X-ray Diffraction Spectroscopy Research Articles

Photocatalytic degradation of methylene blue dye under solar light irradiation by zinc oxide nanoparticles using aqueous extract of Cleome gynandra

A simple green synthetic technique is proposed for the synthesis of zinc oxide nanoparticles (ZnONPs) using the plant extract Cleome gynandra as a bio-template. The morphological, functional and structural characterization of synthesized ZnONPs was investigated using several techniques, such as energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-visible spectroscopy. The synthesized ZnONPs have a wurtzite hexagonal nanostructure with an average size of 15.20 nm. Furthermore, the photocatalytic degradation of methylene blue (MB) in an aqueous solution was carried out using the synthesized ZnONPs. The photocatalytic activity of ZnONPs was investigated by adjusting physicochemical variables as reaction time, medium pH, precursor concentration, and photocatalyst dosage. All results indicate that ZnONPs produced by the green approach exhibits significant photocatalytic activity against dye molecules.

Synthesis, characterisation and voltammetric study of dimethylammonium lead iodide perovskite

In the last decade, the most investigated perovskite materials are the hybrid organic-inorganic perovskites (HOIPs) due to their optoelectronic properties and possible application in the production of photovoltaics. This interest has led to an ongoing search for new HOIP variants, alongside thorough investigations of the properties of existing HOIPs. That is why our research in the field of organic-inorganic perovskites is aimed at the synthesis, characterization, and investigation of the electrochemical properties of dimethylammonium lead iodide (DMAPbI3) using voltammetric studies. A modified synthesis of DMAPbI3, differing slightly from the one described in the literature, was performed by combining stoichiometric amounts of lead iodide (PbI2) and dimethylammonium iodide (DMAI) dissolved in acetonitrile. After conducting controlled evaporation, a yellow crystalline powder of DMAPbI3 was obtained. The identity and purity of the obtained compound were confirmed by powder X-ray diffraction (PXRD), infrared (IR) and Raman spectroscopy, and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). Investigations on the electrochemical properties of DMAPbI3 by cyclic voltammetry were performed with dichloromethane (DCM) and tetrabutylammonium chloride (TBAC) as the electrolyte. A paraffin-impregnated graphite electrode (PIGE) was used as a working electrode, on which the perovskite microparticles were immobilized. The electrochemical activity of DMAPbI3 is recognized through an intense, broad, and irreversible anodic peak attributed to the oxidation of the constituents to different possible products and the decomposition of the perovskite structure.

Comprehensive Study of Zr-Doped Ni-Rich Cathode Materials Upon Lithiation and Co-Precipitation Synthesis Steps.

Ni-rich layered oxides LiNi1-x-yMnxCoyO2 (NMC811, x = 0.1 and y = 0.1) are considered promising cathode materials in lithium-ion batteries (LiBs) due to their high energy density. However, those suffer a severe capacity loss upon cycling at high delithiated states. The loss of performance over time can be retarded by Zr doping. Herein, a small amount of Zr is added to NMC811 material via two alternative pathways: during the formation of the transition metal (TM) hydroxide precursor at the co-precipitation step (0.1%-Zr-cp) and during the lithiation at the solid-state synthesis step (0.1%-Zr-ss). In this work, the crystallographic Zr uptake in both 0.1%-Zr-ss and 0.1%-Zr-cp is determined and quantified through synchrotron X-ray diffraction and X-ray absorption spectroscopy. We prove that the inclusion of Zr in the TM site for 0.1%-Zr-cp leads to an improvement of both specific capacity (156 vs 149 mAh/g) and capacity retention (85 vs 82%) upon 100 cycles compared to 0.1%-Zr-ss where the Zr does not diffuse into the active material and forms only an extra phase separated from the NMC811 particles.

Determination of Trace Cd(II) in Water and Cosmetics based on Au/GO/CuO Nanocomposite Functionalized Electrochemical Sensor

Abstract Cadmium (Cd(II)) is highly toxic to environmental, and while many approaches have been developed to measure cumulative Cd(II) concentration over time, online monitoring of spatiotemporal changes remains challenging. To address this, an electrochemical sensor for determination of ultra-trace Cd(II) was developed, based on gold/graphene oxide/copper oxide (Au/GO/CuO) nanomaterials modifying glassy carbon electrode. CuO nanoparticles were prepared by a green synthesis method using plant extract, and the Au nanoparticles were deposited on the GO/CuO nanosubstrates by an in-situ electrochemical method. The prepared nanocomposites were characterized by field-emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The CuO nanoparticles are layered flower-like with an average particle size of 200-500 nm. Au/GO/CuO nanocomposites with high specific surface area and excellent electronic transmission capability enhanced the electrochemical signal of the sensor. Owing to the synergistic effect of Au/GO/CuO, the sensor exhibited good performance to Cd(II) in the ultra-wide range of 5×10-11 - 5×10-7 M with a detection limit of 2×10-11 M. The sensor was successfully quantified for determining Cd(II) with desirable recovery, displaying outstanding long-term stability, high sensitivity, and reproducibility. After validating its accuracy, this sensor was successfully used for detection of Cd (II) in water and cosmetic samples.

Oxygen vacancies enhanced photo-fenton-like catalytic degradation of rhodamine B by electrochemical synthesized α-Fe2O3 nanoparticles

Hematite is widely used as a catalyst in a photo-Fenton-like process for the oxidation of dyes. We report on the electrochemical synthesis of α-Fe2O3 nanoparticles. The structure, morphology, chemical composition, and surface chemical state of the catalyst, as well as its optical and magnetic properties, were thoroughly characterized by scanning electron microscopy, X-ray diffraction spectroscopy (XRD), shift combination scattering spectroscopy, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). It was found that the crystal size was 63.9 nm. It was shown that the presence of Fe2+ on the surface was due to oxygen vacancies rather than impurity phases. The optical bandgap was determined to be 1.87 eV. Nanoparticles exhibit weak ferromagnetic behavior with a magnetization of 1.09 emu/g at maximum applied magnetic field 1 kOe. The catalytic activity in the photo-Fenton-like process for the degradation of Rhodamine B (RhB) dye was investigated, and the effect of working parameters, including H2O2 concentration, catalyst concentration, and RhB concentration, on the degradation efficiency was studied. The maximum degradation rate was 99.15 % in 12 min under optimal conditions. The catalyst showed long-term stability over 5 repeated cycles.

Disentangling the effects of structure and lone-pair electrons in the lattice dynamics of halide perovskites

Halide perovskites show great optoelectronic performance, but their favorable properties are paired with unusually strong anharmonicity. It was proposed that this combination derives from the ns2 electron configuration of octahedral cations and associated pseudo-Jahn–Teller effect. We show that such cations are not a prerequisite for the strong anharmonicity and low-energy lattice dynamics encountered in these materials. We combine X-ray diffraction, infrared and Raman spectroscopies, and molecular dynamics to contrast the lattice dynamics of CsSrBr3 with those of CsPbBr3, two compounds that are structurally similar but with the former lacking ns2 cations with the propensity to form electron lone pairs. We exploit low-frequency diffusive Raman scattering, nominally symmetry-forbidden in the cubic phase, as a fingerprint of anharmonicity and reveal that low-frequency tilting occurs irrespective of octahedral cation electron configuration. This highlights the role of structure in perovskite lattice dynamics, providing design rules for the emerging class of soft perovskite semiconductors.

Effect of sandblasting and acid surface pretreatment on the specific capacitance of CuO nanostructures grown by hot water treatment for supercapacitor electrode applications.

Crystalline copper oxide (CuO) nanostructures with micro, nano, and micro-nano surface roughness were grown on Cu sheet substrates by a facile, scalable, low-cost, and low-temperature hot water treatment (HWT) method that simply involved immersing Cu sheet in DI water at 75 °C for 24 hours without any chemical additives. Various morphological features and sizes of CuO nanostructures were tuned by using different surface pretreatment techniques including acid treatment, sandblasting, or a combination of those two. The surface morphology of the prepared samples was analyzed by scanning electron microscopy (SEM). The crystal structure of the CuO nanostructures was investigated by X-ray diffraction (XRD) and Raman spectroscopy. To study the pseudocapacitive behavior, their potential supercapacitor performance, and equivalent series resistance, electrochemical analysis was done by cyclic voltammetry (CV) and electrochemical impedance spectroscopy for all the CuO/Cu samples in 1 M of Na2SO4 electrolyte. Among all, the best supercapacitive performance was achieved for CuO/Cu samples pretreated with Sandblasting followed by Acid treatment resulting in a specific capacitance of about 104 F/g. The electrode with the Sandblasted + Acid pretreated sample showed a maximum of ~ 69% capacitive retention after 2000 consecutive cycles. Our results indicate that CuO nanostructures on Cu substrates prepared with different surface pretreatment conditions and grown by HWT can be promising electrodes for supercapacitor device applications.

The Influence of PVP Polymer Topology on the Liquid Crystalline Order of Itraconazole in Binary Systems.

This study presents a novel approach by utilizing poly(vinylpyrrolidone)s (PVPs) with various topologies as potential matrices for the liquid crystalline (LC) active pharmaceutical ingredient itraconazole (ITZ). We examined amorphous solid dispersions (ASDs) composed of ITZ and (i) self-synthesized linear PVP, (ii) self-synthesized star-shaped PVP, and (iii) commercial linear PVP K30. Differential scanning calorimetry, X-ray diffraction, and broad-band dielectric spectroscopy were employed to get a comprehensive insight into the thermal and structural properties, as well as global and local molecular dynamics of ITZ-PVP systems. The primary objective was to assess the influence of PVPs' topology and the composition of ASD on the LC ordering, changes in the temperature of transitions between mesophases, the rate of their restoration, and finally the solubility of ITZ in the prepared ASDs. Our research clearly showed that regardless of the PVP type, both LC transitions, from smectic (Sm) to nematic (N) and from N to isotropic (I) phases, are effectively suppressed. Moreover, a significant difference in the miscibility of different PVPs with the investigated API was found. This phenomenon also affected the solubility of API, which was the greatest, up to 100 μg/mL in the case of starPVP 85:15 w/w mixture in comparison to neat crystalline API (5 μg/mL). Obtained data emphasize the crucial role of the polymer's topology in designing new pharmaceutical formulations.

Colossal Ferroelectric Photovoltaic Effect in Inequivalent Double-Perovskite Bi2FeMnO6 Thin Films.

Double perovskite films have been extensively studied for ferroelectric order, ferromagnetic order, and photovoltaic effects. The customized ion combinations and ordered ionic arrangements provide unique opportunities for bandgap engineering. Here, a synergistic strategy to induce chemical strain and charge compensation through inequivalent element substitution is proposed. A-site substitution of the barium ion is used to modify the chemical valence and defect density of the two B-site elements in Bi2FeMnO6 double perovskite epitaxial thin films. We dramatically increased the ferroelectric photovoltaic effect to ∼135.67 μA/cm2 from 30.62 μA/cm2, which is the highest in ferroelectric thin films with a thickness of less than 100 nm under white-light LED irradiation. More importantly, the ferroelectric polarization can effectively improve the photovoltaic efficiency of more than 5 times. High-resolution HAADF-STEM, synchrotron-based X-ray diffraction and absorption spectroscopy, and DFT calculations collectively demonstrate that inequivalent ion plays a dual role of chemical strain (+1.92 and -1.04 GPa) and charge balance, thereby introducing lattice distortion effects. The reduction of the oxygen vacancy density and the competing Jahn-Teller distortion of the oxygen octahedron are the main phenomena of the change in electron-orbital hybridization, which also leads to enhanced ferroelectric polarization values and optical absorption. The inequivalent strategy can be extended to other double perovskite systems and applied to other functional materials, such as photocatalysis for efficient defect control.

Unveiling the pressure-induced scheelite to M′-fergusonite phase transition in NaCe(MoO4)2

Sodium-cerium molybdate, NaCe(MoO4)2, belongs to the family of double alkaline rare-earth molybdate, and it holds significant importance across various technological domains, such as environmental remediation and energy conversion. Despite its importance, the behavior of NaCe(MoO4)2 under high-pressure conditions remains unexplored. This study uses synchrotron x-ray diffraction and Raman spectroscopy to investigate NaCe(MoO4)2in situ under high-pressure conditions. We observed a pressure-induced phase transition from the scheelite to the M′-fergusonite structure type on a double molybdate at approximately 10 GPa. These findings contribute to a deeper understanding of the structural stability of NaCe(MoO4)2 and shed light on the broader field of high-pressure studies of double molybdates.

Characterization of GaAs and GaAs/Cr/GaAs interfacial layers fabricated via magnetron sputtering on silicon (100)

The obtaining and study of semiconductor materials have been topics of interest for decades. However, alternatives that allow greater versatility at the time of their application have yet to be explored, such as the inclusion of some transition metals. In this work, we report the obtaining of GaAs and GaAs/Cr/GaAs layers, which were prepared by r.f. magnetron sputtering on a Si (100) substrate by varying the deposition time of the intermediate Cr layer for t = 5 min and 10 min, respectively. Scanning electron microscopy in cross-section was carried out to determine the growth mode of the GaAs and GaAs/Cr/GaAs films. The percentage of the elements in the GaAs/Cr/GaAs thin films was determined through energy dispersive spectroscopy (EDS) in cross-sections along the entire layer thickness. X-ray diffraction and micro-Raman spectroscopy at room temperature were measured to analyze the formation of CrAs and GaCr binary phases by diffusion across interlayers. Finally, we conclude on the possible use of this technique to obtain semiconductor alloys with Cr inclusion.

High-Pressure Polymorphism in Silver Ferrite Delafossite, AgFeO2.

The delafossites are a class of layered metal oxides that are notable for being able to exhibit optical transparency alongside an in-plane electrical conductivity, making them promising platforms for the development of transparent conductive oxides. Pressure-induced polymorphism offers a direct method for altering the electrical and optical properties in this class, and although the copper delafossites have been studied extensively under pressure, the silver delafossites remain only partially studied. We report two new high-pressure polymorphs of silver ferrite delafossite, AgFeO2, that are stabilized above ∼6 and ∼14 GPa. In situ X-ray diffraction and vibrational spectroscopy measurements are used to examine the structural changes across the two phase transitions. The high-pressure structure between 6 and 14 GPa is assigned as a monoclinic C2/c structure that is analogous to the high-pressure phase reported for AgGaO2. Nuclear resonant forward scattering reveals no change in the spin state or valence state at the Fe3+ site up to 15.3(5) GPa.

Characterization and antibacterial studies of Sn doped CuO nanocomposite using centratherum punctatum leaf extract

In order to synthesize CuO, SnO2, and Sn doped CuO nanocomposites, accessible and non-toxic materials, specifically leaf extract from Centratherum punctatum, were used in this work to apply the concepts and practices of green chemistry. These methods are both economical and environmentally friendly. A comprehensive range of characterisation techniques, including as FTIR, X-ray diffraction, and UV-vis spectroscopy, were also used to confirm the structures of all the produced nanomaterials. Instead, FESEM and EDAX were used to analyze the morphologies and elemental composition of recently produced nanomaterials. A decline in the optical band gap values was indicated by the red shift observed in the UV-vis study following tin doping. A sample's presence of different functional groups is confirmed by FT-IR analysis. For CuO NPs, SnO2, and Sn doped CuO NCs, the XRD results yielded crystallite sizes of 6 nm, 21 nm, and 29 nm, respectively, for the produced particles. The ferromagnetic, diamagnetic, and super paramagnetic characteristics of the produced samples at room temperature were validated by vibrating sample magnetometer experiments. Cyclic voltammetry is used to examine the nanoparticles' electrochemical analysis. Using Sn doped CuO nanocomposite material, it shows a high specific capacitance value of about ~187 Fg-1 at a current density of 10 mV/s. It was found from the electrochemical studies that the produced nanomaterials are suitable for capacitive behaviour. After all, the presence of inhibition zones surrounding each well led us to the conclusion that the nanoparticles exhibited antibacterial activity against the pathogenic strains of Staphylococcus aureus and Escherichia coli.

Exploring microstructural evolution, nitrogen depth profile, and dry wear performance in 31CrMoV9 steel through combined severe shot peening and plasma nitriding

The present study investigates the influence of severe shot peening (SSP) on the plasma nitriding behavior and sliding wear performance of 31CrMoV9 steel. Initially, the steel was austenitized at 880 °C, followed by oil quenching, and tempering at 520 °C for one hour. These samples were shot peened using high-carbon steel shots, resulting in an enhancement in surface hardness up to 447 HV, gradually converging to the initial martensitic hardness after 140 µm depth. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) scrutinized the initial and surface treated martensitic samples. Afterward, the plasma nitriding treatments were carried out at temperatures of 400 °C, 450 °C, and 500 °C for 8 hours in a 30% N2 + 70% H2 atmosphere and 300 Pa pressure. Microhardness testing, SEM, XRD, and glow-discharge optical emission spectroscopy (GDOES) evaluated both plasma nitrided (PN) and severe shot peened/plasma nitrided (SSP-PN) samples. Cross-sectional SEM observations revealed compound layer thicknesses of approximately 2.8 µm, 5.0 µm, and 6.3 µm for PN samples at 400 °C, 450 °C, and 500 °C, respectively. SSP-PN samples exhibited a substantial increase — roughly 71%, 44%, and 33% increase, respectively, compared to PN samples. GDOES analysis supported this trend and indicated enhanced nitrogen diffusion depth, particularly evident in SSP-PN samples at consistent temperatures. The XRD results showed the stability of Fe4N, Fe2–3N, and CrN phases at all three nitriding temperatures. Furthermore, the intensity of these phases increases with temperature and is augmented by the application of the SSP. Microhardness measurements indicated hardness escalation: from 775 HV to 980 HV at 400 °C, 932 HV to 1096 HV at 450 °C, and 1011 HV to 1205 HV at 500 °C due to SSP. Finally, the wear performance was investigated between the non-nitrided, SSP, PN, SSP-PN, samples. Initially, SSP led to decreased wear performance up to 500 m, followed by improved behavior up to 1500 m. At 400 °C, the SSP-PN sample exhibited a 12% lower wear rate than PN. At 450 °C and 1500 m, the SSP-PN sample displayed a 24% reduction, while at 500 °C, it showed a 27% reduction compared to PN. SEM observations indicated abrasion as the primary wear mechanism across all samples. The overall results indicated a significant similarity in the nitrogen depth profile, hardness depth, and wear performance between the SSP-PN sample at 450 °C and the PN sample at 500 °C. The fact suggested a potential reduction of approximately 50 °C in the typical plasma nitriding temperature for 31CrMoV9 steel as a result of the SSP process.

Research on the epitaxial direction control and mechanism of polycrystalline diamond grains

The control of diamond film growth is crucial for the application of diamond films. In this article, different diamond film samples were prepared by adding nitrogen and oxygen in different proportions during the growth process. The key conditions for controlling the growth of diamond film with preferred orientation were obtained using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy characterizations. During the growth process, the growth of the diamond film with (100) preferred orientation could be achieved by adjusting nitrogen content. It was necessary to introduce nitrogen and oxygen in the growth process, and precisely regulate the ratio of the two to obtain the (111) preferred orientation of the diamond film. When only oxygen was introduced during growth, the preferred orientation of the diamond could not be achieved, leading to a smaller grain size and poorer crystal quality. From the perspective of grain morphology to film morphology evolution, this study obtained the crystal orientation control conditions during the diamond film growth, which has important guiding significance for the application of the diamond film. This study seeks to drive progress in the large-scale growth of readily machinable diamond and the evolution of diamond-grain optical fiber sensing through comprehensive investigations into the correlation between the preferred orientation in polycrystalline diamonds and reaction conditions.

Development of Magnetic Solid Phase Micro-Extraction (MSPE) Method for the Extraction and Preconcentration of the Selected β-Blockers in the Environmental Wastewaters

AbstractEmerging organic pollutants s have always been the greatest environmental concern due to their ubiquity and distinguished adverse effects. These are mostly water-bone pollutants flagged as endocrine disruptors and can greatly inconvenience the ecosystem. Among others, β-blockers have also been detected in the environment at various concentrations that threaten the well-being of humans and animals. In this work, NH2-MIL-101(Cr) doped magnetic nanoparticles nanocomposite was successfully synthesised and characterised using analytical techniques such as X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and transmission electron microscopy (TEM). The Fe3O4@NH2-MIL-101(Cr) was then used as an adsorbent to extract the selected β-blockers in the environmental wastewater. The selected β-blockers were quantified using a high-performance liquid chromatography-diode array detector (HPLC-DAD). Parameters affecting the extraction were screened and optimised using fractional factorial design (FFD) and central composite design (CCD), respectively. Under optimum conditions, the LODs were 0.057 and 0.065 µg L− 1, and LOQs were 0.19 and 0.22 µg L− 1 for acebutolol (ACE) and metoprolol (MET), respectively. The calibration curve exhibited the linearity range of 0.2–1200 µg L− 1 with correlation coefficients of 0.9987 and 0.9968 for ACE and MET, respectively. Repeatability studies demonstrated the %RSD of 0.63 and 0.74% for MET and ACE. At the same time, reproducibility studies displayed the %RSD of 1.057 and 1.178% for MET and ACE, respectively. Spike recovery experiments were carried out to assess the performance of MSPE in real samples, and over 88% of both analytes were recovered. This indicated that the MSPE method could enrich various organic pollutants from different environmental matrices.

Fe-Incorporated Metal-Organic Cobalt Hydroxide Toward Efficient Oxygen Evolution Reaction

AbstractMetal-organic cobalt hydroxide emerges as a cost-effective electrocatalyst for the oxygen evolution reaction (OER) in energy conversion. However, the limited active sites and poor conductivity hinder their large-scale application. This study employed salicylate as a bridging ligand to synthesize iron-incorporated metal-organic cobalt hydroxide. The influence of Fe intercalation on Co(OH)(Hsal) (where Hsal denotes o-HOC6H4COO−) was investigated using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Fe0.2Co0.8(OH)(Hsal) demonstrates remarkable electrocatalytic activity, displaying an OER overpotential of 298 mV at 10 mA cm−2 and a Tafel slope of 57.46 mV dec−1. This enhancement can be attributed to improved charge transfer kinetics and increased active sites. This work highlights the crucial role of Fe in improving the efficiency of Co-based oxygen-evolving catalysts (OECs) and its potential for boosting efficient hydrogen generation in alkaline environments. Graphical Abstract

Crystallization-driven tuneable lasing of perylene doped into the nematic liquid crystal

Versatile devices with tunable capabilities for controlling lasing wavelength and intensity are in high demand. Liquid crystals (LCs) exhibit immense potential for such applications, offering fine-tuning possibilities through external factors. On the other hand, laser technology is currently a research hotspot in optoelectronics, and also in practical applications. The recent market introduction of laser television marks a significant stride toward making such advanced technology accessible in every household. In synergy with laser pumping, the LCs unquestionably can be rediscovered. This study presents a comprehensive investigation into the crystallization phenomenon within a host-guest device, compact in size, free from moving parts, and integrating the liquid crystalline (LC) matrix doped with 3,4,9,10-tetra-(3-alcoxy-carbonyl)-perylene (THCP) dye. The focus lies in examining the influence of varying dye concentrations on multicolor fluorescence, lasing behavior, and device morphology. The systematic analysis of Random Lasing (RL) energy thresholds and the impact of DC voltage on light intensity modulation is demonstrated. Morphological changes were monitored in real-time using optical microscopy techniques, including crossed polarizer, and fluorescence imaging under 450 nm excitation. Utilizing advanced Transmission Electron Microscopy (TEM) techniques, we explore exceptional insights into our set of devices, providing novel information about the THCP crystallization process for the first time in the literature. To gain a comprehensive understanding of the crystal forming and molecular geometry we examined additionally the THCP dye, using X-ray diffraction and Raman spectroscopy. Furthermore, we showcase that varying the pumping energy enables multicolor tuning in the fabricated systems, presenting an attractive feature in the context of laser display technologies.

MOF-derived nanozyme CuOx@C and its application for cascade colorimetric detection of phytosterols.

Phytosterols (PSs), a class of naturally occurring bioactive lipid compounds, have been found to possess a significant cholesterol-lowering effect. In developing countries, the consumption of rapeseed oil is the primary pathway of PS intake for the general population. However, developing low-cost, real-time, and high-throughput screening techniques for PSs remains a challenge. Here, a Cu-based nanocomposite CuOx@C was synthesized via a simple method of the calcination of HKUST-1 and systematically characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The CuOx@C demonstrated excellent peroxidase-like (POD-like) activity, functioning as a peroxidase mimic to facilitate the catalysis of 3,3',5,5'-tetramethylbenzidine (TMB) into its oxidized form (oxTMB), thereby initiating a discernible color response. On the basis of this discovery, a CuOx@C-based colorimetric method for detecting total sterols in rapeseed was successfully constructed via cascade reactions. After optimizing the conditions, the high-throughput screening of total sterols in rapeseed could be completed in only 21min, which significantly facilitated the sensing of PSs. A linear range of 0.6-6mg/g was achieved for the detection of total sterols in rapeseed samples, thereby satisfying the requirements for detection. In addition, due to the high stability of CuOx@C and the specificity of cholesterol oxidase, the developed method had excellent stability and selectivity toward PSs, indicating that this work has huge prospects for commercial application. This innovative work overcomes the limitation of the instrumental method and provides a portable and reliable tool for total sterols detection. It can also facilitate the development of oilseeds with a high content of PSs.

A Gold(I)-Acetylene Complex Synthesised using Single-Crystal Reactivity.

Using single-crystal to single-crystal solid/gas reactivity the gold(I) acetylene complex [Au(L1)(η2-HC≡CH)][BArF4] is cleanly synthesized by addition of acetylene gas to single crystals of [Au(L1)(CO)][BArF4] [L1 = tris-2-(4,4'-di-tert-butylbiphenyl)phosphine, ArF = 3,5-(CF3)2C6H3]. This simplest gold-alkyne complex has been characterized by single crystal X-ray diffraction, solution and solid-state NMR spectroscopy and periodic DFT. Bonding of HC≡CH with [Au(L1)]+ comprises both σ-donation and π-backdonation with additional dispersion interactions within the cavity-shaped phosphine.