was prepared at 323 K and swiftly cooled down to various temperatures below the equilibrium temperature in steps of 1 K by conducting a series of 49 systematic cooling experiments which gave a very clear nucleation matrix, indicating the preferred nucleation region of all the three polymorphic forms of aspirin under different supersaturation conditions in the range 0.20 < σ < 1.65. Moreover, an observed solution-mediated polymorphic phase transformation (SMPT) under specific supersaturation conditions (σ = 0.97) indicates that the dissolution of characteristic faces {1¯ 0 2} and {1¯ 1 1} occurs in the grown metastable form-II, and the characteristic face {0 0 2¯} of form-I simultaneously nucleates and grows over form-II in the −c and +c crystallographic directions on the surface of form-II. This discovery may provide a better understanding of the intergrowth phenomenon of aspirin polymorphs. The occurrence of this peculiar phenomenon was further ensured by attachment energy calculations, morphology assessment, and relative area analyses. Also, the nucleation kinetics of the grown ASP polymorphs were evaluated using the experimentally obtained induction time and calculated supersaturation values, by the classical nucleation theory (CNT) approach, and these results are well matched with the obtained experimental results. The structural and phase stability of the grown polymorphs were ascertained by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) analyses. [ABSTRACT FROM AUTHOR]

AbstractTiO2 nanoparticles were synthesized using the reduction precipitation method, verified by powder x-ray diffraction (PXRD) with an average crystallite size of 62 nm and an average particle size of 135 nm from SEM images. Rheological studies of brake fluid with nanoparticle additives revealed that while the fluid generally maintains consistent behavior, a 2 wt.% concentration showed non-Newtonian behavior at 120 °C. Viscosity increased slightly with nanoparticle addition and decreased with rising temperature, with the 0.5 wt.% sample demonstrating the most notable increase of 18.18% at 120 °C. At 30 °C, the 1 wt.% sample exhibited a 4.06% increase. The observed viscosity changes are attributed to higher internal shear stress and the need to manage dispersion solid elements. The Herschel-Bulkley model was effective in predicting sample behavior, and all samples conformed to Reynolds’ equation μ0=be−aT. This research indicates that TiO2 nanoparticles can be effectively used as brake fluid additives, offering potential benefits for high-temperature applications in vehicles. Further optimization using mathematical models such as response surface methodology (RSM) is suggested for improved performance. [ABSTRACT FROM AUTHOR]

In this study, we report the biosynthesis of Nickel ferrite using Ocimum sanctum leaf extract (OSLE@NiFe2O4). The single-phase cubic spinel structure of the synthesized nickel ferrite was confirmed by powder X-ray diffraction (PXRD) analysis. Structural characteristics were further examined using FTIR analysis. Optical and morphological properties were investigated through UV–DRS and FESEM studies. The magnetic hysteresis loop (M-H loop) confirmed the superparamagnetic nature of OSLE@NiFe2O4 nanoparticles. The photocatalytic degradation of Congo Red (CR) dye by the synthesized OSLE@NiFe2O4 nanoparticles was explored, revealing a pseudo-first-order kinetic behavior with a degradation efficiency of 99.9% and a rate constant of 0.06min−1. These findings demonstrate the superior photocatalytic activity of the biosynthesized nickel ferrite nanoparticles, highlighting their significant potential for efficient dye removal. [ABSTRACT FROM AUTHOR]

Thermodynamic properties of CdSb binary compound were determined using an electromotive force measurement (e.m.f.) method with a liquid electrolyte in the ~300-450K temperatures interval. Equilibrium alloys from the CdSb+Sb phase region of the Cd-Sb system was analyzed by means of the e.m.f. measurements. Phase compositions of all samples were controlled using powder X-rays diffraction method. The partial molar functions of cadmium in alloys, the standard thermodynamic functions of formation, as well as the standard entropy of the CdSb compound were calculated. A comparative analysis of obtained results with literature data was performed. [ABSTRACT FROM AUTHOR]

Context: Ammonium Tutton salts have been widely studied in recent years due to their thermostructural properties, which make them promising compounds for application in thermochemical energy storage devices. In this work, a detailed experimental study of the Tutton salt with the formula (NH4)2Zn(SO4)2(H2O)6 is carried out. Its structural, vibrational, and thermal properties are analyzed and discussed. Powder X-ray diffraction (PXRD) studies confirm that the compound crystallizes in a structure of a Tutton salt, with monoclinic symmetry and P21/a space group. The Hirshfeld surface analysis results indicate that the main contacts stabilizing the material crystal lattice are H···O/O···H, H···H, and O···O. In addition, a typical behavior of an insulating material is confirmed based on the electronic bandgap calculated from the band structure and experimental absorption coefficient. The Raman and infrared spectra calculated using DFT are in a good agreement with the respective experimental spectroscopic results. Thermal analysis in the range from 300 to 773 K reveals one exothermic and several endothermic events that are investigated using PXRD measurements as a function of temperature. With increasing temperature, two new structural phases are identified, one of which is resolved using the Le Bail method. Our findings suggest that the salt (NH4)2Zn(SO4)2(H2O)6 is a promising thermochemical material suitable for the development of heat storage systems, due to its low dehydration temperature (≈ 330 K), high enthalpy of dehydration (122.43 kJ/mol of H2O), and hydration after 24 h. Methods: Computational studies using Hirshfeld surfaces and void analysis are conducted to identify and quantify the intermolecular contacts occurring in the crystal structure. Furthermore, geometry optimization calculations are performed based on density functional theory (DFT) using the PBE functional and norm-conserving pseudopotentials implemented in the Cambridge Serial Total Energy Package (CASTEP). The primitive unit cell optimization was conducted using the Broyden–Fletcher–Goldfarb–Shanno (BFGS) algorithm. The electronic properties of band structure and density of states, and vibrational modes of the optimized crystal lattice are calculated and analyzed. [ABSTRACT FROM AUTHOR]

This study is an attempt to compare the hyperthermia and antimicrobial activity of three members of the family of spinel ferrite magnetic nanoparticles (XFe2O4, where X = Mg, Cu, and CO) MNPs. Spinell ferrite of MgFe2O4, CuFe2O4, and CoFe2O4 were prepared via sol–gel method. Structural and morphological shapes were investigated by different techniques X-ray diffraction X-ray powder diffractometer (XRD), Fourier transformed infrared spectroscopy (FTIR), and (Transmission electron microscope) TEM. Magnetic properties were examined by vibrating sample magnetometer (VSM). The in vitro test was conducted on cervical Hela cells using an MTT assay. Finally, the antimicrobial activity was tested on Staphylococcus aureus, Bacillus subtlus, and Escherichia coli using a clearing inhibition zone. XRD results confirmed the crystalline nature of MgFe2O4, CuFe2O4, and CoFe2O4. VSM results showed a high maximum saturation (Ms = 44.87 emu/g) of CuFe2O4 which is greater than that of CoFe2O4 and MgFe2O4 (18.221 and 18.669) emu/g, respectively. MTT assay revealed that high cell death was detected on Hela cells of CuFe2O4 compared to that of MgFe2O4 and CoFe2O4. The anti-microbial study showed that the prepared spinel magnetic nanoparticles possessed antimicrobial activity due to the release of Mg, Cu, Co, and Fe ions. Results showed that the CuFe2O4 could be a good spinel ferrite for medical application with antimicrobial activity and generate heat (hyperthermia, anti-cancer material). [ABSTRACT FROM AUTHOR]

Five new coordination polymers, namely [Ln(L)(NO3)2] n (Ln = La (1), Pr (2) and Sm (3)), [Eu(L)(NO3)2·1.5H2O] n (4) and [Tb(L)(OAc)2(H2O)·3H2O] n (5) (HOAc = CH3COOH), were synthesised by reaction of lanthanide nitrates with 1,3-bis(4-carboxybenzyl)benzimidazolium chloride (H2L+Cl−) under solvothermal conditions. All the coordination polymers were characterised by powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, elemental analysis and single crystal X-ray diffraction. Complexes 1 – 5 exhibit two different 2-D structures due to the variation in reaction temperature. Complexes 1 – 4 are isostructural and crystallised in the monoclinic system, C 2/ c space group, showing a two-dimensional layer with Ln chains linked by L− ligands. Complex 5 crystallised in the P 21/ n space group, featuring a 2-D layer different from 1 – 4 with Tb dimers linked by L− ligands through carboxylates. Further, the luminescence properties of complexes 3 – 5 were investigated. In addition, the fluorescence lifetime and quantum efficiency of complex 4 were measured. Five two-dimensional complexes were obtained and the structures of 1 – 4 differ from that of 5 owing to the distinct coordination modes of the ligand H2L+Cl− at specific reaction temperatures. Further, the luminescence properties of complexes 3 – 5 were investigated. Additionally, the fluorescence lifetime of complex 4 was tested. (Image credit: Li-Xin You.) [ABSTRACT FROM AUTHOR]

In this paper, a semi-rigid dipyridyl-diamide ligand was selected as the organic linker to assemble with CoCl2, and a new cobalt complex [Co(EDPB) Cl2] (EDPB = (E)-4,4′-(ethene-1,2-diyl) bis(N-(pyridin-3-yl) benzamide)) was prepared under the solvothermal conditions. The structure and properties of the complex were tested by single crystal X-ray diffraction, powder X-ray diffraction, infrared spectra, thermogravimetric analysis, and solid-state UV-Vis diffuse reflectance spectra. It is found that the Co(II) atoms in the complex are tetracoordinated, which connect with EDPB ligands to form a 1D chain structure. The complex exhibits excellent absorption for visible light and highly heterogeneous catalytic activity for Cr(VI) reduction reaction with 97. 9% of reduction rate in 60 min. The complex's ability to be recycled for photocatalytic Cr(VI) reduction reaction was examined. Remarkably, it can be reused at least five times without any degradation in activity, showing its excellent cycling stability. [ABSTRACT FROM AUTHOR]

The synthesis of a novel complex [Ni3 (L3 -)2 (1,4-bib)4 (H2 O)2]·5H2 O (1) with three-dimensional framework structure was achieved through a hydrothermal reaction, employing 5-((4-carboxylphenoxy)-methyl) isophthalic acid (H3 L) as the main oxygen-containing ligand, complemented by the N-donor ligand 1,4-bis(1H-imidazol-1-yl)benzene (1,4-bib), and Ni(II) ions. The structure of complex 1 was characterized by single crystal X-ray diffraction, powder X-ray diffraction, and elemental analysis. Complex 1 is crystallized in the triclinic crystal system of P-1 space group, and its crystallographic parameters are a =1. 260 5(7) nm, b = 1. 349 1(7) nm, c = 1. 364 8(7) nm, α = 111. 913(8)°, β = 117. 251(7)°, γ =90. 732(8)°, V =1. 866 2(18) nm3, Z =1, Mr =1 769. 66, F(000) =916, μ = 0. 84 mm-1, Dc = 1. 575 mg·m-3, S =1. 06, R1 =0. 056, wR2 =0. 159. The joint contribution of semi-rigid tricarboxylic acid ligand L3 -, rigid 1,4-bib and also with Ni(II) ion to form a predictable high-dimensional structure. Complex 1 is a three-dimensional network constructed through the coordination of N and O atoms with Ni ion and the structural extension of the ligand. In addition, the magnetic properties of Ni(II) compound containing single d electron center were studied: the carboxyl group in mononuclear complex 1 only binds to one cation, resulting in magnetism in the solid being determined by the behavior of single metal ions. Variable temperature magnetic susceptibility of　χmT in complex 1 can be described by zero field splitting. [ABSTRACT FROM AUTHOR]