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An X-ray analysis of exfoliated MoS2, produced by means of microwave-assisted liquid-phase exfoliation (LPE) from bulk powder in 1-methyl-2-pyrrolidone (NMP) or acetonitrile (ACN) + 1-methyl-2-pyrrolidone (NMP) solvents, has revealed distinct structural differences between the bulk powder and the microwave-exfoliated samples. Specifically, we performed X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements to identify the elements of our exfoliated sample deposited on a Si substrate by drop-casting, as well as their chemical state and its structural crystalline phase. In the exfoliated sample, the peaks pattern only partially resemble the theoretical Miller indices for MoS2. In contrast, the bulk powder's spectrum shows the characteristic peaks of the 2H polytype of MoS2, but with some broadening. Notable is the retention of partial crystallinity in the post-exfoliation phases, specifically in the normal-to-plane orientation, thus demonstrating the effectiveness of microwave-assisted techniques in producing 2D MoS2 and attaining desirable properties for the material. XPS measurements confirm the success of the exfoliation procedure and that the exfoliated sample retains its original structure. The exfoliation process has been optimized to maintain the structural integrity of MoS2 while enhancing its surface area and electrochemical performance, thereby making it a promising material for advanced electronic and optoelectronic applications ranging from energy storage to sensing devices under ambient conditions. [ABSTRACT FROM AUTHOR]

The self-supported Co–Fe LDH@Ni(OH)2 material is successfully prepared on a foam nickel substrate through two hydrothermal processes. The phase structure and microstructure of the electrode material are investigated through X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM) analyses. The electrode materials undergo electrochemical and electrocatalytic tests using an electrochemical workstation. This study demonstrates that the specific capacitance of the Co–Fe LDH@Ni(OH)2 is 2626 mF cm−2 at 1 mA cm−2. Supercapacitors made of LDH@Ni(OH)2 electrode material operate exceptionally well. Both the power density and the energy density are 0.755 mW cm−2 and 32.5 μWh cm−2, respectively. As a catalyst material for electrochemical splitting of water, CoFe-LDH@Ni(OH)2 exhibits distinguished electrocatalytic properties. The overpotential is 242 mV at 50 mA cm−2 in HER, while that is 149 mV at 20 mA cm−2 in OER. Meanwhile, the CoFe-LDH@Ni(OH)2 electrocatalytic material also performs extremely well in the overall water electrolysis testing. The voltage is 1.65 V at 25 mA cm−2, which shows strong cyclic stability. The material provides a reliable guarantee for sustained and stable operation in various application scenarios. [ABSTRACT FROM AUTHOR]

This article conducted a study on ancient bronze coins unearthed in Huxian, Shaanxi, China. It was found that the coins corroded along the eutectoid phase, and there was an obvious corrosion layering phenomenon. From the outside to the inside, they were the outer rust layer, the transition layer and the matrix layer. When analyzing the chemical composition and corrosion products in different regions, various techniques such as metallographic microscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) and electron probe microanalysis (EPMA) were employed. It was determined that the outer rust layer primarily consisted of Cu2(OH)3Cl, while the transition layer was composed of an α phase and a corroded eutectoid phase (with the corrosion product being SnO2). In addition, combined with electrochemical tests, it was found that the rust layer has better protective performance on the substrate. Based on the above results, it is speculated that some ancient bronze cultural relics may have gone through two stages: the first stage is the market transaction stage after the coin casting is completed, and the second stage is the burial soil corrosion stage when the coins circulating in the market become funerary objects. Relevant research provides a certain theoretical basis for the protection of bronze cultural relics. [ABSTRACT FROM AUTHOR]

The low-grade zinc oxide ore was sulfidized to increase the efficiency of flotation, but the effect of pre-sulfidization on the adsorption mechanism of octadecyl amine (ODA) on the smithsonite surface is currently unclear. In this study, the effect of pre-sulfidization on the adsorption mechanism of ODA and the flotation behavior was studied using smithsonite and pre-sulfidized smithsonite as the samples by zeta potential, contact angle measurement, total organic carbon analyzer (TOC), quartz microcrystalline balance (QCM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and micro-flotation tests. Micro-flotation tests showed that the pretreatment of sulfidization could improve the floatability of smithsonite. Zeta potential and contact angle measurements demonstrated that pre-sulfidization could favor the adsorption of ODA, which is further confirmed by the adsorption tests of ODA using TOC and QCM. Furthermore, FTIR and XPS analysis showed that pre-sulfidization changes the adsorption mode of ODA, changing it from physical adsorption to chemical adsorption. These results suggested that the favorable effect of pre-sulfidization on the adsorption of ODA and the flotation of smithsonite might provide important guidance for industrial application. [ABSTRACT FROM AUTHOR]

Formaldehyde (HCHO) is identified as the most toxic chemical among 45 organic compounds found in industrial wastewater, posing significant harm to both the environment and human health. In this study, a novel approach utilizing the Lanthanum-manganese complex oxide (LaMnO3)/peroxymonosulfate (PMS) system was proposed for the effective removal of HCHO from wastewater. Perovskite-Type LaMnO3 was prepared by sol-gel method. The chemical compositions and morphology of LaMnO3 samples were analyzed through thermogravimetric analysis (TG), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The effects of LaMnO3 dosage, PMS concentration, HCHO concentration, and initial pH on the HCHO removal rate were investigated. When the concentration of HCHO is less than 1.086 mg/mL (5 mL), the dosage of LaMnO3 is 0.06 g, and n(PMS)/n(HCHO) = 2.5, the removal rate of HCHO is more than 96% in the range of pH = 5–13 at 25 °C for 10 min. Compared with single-component MnO2, the perovskite structure of LaMnO3 is beneficial to the catalytic degradation of HCHO by PMS. It is an efficient Fenton-like oxidation process for treating wastewater containing HCHO. The LaMnO3 promoted the formation of SO4•− and HO•, which sequentially oxidized HCHO to HCOOH and CO2. [ABSTRACT FROM AUTHOR]

Ag3PO4/g-C3N4 photocatalytic composites were synthesized via calcination and hydrothermal synthesis for the degradation of rhodamine B (RhB) in wastewater, and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS). The degradation of RhB by Ag3PO4/g-C3N4 composites was investigated to evaluate their photocatalytic performance and cyclic degradation stability. The experimental results showed that the composites demonstrated notable photocatalytic activity and stability during degradation. Their high degradation efficiency is attributed to the Z-scheme transfer mechanism, in which the electrons in the Ag3PO4 conduction band and the holes in the g-C3N4 valence band are annihilated by heterojunction recombination, which greatly limits the recombination of photogenerated electrons and holes in the catalyst and enhances the activity of the composite photocatalyst. In addition, measurements of photocurrent (PC) and electrochemical impedance spectroscopy (EIS) confirmed that the efficient charge separation of photo-generated charges stemmed from strong interactions at the close contact interface. Finally, the mechanism for catalytic enhancement in the composite photocatalysts was proposed based on hole and radical trapping experiments, electron paramagnetic resonance (EPR) analysis, and work function evaluation. [ABSTRACT FROM AUTHOR]

A novel graphene-based composite, 5-methyl-1,3,4-thiadiazol-2-amine (MTA) covalently functionalized graphene oxide (GO-MTA), was rationally developed and used for the selective sorption of Ga3+ from aqueous solutions, showing a higher adsorption capacity (48.20 mg g−1) toward Ga3+ than In3+ (15.41 mg g−1) and Sc3+ (~0 mg g−1). The adsorption experiment's parameters, such as the contact time, temperature, initial Ga3+ concentration, solution pH, and desorption solvent, were investigated. Under optimized conditions, the GO-MTA composite displayed the highest adsorption capacity of 55.6 mg g−1 toward Ga3+. Moreover, a possible adsorption mechanism was proposed using various characterization methods, including scanning electron microscopy (SEM) equipped with X-ray energy-dispersive spectroscopy (EDS), elemental mapping analysis, Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Ga3+ adsorption with the GO-MTA composite could be better described by the linear pseudo-second-order kinetic model (R2 = 0.962), suggesting that the rate-limiting step may be chemical sorption or chemisorption through the sharing or exchange of electrons between the adsorbent and the adsorbate. Importantly, the calculated qe value (55.066 mg g−1) is closer to the experimental result (55.60 mg g−1). The well-fitted linear Langmuir isothermal model (R2 = 0.972~0.997) confirmed that an interfacial monolayer and cooperative adsorption occur on a heterogeneous surface. The results showed that the GO-MTA composite might be a potential adsorbent for the enrichment and/or separation of Ga3+ at low or ultra-low concentrations in aqueous solutions. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) has shown significant potential in humidity sensing. It is well accepted that the oxygen-containing functional groups in GO significantly influence its humidity sensing performance. However, the relationship between the content of these groups and the humidity sensing capability of GO-based sensors remains unclear. In the present work, we investigate the role of oxygen-containing functional groups in the humidity sensing performance by oxidizing graphite with mesh numbers 80–120, 325, and 8000 using the Hummers method, resulting in GO-80, GO-325, and GO-8000. Infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS) were used to identify the types and quantification of oxygen-containing functional groups. Molecular dynamics simulation is used to simulate the adsorption energy, intercalation dynamics, and hydrogen bonding of water molecules. Electrochemical tests were used to compare the adsorption/desorption time and response sensitivity of graphene oxide to humidity. It is proposed that hydroxyl and carboxyl groups are the main contributing groups to humidity sensing. GO-8000 shows a relatively fast response time, but the large number of carboxyl groups will hinder intercalation of water molecules, thus exhibiting lower sensitivity. This research provides a reference for the future development of graphene-based sensors, catalysts, and environmental materials. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs) have attracted extensive attention due to their unique catalytic properties and wide range of applications. Advanced characterization techniques, such as energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, and X-ray absorption fine-structure spectroscopy, have been used to investigate the elemental compositions, structural morphologies, and chemical bonding states of SACs in detail, aiming at unraveling the catalytic mechanism. Meanwhile, theoretical calculations, such as quantum chemical calculations and kinetic simulations, were used to predict the catalytic reaction pathways, active sites, and reaction kinetic behaviors of SACs, providing theoretical guidance for the design and optimization of SACs. This review overviews advanced characterization techniques and theoretical calculations for SACs in Fenton-like chemistry. Moreover, this work highlights the importance of advanced characterization techniques and theoretical calculations in the study of SACs and provides perspectives on the potential applications of SACs in the field of environmental remediation and the challenges of practical engineering. [ABSTRACT FROM AUTHOR]

Converting carbon dioxide (CO2) into high-value-added chemicals using solar energy is a promising approach to reducing carbon dioxide emissions; however, single photocatalysts suffer from quick the recombination of photogenerated electron–hole pairs and poor photoredox ability. Herein, silver (Ag) nanoparticles featuring with localized surface plasmon resonance (LSPR) are combined with g-C3N4 to form a Schottky junction for photothermal catalytic CO2 reduction. The Ag/g-C3N4 exhibits higher photocatalytic CO2 reduction activity under UV-vis light; the CH4 and CO evolution rates are 10.44 and 88.79 µmol·h−1·g−1, respectively. Enhanced photocatalytic CO2 reduction performances are attributed to efficient hot electron transfer in the Ag/g-C3N4 Schottky junction. LSPR-induced hot electrons from Ag nanoparticles improve the local reaction temperature and promote the separation and transfer of photogenerated electron–hole pairs. The charge carrier transfer route was investigated by in situ irradiated X-ray photoelectron spectroscopy (XPS). The three-dimensional finite-difference time-domain (3D-FDTD) method verified the strong electromagnetic field at the interface between Ag and g-C3N4. The photothermal catalytic CO2 reduction pathway of Ag/g-C3N4 was investigated using in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS). This study examines hot electron transfer in the Ag/g-C3N4 Schottky junction and provides a feasible way to design a plasmonic metal/polymer semiconductor Schottky junction for photothermal catalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

This study aims to improve the photocatalytic properties of titanium dioxide nanorods (TNRs) and other related nanostructures (dense nanorods, needle-like nanorods, nanoballs, and nanoflowers) by modifying them with silver nanoparticles (AgNPs). This preparation is carried out using a two-step method: sol–gel dip-coating deposition combined with hydrothermal crystal growth. Further modification with AgNPs was achieved through the photoreduction of Ag+ ions under UV illumination. The investigation explores the impact of different growth factors on the morphological development of TiO2 nanostructures by modulating (i) the chemical composition, the water:acid ratio, (ii) the precursor concentration involved in the hydrothermal process, and (iii) the duration of the hydrothermal reaction. Morphological characteristics, including the length, diameter, and nanorod density of the nanostructures, were analyzed using scanning electron microscope (SEM). The chemical states were determined through use of the X-ray photoelectron spectroscopy (XPS) technique, while phase composition and crystalline structure analysis was performed using the Grazing Incidence X-ray Diffraction (GIXRD) method. The results indicate that various nanostructures (dense nanorods, needle-like nanorods, nanoballs, and nanoflowers) can be obtained by modifying these parameters. The photocatalytic efficiency of these nanostructures and Ag-coated nanostructures was assessed by measuring the degradation of the organic dye rhodamine B (RhB) under both ultraviolet (UV) irradiation and visible light. The results clearly show that UV light causes the RhB solution to lose its color, whereas under visible light RhB changes into rhodamine 110, indicating a successful photocatalytic transformation. The nanoball-like structures' modification with the active metal silver (TNRs 4 Ag) exhibited high photocatalytic efficiency under both ultraviolet (UV) and visible light for different chemical composition parameters. The nanorod structure (TNRs 2 Ag) is more efficient under UV, but under visible-light photocatalyst, the TNRs 6 Ag (dense nanorods) sample is more effective. [ABSTRACT FROM AUTHOR]

The effect of carbon contamination on the elemental beta boron (β-B) from the graphite components of spark plasma sintering (SPS) was investigated. The X-ray diffraction, analytical electron microscopy (AEM) and Raman spectroscopy witnessed boron carbide (B 13+x C 2-x where x=0.05–0.35), when SPS temperature was above 1750 °C. The degree of carbon contamination became severe with increasing SPS temperature to 1800 °C and 1850 °C and formed a single-phase rhombohedral boron carbide with about 12 wt% of carbon. Our observations indicate that the carbon gets kinetically trapped into β-B to form boron carbide with a primitive unit cell consisting mainly of icosahedral B 11 C and three-atom chain of CBB configurations. After 6 months of natural aging, it has been revealed that boron carbide formed at and below sintering temperatures of 1800 °C is not a thermodynamically stable phase, and transformed reversibly to β-B structure. X-ray photoelectron spectroscopy ascertained that there are no longer B-C bonds and the existence of more C C bonds in a 6 months aged specimen, suggesting carbon is no longer strongly bonded to boron, but precipitates as graphitic structure. Further examination using atom probe tomography and AEM confirmed the existence of carbon nanoclusters within grains and high concentration of carbon segregating onto grain boundaries. The phase transformation of boron carbide to mostly boron resulted in a significant loss of hardness and modulus in a bulk SPS specimen. This study underscores the importance of solid solution and local bonding environment in icosahedral boron-rich solids for phase stability and sustained properties. [ABSTRACT FROM AUTHOR]

The shear-thickening polishing (STP) method, a flexible polishing technique developed in recent years, was utilized to obtain high surface quality of yttrium aluminum garnet (YAG) crystal effectively. The effect of polishing slurry pH value, which characterizes the chemical action between slurry and YAG crystal, on the material removal rate and surface roughness of YAG crystal was investigated, and the mechanism of the chemical action between YAG and slurry in STP process was revealed through X-ray photoelectron spectroscopy (XPS) analysis. The influence of polishing speed and abrasive concentration, which were relating with mechanical action, on the polishing effects was also studied. The experimental results show that when the pH value of the polishing slurry is lower than 11, the dissociation of chemical bonds and the formation of new bonds on the surface of the YAG crystal are predominantly found, resulting in a lower material removal rate. While the pH value of polishing slurry reaches 13, a reaction layer consisting of Al 2 SiO 5 and Y 2 SiO 5 , which has lower hardness than abrasive, is formed on the surface, and this reaction layer can be removed by mechanical action efficiently. The surface roughness S a decreases from 60 ± 10 nm to 0.38 ± 0.06 nm in 15 min with MRR reaches 117.30 nm/min, which is 4.3 times higher than that of chemical mechanical polishing. Based on the results of XPS analysis, the material removal mechanism of YAG polished by STP is proposed. As revealed by the results, STP with chemical action provide a high efficiency polishing method for the high surface quality YAG crystal. [ABSTRACT FROM AUTHOR]

In this work, spherical-like ZnO nanoparticles (NPs) were synthesized via avocado seed extract and calcined at 400 °C, which exhibited a hexagonal wurtzite structure with an average size of around 42 nm. The chemical states, organic residuals, and defects were confirmed by X-ray photoelectron spectroscopy (XPS). The ZnO NPs-based memristors exhibited remarkably stable analog switching, over 300 continuous cycles, and a wide operating window of 400. Moreover, the asymmetry in the current observed was attributed to the self-rectifying nature of this device, comprising one analog memristor and one Schottky diode (1D–1R). By controlling the peak voltage to 4 V and applying 50 bias pulses, it was possible to effectively imitate the key features of synaptic behavior, including potentiation and depression, through current modulation. [Display omitted] • The Cr/ZnO/FTO memristors based on green synthesized ZnO NPs demonstrate stable analog resistive switching over 300 operating cycles and a 400-ON/OFF ratio window. • The self-rectifying property of the memristor originates from the Schottky diode at the Cr/ZnO junction. • The synaptic behavior showcases non-volatile properties and emulates synapse-like characteristics. [ABSTRACT FROM AUTHOR]

As we know, the ligands on the surface of core/shell structured quantum dots (QDs) play an important role. They not only bind with metal ions to passivate surface defects but also have a great influence on colloidal stability. All-organic or all-inorganic ligands afford QDs with some disadvantages such as low conductivity, poor dispersibility and undesirable stability. By combining with the advantages of organic and inorganic ligands, herein, we achieve an organic/inorganic hybrid surface passivation through exchanging partial oleic acid ligands with chlorine ions (Cl−), affording QD with a core/shell structure of CdZnSe/ZnSe/ZnS/OACl. It exhibits an excellent nanostructure with a mean size of around 11.6 nm. According to X-ray photoelectron spectroscopy (XPS) spectra, around 30% oleid acid ligands are removed by Cl−, resulting in the hybrid surface passivation. The CdZnSe/ZnSe/ZnS/OACl QD exhibit an efficient green emission at the wavelength of around 535 nm with a quantum yield of over 90%. The QD light-emitting diode (QLED) based on CdZnSe/ZnSe/ZnS/OACl exhibits a peak EQE of 15.6% and a brightness of over 1.1 × 105 cd m−2 at 6 V, corresponding to an efficient green emitting device. Therefore, we believe that the hybrid surface passivation could provid a reliable avenue to efficient QD materials. [ABSTRACT FROM AUTHOR]

Yttrium oxide (Y 2 O 3) nanoparticles have critical applications in many industries, including ceramics, optics, and biomedicine. However, conventional synthesis methods are typically cumbersome and time-consuming. Herein, a novel emulsion detonation method successfully achieved the one-step synthesis of Y 2 O 3 nanoparticles. In this method, yttrium nitrate hexahydrate was uniformly dispersed in the emulsion explosive as a precursor and an auxiliary oxidizer. After the emulsion explosive was detonated in a detonation chamber, the detonation products were collected, purified and characterized by X-ray diffraction, Fourier transform infrared spectrometer, Raman spectrometer, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, field emission transmission electron microscopy, and ultraviolet spectrophotometer. The results show that the as-synthesized powders are high-purity cubic phase yttrium oxide nanoparticles with a spherical-like morphology and an average particle size of approximately 30 nm. These Y 2 O 3 nanoparticles have a wide (5.53 eV) energy band gap, close to the conventional methods. Based on detonation theory, thermochemical theory, and characterization results, this text discussed the mechanism of the Y 2 O 3 nanoparticles synthesized by the emulsion detonation method. During detonation, the formation of the Y 2 O 3 nanoparticles underwent three stages: the formation of the Y 2 O 3 molecules by the collision of Y and O ions, the formation of the crystal nucleus at supersaturation concentration, and crystal growth. This study provides a novel, cost-effective method for efficiently synthesizing Y 2 O 3 nanoparticles. [ABSTRACT FROM AUTHOR]

To endow SiC ceramic membranes a catalytic self-cleaning capability, a pore-functionalized SiC ceramic membrane with impregnated a perovskite-type catalyst La 0 · 8 Mn 0 · 2 FeO 3 was fabricated by a urea-assisted one-step combustion method. Diffraction of X-ray (XRD), canning electronic microscopy (SEM) with an energy dispersion X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were employed to investigate the effects of the impregnating of La 0 · 8 Mn 0 · 2 FeO 3 on SiC membrane pore-structure (La 0 · 8 Mn 0 · 2 FeO 3 -CM). The catalytic self-cleaning performance of the as-prepared membranes was assessed through peroxymonosulfate (PMS) activation under a cross-flow filtration mode. Results indicate that La 0 · 8 Mn 0 · 2 FeO 3 has been successfully impregnated into the macropores of SiC membranes without pore blocking, and 92.4 % of the flux recovery rate (FRR) was achieved when the PMS concentration was 70 mM and catalytic flushing time was 45 min. Therefore, the La 0 · 8 Mn 0 · 2 FeO 3 impregnated SiC membrane exhibited excellent catalytic self-cleaning property, which can effectively avoid the environmental pollution and the deterioration of membrane materials caused by chemical cleaning for membrane fouling. In addition, the radical quenching experiment and electron spin resonance (EPR) tests were conducted in the catalytic self-cleaning process, and the results suggested that the hydroxyl radical (⋅OH) and sulfate radical (SO 4 •‾) are simultaneously captured and ⋅OH is the dominant active species. This study embarks on a novel and environmental friendly membrane cleaning approach for irreversible fouling eliminates in diverse membrane separation applications. • A SiC ceramic membrane with catalytic self-cleaning function was prepared and characterized. • La 0 · 8 Mn 0 · 2 FeO 3 exhibited high-effective PMS activation performance. • FRR of 92.4 % was achieved in the La 0 · 8 Mn 0 · 2 FeO 3 -CM/PMS system. • Oxidant species were captured and identified in the catalytic self-cleaning process. [ABSTRACT FROM AUTHOR]

Sol-gel auto ignition route was utilized to synthesize a series of Zn-doped Cd–Mg spinel ferrites with composition Cd 0.5-x Mg 0.5 Zn x Fe 2 O 4 (x = 0.0, 0.1, 0.2, and 0.3). All of the prepared nanomaterials that were annealed for 4 h at 900 °C had a cubic structure and were spinel, according to X-ray diffraction studies. The lattice constant decreased as the Zn concentration increased. This is because of the substituent's lower radii. The W–H plot, Size strain plot, and Sherrer Formula were used to calculate the crystallite size, which was in the range of a nanometer. Vibrational spectroscopy studies have also shown that M − O bonds are present in every processed sample and that a spinel cubic structure has formed. Additionally, the cationic distribution and cubic spinel structure were validated by Rietveld refinement of the XRD data. The analysis using X-ray photoelectron spectroscopy (XPS) has confirmed the presence of all metal ions in their respective electronic states. The dielectric characteristics in the 1 MHz-6 GHz range of frequencies were ascertained using an impedance analyzer. Jonscher's power law validated the conduction mechanism in the synthesized ferrite samples. The relaxation time constant calculated from impedance Cole-Cole plots shows that the conduction in all the synthesized nanomaterials was due to the grains rather than the grain boundaries. The minimum reflection loss of −36.54 dB was achieved for Zn-doped Cd–Mg ferrites at x = 0.3. The prepared Zn-doped Cd–Mg spinel ferrites would be an excellent material for high-frequency microwave absorption applications. [ABSTRACT FROM AUTHOR]

The severe stress on the surface of the wide-bandgap perovskite film will extend to the carrier transport layer (CTL)/metal electrode interface, leading to increased roughness of the CTL surface. This, in turn, adversely affects carrier transfer at the interface and compromises device stability. To address this issue, we devised a localized contact structure wherein molybdenum oxide (MoOx) interlayers of specific thickness were vacuum-deposited at the CTL/metal electrode interface to change the path of carrier transfer. Characterizations of the MoOx localized contact structure were done by Kelvin probe force microscopy, capacitance–voltage (C–V), electrochemical impedance spectroscopy, and x-ray photoelectron spectroscopy. It was observed that MoOx interlayer can generate negative fixed charges at hole transport layer/Ag interface, which changes the carrier concentration distribution, enhances the built-in voltage, and promotes the transfer of carriers near the interface. Compared to wide-bandgap perovskite solar cells (WB-PSCs, Eg = 1.65 eV) lacking the MoOx localized contact structure, the efficiency of the optimized device increased to 20.5%, accompanied by enhancements in overall performance parameters. Notably, the thermal and light stability of the unpackaged devices have been significantly improved. [ABSTRACT FROM AUTHOR]

Membrane wetting caused by substances in the feed solution with low surface tension has posed serious issues for membrane distillation (MD). Omniphobic membranes could be helpful when dealing with this problem because they strongly repel liquids with a wide range of surface tensions. We fabricated electrospun omniphobic membranes containing PVDF‐TEOS‐PFDTMS, PVDF‐HFP‐TMOS‐PFDTMS, and PVDF‐HFP‐TEOS‐PFDTMS. All electrospun membranes have shown contact angles >90°, but the electrospun membrane containing PVDF‐HFP‐TEOS‐PFDTMS has shown super repellence with a contact angle >150° and maintains stable salt rejection and water flux in direct contact MD processes in the presence of sodium dodecyl sulfate surfactant (up to 0.3 mM). Furthermore, the morphology and crystallinity of the electrospun membranes were studied by scanning electron microscopy and Fourier‐transform infrared spectroscopy, and the percentage composition of elements was analyzed by x‐ray photoelectron spectroscopy. liquid entry pressure, mechanical strength, and the porosity of the electrospun omniphobic membranes were also studied. [ABSTRACT FROM AUTHOR]

Qatar's population has been rapidly increasing in recent years, and the country's long-term vision, QNV 2030, aims to sustain this growth by transforming the country into a sustainable state. One aspect of this vision is to convert waste into value-added products, which will reduce the environmental and spatial burden associated with waste in Qatar, while contributing to a circular economy. This study describes methods for producing biochar and activated carbon (AC) from gas-to-liquids derived biosolids, cardboard waste and mixed samples using pyrolysis and activation techniques. The characterisation of products revealed that the yield of biochar samples was higher than AC, and that the pH of the biochar samples was more alkaline than the feed samples due to metals after pyrolysis and reduced acid surface functional groups. Proximate analysis of samples showed lowered moisture and enhanced ash in feeds upon pyrolysis and activation due to increased temperature with reduced volatile content. AC application to water treatment is considered a potential benefit due to the increased surface area, pore volume and magnetic properties based on the Brunauer–Emmett–Teller (BET) and X-ray Powder Diffraction (XRD) analysis. The X-ray photoelectron spectroscopy (XPS) analysis also showed increased –CO3/O–C = O and potassium in the ACs as a result of potassium carbonate activation. The study proposes various applications that can support a circular economy, but future studies should investigate actual applications and potential health and environmental effects and evaluate the feasibility and environmental impact of production methods. [ABSTRACT FROM AUTHOR]

In this study, magnetically recyclable spherical Fe3O4/Cu2O particles comprising S-scheme heterojunctions were prepared by a simple hydrothermal approach using n-type semiconductor Fe3O4 as precursor and p-type semiconductor Cu2O. A Fenton-like system was thus constructed via the addition to Fe3O4/Cu2O of hydrogen peroxide. A rhodamine B (RhB) solution was used to simulate polluted wastewater, and photocatalytic RhB removal experiments were conducted under visible light irradiation. Powder X-ray diffractometry, vibrating-sample magnetometry, nitrogen adsorption–desorption, transmission electron microscopy, and X-ray photoelectron spectroscopy experiments were conducted to characterise Fe3O4 and Fe3O4/Cu2O composite. The band gap of Fe3O4/Cu2O was 1.76 eV, narrower than that of Fe3O4 (2.14 eV). The effects of the pH, sample dosage, hydrogen peroxide concentration, and RhB initial concentration on RhB removal were investigated. According to evidence, under the optimum reaction conditions, the RhB removal rate was 99.4%. The Fe3O4/Cu2O composite exhibited good photocatalytic efficacy even after four cycles of testing. Based on the results of free radical capture experiments, hydroxyl radicals and holes cooperated as main reactive species in the photocatalytic system. The Fe3O4/Cu2O photocatalyst can be easily removed based on magnetism, and it has been proven to be very effective for the degradation of RhB under both UV and visible light irradiation. [ABSTRACT FROM AUTHOR]

In cold regions, saline soils can cause dissolution, settlement, and salt expansion of the roadbed under the influence of freeze–thaw cycles, so they need to be stabilized during road construction. In this study, lime, fly ash (FA), and polyacrylamide (PAM) were used to stabilize sulfate saline soils, and the stabilized saline soils were subjected to the unconfined compressive strength test (UCS), splitting test, and freeze–thaw cycle tests (FTs). The stabilization mechanism of the three materials on saline soils was also studied via scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS). The test results showed that the addition of lime, FA, and PAM to saline soils can improve the mechanical properties and frost resistance of saline soils. After 28 d of curing, the UCS of FA-, PAM-, and lime-stabilized saline soils increased by at least 55%, 23%, and 1068%, respectively, and the splitting strength increased by at least 161%, 75%, and 2720%, respectively. After five freeze–thaw cycles, the residual strength ratios (BDRs) of the UCS of L2 (lime 8%), F2 (FA 11%), and P2 (PAM 1%) stabilized soils and saline soils were 71.78%, 56.42%, 39.05%, and 17.95%, respectively, and the decreasing trend tended to be stable. The saline soils stabilized by lime and FA were chemically stabilized, and their mechanical properties and frost resistance were better than the physical stabilization of PAM. [ABSTRACT FROM AUTHOR]

The prolonged duration of phytoremediation poses a risk of heavy metal dispersal to the surrounding environment. This study investigated a combined remediation approach for cadmium (Cd)- and arsenic (As)-contaminated soil by integrating phytoremediation with stabilization techniques. Bidens pilosa was utilized as the phytoremediator, and steel slag, pyrolusite, and FeSO4 were employed as stabilizing agents in the pot experiments. Key metrics such as soil moisture content, root length, plant height, and heavy metal concentrations in Bidens pilosa were measured to evaluate the remediation efficacy. Additionally, the bioavailability, leaching toxicity, and chemical forms of Cd and As, along with other soil properties, were analyzed. The results indicated that the optimal restoration effect was achieved by combining steel slag, pyrolusite, and FeSO4 with stabilizers in a ratio of 2:1:10. Additionally, the optimal dosage of these materials was found to be 9% by weight. Mechanistic studies, including heavy metal speciation analysis, X-ray photoelectron spectroscopy (XPS), and microbial community diversity analysis, revealed that the stabilization effects were primarily due to the interactions of anionic and cationic ions, chelation by organic acids secreted by plant roots, and enhanced microbial activity. A cost–benefit analysis demonstrated the technical, economic, and commercial viability of the combined remediation approach. [ABSTRACT FROM AUTHOR]

The mass production of high-quality graphene is required for industrial application as a future electronic material. However, the chemical vapor deposition (CVD) systems previously studied for graphene production face bottlenecks in terms of quality, speed, and reproducibility. Herein, we report a novel conveyor CVD system that enables rapid graphene synthesis using liquid precursors. Pristine and nitrogen-doped graphene samples of a size comparable to a smartphone (15 cm × 5 cm) are successfully synthesized at temperatures of 900, 950, and 1000 °C using butane and pyridine, respectively. Raman spectroscopy allows optimization of the rapid-synthesis conditions to achieve uniformity and high quality. By conducting compositional analysis via X-ray photoelectron spectroscopy as well as electrical characterization, it is confirmed that graphene synthesis and nitrogen doping degree can be adjusted by varying the synthesis conditions. Testing the corresponding graphene samples as gas-sensor channels for NH3 and NO2 and evaluating their response characteristics show that the gas sensors exhibit polar characteristics in terms of gas adsorption and desorption depending on the type of gas, with contrasting characteristics depending on the presence or absence of nitrogen doping; nitrogen-doped graphene exhibits superior gas-sensing sensitivity and response speed compared with pristine graphene. [ABSTRACT FROM AUTHOR]

In the present work, a La-based sealing procedure was developed for the anodized AZ31B magnesium alloy. The effects of sealing time and temperature on the electrochemical behavior of the samples were investigated. The corrosion resistance was evaluated in 3.5 wt.% NaCl solution using potentiodynamic polarization tests. Scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) were used to examine the morphology and composition of the sealing films. The results were discussed based on the interplay between film composition, morphological aspects and surface roughness. The best corrosion resistance was obtained for the sample sealed for 20 minutes at 50 °C that exhibited the widest passive range, surpassing that of the anodized (unsealed) sample by more than three times. As indicated by the SEM and XPS results, the formation of a uniform sealed layer comprised of a mixture of La2O3 and La(OH)3 enhanced the corrosion resistance of the anodized AZ31B. [ABSTRACT FROM AUTHOR]

Crystalline zeolites have high acidity but limited utility due to microporosity, whereas mesoporous amorphous aluminosilicates offer better porosity but lack sufficient acidity. In this work, we investigated defect engineering to fine-tune the acidity of amorphous acidic aluminosilicates (AAS). Here we introduced oxygen vacancies in AAS to synthesize defective acidic aluminosilicates (D-AAS). 1H, 27Al, and 17O solid-state nuclear magnetic resonance (NMR) studies indicated that defects induced localized structural changes around the acidic sites, thereby modifying their acidity. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy studies substantiated that oxygen vacancies alter the chemical environment of Brønsted acidic sites of AAS. The effect of defect creation in AAS on its acidity and catalytic behavior was demonstrated using four different acid-catalyzed reactions namely, styrene oxide ring opening, vesidryl synthesis, Friedel-Crafts alkylation, and jasminaldehyde synthesis. The defects played a role in activating reactants during AAS-catalyzed reactions, enhancing the overall catalytic process. This was supported by in-situ FTIR, which provided insights into the molecular-level reaction mechanism and the role of defects in reactant activation. This study demonstrates defect engineering as a promising approach to fine-tune acidity in amorphous aluminosilicates, bridging the porosity and acidity gaps between mesoporous amorphous aluminosilicates and crystalline zeolites. Is it possible to fine-tune the acidity of amorphous aluminosilicates? Here authors use defect engineering as a method to optimize acidity, bridging the porosity and acidity gaps between amorphous aluminosilicates and crystalline zeolites. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) with their exceptional properties have the potential to revolutionize the field of electrochemistry and pave the way for new and exciting applications. MOFs is an excellent choice as an active electrocatalyst component in the fabrication of electrochemical sensors. Here, bimetallic NiCo-MOFs, monometallic Ni-MOFs, and Co-MOFs were fabricated to modify the carbon paste electrode. Moreover, the ratio between Co and Ni within the bimetallic MOFs was optimized. Our aim in this work is to synthesize different compositions from bimetallic MOFs and systematically compare their catalytic activity with mono-metallic MOFs on paracetamol. The structure and properties of the 2D NiCo-MOFs were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared, and electrochemical method. Bimetallic Ni0.75Co0.25-MOFs modified carbon paste sensor displayed the optimum sensing performance for the electrochemical detection of paracetamol. A linear response over the range 6.00 × 10− 7 to 1.00 × 10− 4 M with a detection limit of 2.10 × 10− 8 M was obtained. The proposed method was applied to detect paracetamol in spiked human plasma and to determine paracetamol in the presence of its major toxic impurity, p-aminophenol. These findings suggest the considerable potential use of the newly developed sensor as a point-of-care tool for detecting paracetamol and p-aminophenol in the future. [ABSTRACT FROM AUTHOR]

The origin of elemental chromium for the archaeological weapons from the pits of Qin terracotta warriors in China has been highly controversial. Although previous studies have highlighted that the chromium on the surface of weapon originated from the contamination of surrounding lacquer, the exact origin of chromium in the lacquer remains unclear. In this work, the measurement by inductively coupled plasma-mass spectrometer (ICP-MS) firstly confirmed that the elemental chromium was indeed contained in the archaeological Qin original lacquer. Nevertheless, the amount of elemental chromium in the Qin lacquer was as low as 0.0759 μg/mg, disclosing that it was impossible to artificially add extra refined chromium-containing substance to the lacquer in the preparation of the terracotta warriors. The soil from the archaeological site of Qin lacquer was found to have a chromium amount of 0.0660 μg/mg by ICP-MS. After the hygrothermal and soil-buried aging cycles for the lab-prepared lacquer, the surface and depth elemental analyses by time of flight-secondary ion mass spectrometer (TOF–SIMS) showed a gradient distribution of elemental chromium from the surface to interior of aged lacquer, indicating the migration and enrichment behavior of elemental chromium from the burial soil towards the lacquer. To explore the migration mechanism of elemental chromium, fluorescence imaging technique was employed in combination with Fourier transform infrared spectrometry (FT-IR) and X-ray photoelectron spectroscopy (XPS) characterizations. The results revealed that catechol-containing fragments were formed during hygrothermal and soil-buried aging of lacquer and consequently coordinated with chromium ions, inducing the migration of elemental chromium towards the lacquer. [ABSTRACT FROM AUTHOR]

This study systematically analyzed the effects of Fe3+ ion doping and annealing treatment on the properties of ammonium dihydrogen phosphate (ADP) crystals. X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICP-MS), and energy-dispersive X-ray (EDX) spectroscopy confirmed the concentrations of Fe3+ ions in the pyramid (PY) and prism (PR) face, with doping levels ranging from 10 ppm to 30 ppm. Raman spectroscopy analysis indicated that the ADP crystal's fingerprint peak at 924 cm−1 shifted to a lower wavenumber as the Fe3+ doping concentration increased from 10 ppm to 30 ppm, illustrating lattice distortions caused by doping. Fourier-transform infrared (FTIR) spectroscopy further confirmed these changes, with the crystal fingerprint peak at 967 cm−1 shifting in two opposite directions due to doping with Fe3+ and annealing. The results from positron annihilation lifetime spectroscopy (PALS) indicated that the τ1 values for the annealed samples decreased from 0.135–0.153 ns to 0.123–0.147 ns, suggesting that annealing reduced the concentration of small-sized defects. Meanwhile, τ2 values for the untreated samples decreased from 0.635–0.671 ns to 0.589–0.696 ns, indicating that annealing reduced the number of large-sized defects. Ultraviolet-visible–near-infrared spectroscopy analysis showed that in the wavelength range of 240–800 nm, the average reflectance of the untreated samples was 15–30% higher than that of the annealed ADP crystals, with the reflectance of the latter converging and the variation reducing to below 5% after annealing. These findings suggest that by controlling the growth concentration of Fe3+ ions and optimizing the annealing process, the internal defects within the crystals can be effectively controlled, thereby improving their optical uniformity and mechanical properties, which in turn enhances the performance in nonlinear optical applications. [ABSTRACT FROM AUTHOR]

Schottky barrier height (SBH) enhancement directly translates into increased breakdown voltage (VBR) of β-Ga2O3 Schottky barrier diodes (SBDs). In this work, ultra-thin (5, 10, and 15 Å) oxygen-rich AlOx interfacial layers (ILs), deposited using plasma-enhanced atomic layer deposition, are shown to enhance the SBH of post-metallization oxygen annealed Pt/AlOx/β-Ga2O3 SBDs by up to 0.8 eV resulting in a maximum VBR of nearly 500 V (2× gain) on 2–4 × 1016 cm−3 doped substrates, without compromising the specific on-resistance. The SBH and VBR enhancement is observed on ( 2 ¯ 01) as well as (001) surfaces. X-ray photoelectron spectroscopy (XPS) analysis shows that excess oxygen interstitial concentration in 5 Å AlOx films decreases (increases) with increasing thickness (oxygen anneal), making them more stoichiometric. The decreasing (increasing) trend in SBH and VBR with increasing IL thickness (oxygen anneal) is consistent with the XPS-derived O/Al ratio of the films and the formation of an AlOx/β-Ga2O3 interfacial dipole due to a difference in oxygen areal densities. The AlOx deposition can be easily integrated with field management methods such as field plates and guard rings that can further enhance β-Ga2O3 SBD performance. [ABSTRACT FROM AUTHOR]

Structural property is becoming a powerful tool to manipulate oxygen vacancy concentration and electrochemical performance of electrode material. In this work, the structure-electrochemical performance relationship of Sr 2 (Fe 1-x V x)MoO 6 (x = 0, 0.1, 0.2 and 0.25) anode is investigated based on X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Energy Dispersive Spectrometer (EDS), BET surface area, DC four-point probe, I–V and electrochemical impedance spectra (EIS). XRD results show that all the compounds are of single phase, the tetragonal to cubic phase transition occurs at x = 0.1, which plays important role in its electrochemical performance. Firstly, the disappeared structural distortion in Sr 2 (Fe 1.8 V 0.2)MoO 6 and Sr 2 (Fe 1.75 V 0.25)MoO 6 anodes benefits electron hopping between Fe–O–Mo–O–Fe, so electron transfer processes (high-frequency semicircle) in their EIS are facilitated. Secondly, both XPS survey and EDS spectrum confirm the change in oxygen content with structural transition, Sr 2 (Fe 1.9 V 0.1)MoO 6 anode own higher concentration of oxygen vacancy, thus the oxygen surface exchange and diffusion process (low-frequency arc) of the corresponding cell is reduced significantly. Consequently, Sr 2 (Fe 1.9 V 0.1)MoO 6 -based cell exhibits the highest power output (810 mW cm−2) at 850 °C. For Sr 2 (Fe 1.8 V 0.2)MoO 6 anode, BET surface area test reveals the slightly higher value, while its lower power density indicates that the influence of oxygen vacancy prevails over that of microstructure. Combining with EIS results, it can be deduced that Sr 2 (Fe 1-x V x)MoO 6 anodes with tetragonal symmetry own higher concentration of oxygen vacancy, thus the expected electrochemical performance is better than that of other cells. Understanding the critical role of structure is important for achieving highly active electrode material. • Electrochemical performance of Sr 2 (Fe 1-x V x)MoO 6 changes significantly with structural transition. • Conductivity of Sr 2 (Fe 0.9 V 0.1)MoO 6 is enhanced significantly by V doping. • Sr 2 (Fe 0.9 V 0.1)MoO 6 anode depicts the best electrochemical performance. [ABSTRACT FROM AUTHOR]

A facile strategy to construct superhydrophobic coatings was carried out by one‐pot process using novel nano zero‐valent iron and hydrogen peroxide as trigger in ethanol and Tris buffer mixed system containing dopamine and 1H,1H,2H,2H‐perfluorodecanethiol (PFDT) for the first time. The polydopamine (PDA) modified by PFDT composite coating can be deposited onto various substrates including glass slides, polyurethane sheets, polytetrafluoroethylene wafers, 304 stainless steel sheets, and polyurethane sponges, revealing excellent hydrophobicity with the water contact angles from 157.1° to 162.2° and the sliding angle lower than 1°. The flourier transformed infrared spectroscopy and x‐ray photoelectron spectroscopy information of the composite coating demonstrated the successful covalent interaction between catechol group in PDA and thiol group of PFDT via Michael addition reaction. As‐prepared PFDT/PDA composite coatings exhibited enhanced chemical stability in highly acidic solutions for 6 days, alkaline aqueous solutions for 5 days, salty solutions (3.5 wt%) for 28 days, and polar organic solvents for 24 h, respectively, as well as resistance to algae adhesion. The excellent corrosion resistance and chemical stability of the composite coating and their simple, time saving and inexpensive construction process are expected to be widely applied in various areas, including marine anti‐corrosion, anti‐fouling, and oil–water separation. [ABSTRACT FROM AUTHOR]

Background: As a vital soil-borne pathogenic bacterium, Ralstonia solanacearum can cause wilt disease in multiple Solanaceae plants. Several phages, such as ϕPB2, could infect R. solanacearum acting as a potential biological control agent in soil. In addition, some nanoparticles, especially copper preparation, also showed high toxicity on R. solanacearum with low toxicity on plant. However, whether they can be administered in combination and how effective they are in inhibiting the plant disease caused by R. solanacearum is known very little. Results: In this work, the characterization of CuONPs using scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction ascertained the presence of CuONPs which were nanometer particle of 83 nm. Then it was found that combined application of CuONPs with phage (ϕPB2) was superior to that of ϕPB2 or CuONPs alone in controlling tobacco bacterial wilt, with the CuONPs (250 mg/mL) and phage (106 PFU/mL) ratio being the best, at 79.1%. The combination of CuONPs and ϕPB2 also showed no obvious toxicity on tobacco growth than control like single application of CuONPs or ϕPB2. Furthermore, the transcriptome changes of R. solanacearum analysis indicated that the combination application and single allocation of CuONPs could inhibit "biofilm formation", molecular function, biological processes, cellular components, metabolic process, and so on. In addition, the combination application showed higher inhibition of motility and biofilm, and better enhancement of cell membrane permeability, protein leakage, MDA concentration, and enzyme activity of their respiratory chain dehydrogenase than single application of CuONPs or phage (ϕPB2). Transcriptomes analysis also supported that the addition of ϕPB2 enhanced the toxicity of CuONPs by influencing the ABC transporters and quorum sensing, metabolic processes, and cellular biosynthetic processes of R. solanacearum. Conclusion: In total, our work not only proposed a novel way to increase the bactericidal effect of nanomaterials by adding phage, but also discovered the influence, synergistic effects, and mechanisms, which is useful to design novel way to combat phytopathogenic bacteria in the complicated environment. [ABSTRACT FROM AUTHOR]

Film heterostructures of compositions Ag/Au/Ti and Ag/Au/CFR-PEEK are obtained by thermal evaporation with subsequent deposition of metallic gold sublayers and silver nanostructures on modern biomaterials (Ti-6Al-4V alloy, polyether ether ketone CFR-PEEK). Silver concentration is varied within 2.1-20.8 µg/cm2 by changing the initial metal portion (1.2-5 mg) and the number of successive depositions (1–3). According to SEM data, Ag nanofilms with a thickness up to 10-15 nm are formed on the surface of gold sublayers. According to XPS results, gold is present in the metallic state on the surface of biomaterials whereas along with metal, the Ag2O oxide phase is detected for silver. The dynamics of silver dissolution from the Ag/Au surface is analyzed by ICP-AES (2-48 h). It is found that regardless of the silver concentration, the samples demonstrate moderate dynamics of releasing metal ions; some amount of gold is detected together with silver in the solution. The absence of cytotoxicity of the synthesized film heterostructures in vitro (L-929 cells, viability >95-98%) is shown. Heterostructures completely suppress the growth of colonies of Gram-negative (P. aeruginosa) and Gram-positive (S. aureus) bacteria after 6 h and 24 h action respectively. [ABSTRACT FROM AUTHOR]

In this paper, a new pyrazole derivative, namely, (2-(((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amino)-5-nitrophenyl)(phenyl) methanone (2-DPM) was uniquely used as an inhibitor of corrosion for carbon steel (C-S) in acidic solution (1 M HCl). Numerous techniques include electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), surface morphology analysis (SEM), energy-dispersive X-ray spectrometry (EDX), atom force microscopy (AFM), angle of contact, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible analysis. Molecular dynamic simulations (MDs) and quantum chemical computations (DFT) were utilized to assess the 2-DPM ability. The results show that the inhibitor, acting in a mixed inhibitory mode, considerably reduces the incidence of C-S corrosion by protecting the metal surface with an effective protective layer. The chemically adsorbed novel pyrazole (2-DPM) molecule has an improved corrosion performance of nearly 96% at 303 K, which is supported by EIS and theoretical analyses. The Langmuir isotherm model was shown to regulate the adsorption of 2-DPM on the surface of C-S. Finally, there is a strong correlation between theoretical research and experimental findings. [ABSTRACT FROM AUTHOR]

Cation-disordered rocksalt (DRX) oxides show promise as lithium-ion battery cathodes due to their high theoretical capacity derived from anionic redox. However, the challenges of poor anionic redox reversibility, causing oxygen loss and voltage hysteresis, lead to rapid capacity decay. This study employs a dual-functional urea treatment on Li1.2Ti0.4Mn0.4O2 DRX cathodes, generating oxygen vacancies in the subsurface and a protective carbon nitride layer on the surface through interface reactions. Characterization via X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy confirms these alterations. The presence of oxygen vacancies reduces the average Mn valence, increasing the capacity contributed by Mn and enhancing the reversibility of anionic oxygen redox, thus curbing oxygen loss. Additionally, the carbon nitride layer curtails the parasitic reaction between active oxygen species and the electrolyte. Urea-treated Li1.2Ti0.4Mn0.4O2 exhibits enhanced electrochemical performance, retaining a higher capacity (151 mAh⋅g−1, 80.3% of capacity retention) after 50 cycles compared to neat Li1.2Ti0.4Mn0.4O2 (117 mAh⋅g−1, 64.6% retention). Furthermore, the treatment improves lithium-ion diffusion and rate capability. This dual-functional urea approach presents a promising strategy for enhancing DRX cathode materials and advancing high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Baicalin (Bn) is one of the flavonoids with various biological activities, and its accurate determination is of great significance to clinical medicine. The new "MOF-on-MOF" materials have a broad application prospect. ZIF-67 and MIL-101(Fe) are typical metal–organic frame (MOF) materials, which have the advantages of flexible structure, large specific surface area, large porosity, and adjustable pore size. In this paper, a disposable and sensitive Bn electrochemical sensor based on ZIF-67/MIL-101(Fe) composite modified carbon paper (CP) electrode was developed for the first time. The sensing nanomaterials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) was used to evaluate the electrochemical behavior of Bn on different modified electrodes. The results showed that ZIF-67/MIL-101(Fe)/CP exhibited a well-defined redox peak compared with bare CP, ZIF-67/CP, and MIL-101(Fe)/CP, which was attributed to the synergistic effect of ZIF-67 and MIL-101(Fe). Under optimal conditions, the electrochemical sensor was able to quantify Bn in the ranges of 0.01 ~ 3 µM and 3 ~ 6 µM with a detection limit (LOD) as low as 0.009 µM (S/N = 3). In addition, the sensor was successfully used for the quantitative analysis of Bn in Dual yellow oral liquid with reliable results. [ABSTRACT FROM AUTHOR]

Nanododecahedral ZIF-67 crystals were successfully synthesized by a simple coprecipitation method at room temperature and constructed with graphene oxide (GO) and Nafion as an electrochemical sensing platform for Cu2+. The properties of the electrode and the modified materials were analysed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), square wave stripping voltammetry (SWSV), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental results show that the ZIF-67/GO/Nafion/GCE sensor platform has a stronger adsorption effect on Cu2+. It has high sensitivity (101.29 μA·μM−1) and a low detection limit (7.55 nM) in the linear range of 0.01 to 1.0 μM, as well as long-term stability, good repeatability and selectivity. The recovery rate was between 95.7 and 102.7% for real water samples. The method can be used for the trace analysis of Cu2+, which is valuable for the detection of trace metal ions in real water samples. [ABSTRACT FROM AUTHOR]

In this study, a label-free electrochemical aptasensor for sensitive detection of aflatoxin B1 (AFB1) was created by using a glassy carbon electrode (GCE) with polyaniline-functionalized graphene oxide (GO-PANI) and gold nanoparticles (AuNPs). Various spectroscopic techniques such as UV–Vis spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Zeta potential, and Raman spectra were employed to analyze the morphology and composition of the GO-PANI-Au nanocomposite, confirming its successful preparation. This aptasensor could be used for the detection of AFB1 with a broad linear range of 0.0001 to 50 ng/mL and a low limit of detection (LOD) of 0.0377 pg/mL under the optimized conditions. Furthermore, the constructed aptasensor displayed remarkable selectivity, repeatability, and stability. To validate the practical usability of our aptasensor, we successfully tested it on millet and corn samples, yielding a satisfactory recovery rate of 98.87–106.10% for AFB1 detection. This outcome highlights the potential application of our methodology in real sample analysis. A highly efficient and sensitive electrochemical aptamer sensor was successfully developed using GO-PANI-AuNPs nanocomposites, and can be used for the detection of AFB1 with good selectivity, repeatability, and stability. [ABSTRACT FROM AUTHOR]

This work aims at developing a customized ammoxidation catalyst through optimizing the metal oxide content in CrVO4/SiO2 catalysts. Various amounts of Cr–V–O with 1:1 molar ratio of Cr/V were successfully loaded on SiO2 via spray-drying method with colloidal silica as the binder. Polarized light microscope illustrated that the CrVO4/SiO2 particles presented as well dispersed microspheres in the microsize (20–80 μm). X-ray diffraction spectra confirmed the formation of monoclinic CrVO4 phase wherein the metal oxide content was ranged from 30 to 70 weight percent. FT-IR spectra indicated that the introduction of metal oxide had no obvious effects on the skeletal structure of SiO2. X-ray photoelectron spectroscopy analysis revealed that the valence state of V and Cr was hardly affected with increasing the metal oxide content. Performances of the obtained CrVO4/SiO2 catalysts with different metal oxide contents were investigated via the ammoxidation of a model compound, namely para-chlorotoluene (PCT) to para-chlorobenzonitrile (PCBN). A maximum conversion of 99.6% of PCT and 86.5% yield and 86.8% selectivity to PCBN have been obtained over the CrVO4/SiO2 catalyst with 60% weight of metal oxides at a temperature of 410 °C, n(PCT):n(NH3):n(air) = 1:3:15 and reaction load = 0.13 g/gCat·h. In addition, this catalyst was efficient and selective toward ammoxidation reactions of toluene, ortho- and meta-chlorotoluenes. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of anodic oxygen evolution reaction (OER) is regarded as the main bottleneck for ineffective hydrogen production efficiency, limiting the industrial application of electrochemical water splitting. Substituting the OER by urea electrooxidation reaction (UOR) and simultaneously developing highly active and economical bifunctional electrocatalyst for UOR and hydrogen evolution reaction (HER) is a promising method to realize energy-saving hydrogen production and urea-rich wastewater abatement. Herein, self-supporting Ni-NiO film grown on Ti mesh (Ni-NiO/TM) was successfully prepared by a facile cathodic electrodeposition method with using nickel acetate as the only raw material. Electrodeposition process was optimized by modulating the electrodeposition time and potential. x-ray diffraction, scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and Raman characterization revealed the optimized Ni-NiO/TM was comprised of crystalline Ni and amorphous NiO and its morphology exhibited nanosphere structure, assembled by nanosheets. Ni-NiO/TM sample prepared under the potential of −1.5 V and deposition time of 10 min illustrated the lowest UOR potential of 1.34 V at 50 mA cm−2 and robust stability, superior to the recently reported literatures. Furthermore, the HER potential was only −0.235 V to drive the current density of 50 mA cm−2. The cell voltage of urea-assisted electrolysis for hydrogen production in Ni-NiO/TM||Ni-NiO/TM two-electrode system only required 1.56 V to deliver 50 mA cm−2, obviously lower than that (>1.72 V) for overall water splitting. This work demonstrated the potential of Ni-based material as bifunctional electrocatalyst for energy-saving H2 production by urea-rich wastewater electrolysis. [ABSTRACT FROM AUTHOR]

The structural, surface, and upconversion (UC) luminescence properties of Y2O3:Ho3+,Yb3+ films grown by pulsed laser deposition, for different numbers of laser pulses, were studied. The crystallinity, surface, and UC luminescence properties of the thin films were found to be highly dependent on the number of laser pulses. The X-ray powder diffraction analysis revealed that Y2O3:Ho3+,Yb3+ films were formed in a cubic structure phase with an Ia 3 ¯ space group. The thicknesses of the films were estimated by using cross-sectional scanning electron microscopy, depth profiles using X-ray photoelectron spectroscopy (XPS), and the Swanepoel method. The high-resolution XPS was used to determine the chemical composition and oxidation states of the prepared films. The UC emissions were observed at 538, 550, 666, and 756 nm, assigned to the 5F4 → 5I8, 5S2 → 5I8, 5F5 → 5I8, and 5S2 → 5I7 transitions of the Ho3+ ions. The power dependence measurements confirmed the involvement of a two-photon process in the UC process. The color purity estimated from the Commission International de I'Eclairage coordinates confirmed strong green UC emission. The results suggested that the Y2O3:Ho3+,Yb3+ UC transparent films are good candidates for various applications, including solar cell applications. [ABSTRACT FROM AUTHOR]

This study outlines the design of a comprehensive chemical experiment to synthesize Ni-based nanocatalysts with varying grain sizes for biofuel production. Ni/CeO2、Ni/CeO2-SiO2 and Ni/SiO2 nanomaterials were prepared via a conventional impregnation method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The integrated scientific training process—from catalyst synthesis and structural characterization to performance evaluation—not only cultivate students’ comprehensive experimental skills, but also enhance their research literacy. This experiment aims to illuminate the intrinsic relationship between material structure and function, fostering a curiosity for investigating the unknown in the scientific realm. Moreover, the experiment incorporates a curricular focus on the “energy crisis”, heightening students’ awareness of current energy and environmental challenges, and inspiring a personal commitment to environmental stewardship. [ABSTRACT FROM AUTHOR]

In this work, aramid nanoparticles (ANPs) were prepared in dimethyl formamide (DMF) solution containing high impact polystyrene (HIPS) via a bottom-up approach. Transmission electron microscopy (TEM) images showed that the obtained ANPs were evenly distributed in the HIPS matrix without any agglomeration. Chemical composition of the ANPs, i.e., poly(p-phenyl-p-phenylenediamine) (PPTA), was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer (XRD). The ANP/HIPS composites, obtained after ethanol precipitation, were added to neat HIPS as fillers to fabricate ANP/HIPS composite sheets. The surface roughness and the glass transition temperature (Tg) of the sheets were characterized by atomic force microscope (AFM) and differential scanning calorimetry (DSC), respectively. Compared with neat HIPS, the mechanical properties of the composite sheet were significantly improved, and the Young's modulus increased from 246.55 MPa to 2025.12 MPa, the tensile strength increased from 3.07 MPa to 29.76 MPa, and the toughness increased from 0.32 N/mm2 to 3.92 N/mm2, with an increase rate of 721%, 869% and 1125%, respectively. Moreover, the thermal stability of the composites improved with the increase in ANP content. [ABSTRACT FROM AUTHOR]

Biochar has proven effective in the remediation of excess nitrogen from soil and water. Excess nitrogen from agricultural fields ends up in aquatic systems and leads to reduced water quality and the proliferation of invasive species. This study aimed to assess the efficiency of chemically surface-modified biochar produced from invasive Pistia stratiotes L. for the adsorption of inorganic nitrogen (NH4+ and NO3−). Biochar structure was investigated using scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and inductively coupled plasma mass spectrometry. The results from adsorption experiments indicate that NH4+ removal was optimal (0.8–1.3 mg N g−1) at near-neutral pH levels (6.0–7.5), while NO3− removal was optimal (0.4–0.8 mg N g−1) under acidic pH conditions (4.8–6.5) using the modified biochar. These findings highlight the significance of solution pH, biochar morphology, and surface chemistry in influencing the adsorption of NH4+ and NO3−. However, further studies are necessary to assess the potential oxidative transformation of NH4+ to NO3− by biochar, which might have contributed to the reduction in NH4+ in the aqueous phase. [ABSTRACT FROM AUTHOR]

Ultrasmall nanoparticles (diameter 2 nm) of silver, platinum, and bimetallic nanoparticles (molar ratio of Ag:Pt 0:100; 20:80; 50:50; 70:30; 100:0), stabilized by the thiolated ligand glutathione, were prepared and characterized by transmission electron microscopy, differential centrifugal sedimentation, X-ray photoelectron spectroscopy, small-angle X-ray scattering, X-ray powder diffraction, and NMR spectroscopy in aqueous dispersion. Gold nanoparticles of the same size were prepared as control. The particles were fluorescently labeled by conjugation of the dye AlexaFluor-647 via copper-catalyzed azide-alkyne cycloaddition after converting amine groups of glutathione into azide groups. All nanoparticles were well taken up by HeLa cells. The cytotoxicity was assessed with an MTT test on HeLa cells and minimal inhibitory concentration (MIC) tests on the bacteria Escherichia coli and Staphylococcus xylosus. Notably, bimetallic AgPt nanoparticles had a higher cytotoxicity against cells and bacteria than monometallic silver nanoparticles or a physical mixture of silver and platinum nanoparticles. However, the measured release of silver ions from monometallic and bimetallic silver nanoparticles in water was very low despite the ultrasmall size and the associated high specific surface area. This is probably due to the surface protection by a dense layer of thiolated ligand glutathione. Thus, the enhanced cytotoxicity of bimetallic AgPt nanoparticles is caused by the biological environment in cell culture media, together with a polarization of silver by platinum. [ABSTRACT FROM AUTHOR]

This study investigated the migration patterns of oxygen in the deoxidation process of Ti-48Al alloy scrap using electromagnetic levitation (EML) technology. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were employed to analyze the oxygen distribution patterns and migration path during EML. The refining process resulted in three types of oxygen migration: (1) escape from the lattice and evaporation in the form of AlO, Al2O; (2) formation of metal oxides and remaining in the alloy melt; (3) attachment to the quartz tube wall in the form of metal oxides such as Al2O3 and Cr2O3. The oxygen content of the scrap was dropped with a deoxidation ratio of 62%. It indicated that EML can greatly promote the migration and removal of oxygen elements in Ti-Al alloy scrap. [ABSTRACT FROM AUTHOR]

The hydroxyapatite and copper-doped hydroxyapatite coatings (Ca10−xCux(PO4)6(OH)2; xCu = 0, 0.03; HAp and 3CuHAp) were obtained by the vacuum deposition technique. Then, both coatings were analyzed by the X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and water contact angle techniques. Information regarding the in vitro antibacterial activity and biological evaluation were obtained. The XRD studies confirmed that the obtained thin films consist of a single phase associated with hydroxyapatite (HAp). The obtained 2D and 3D SEM images did not show cracks or other types of surface defects. The FTIR studies' results proved the presence of vibrational bands characteristic of the hydroxyapatite structure in the studied coating. Moreover, information regarding the HAp and 3CuHAp surface wettability was obtained by water contact angle measurements. The biocompatibility of the HAp and 3CuHAp coatings was evaluated using the HeLa and MG63 cell lines. The cytotoxicity evaluation of the coatings was performed by assessing the cell viability through the MTT assay after incubation with the HAp and 3CuHAp coatings for 24, 48, and 72 h. The results proved that the 3CuHAp coatings exhibited good biocompatible activity for all the tested intervals. The ability of Pseudomonas aeruginosa 27853 ATCC (P. aeruginosa) cells to adhere to and develop on the surface of the HAp and 3CuHAp coatings was investigated using AFM studies. The AFM studies revealed that the 3CuHAp coatings inhibited the formation of P. aeruginosa biofilms. The AFM data indicated that P. aeruginosa's attachment and development on the 3CuHAp coatings were significantly inhibited within the first 24 h. Both the 2D and 3D topographies showed a rapid decrease in attached bacterial cells over time, with a significant reduction observed after 72 h of exposure. Our studies suggest that 3CuHAp coatings could be suitable candidates for biomedical uses such as the development of new antimicrobial agents. [ABSTRACT FROM AUTHOR]

This study explores the effects of various temperatures on the surface modification of carbon fibers, as well as the effect of differing voltages and currents on the morphology, deposition rate, and thickness of the Ni plating layers. Post-treatment characterization of the samples was conducted utilizing scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) methods, thus facilitating a discussion on the mechanism of Ni plating. The findings demonstrate that at a temperature of 500 °C, the carbon fiber surface exhibits the highest concentration of functional groups, including hydroxyl (-OH), carboxyl (-COOH), and carbonyl (-C=O), resulting in the most efficacious modification. Specifically, exceeding 500 °C leads to significant carbon fiber mass loss, compromising the reinforcement effect. Under a stable voltage of 7.5 V, the Ni-plated layer on the carbon fibers appear smooth, fine, uniform, and complete. Conversely, at a voltage of 15 V, the instantaneous high voltage induces the continuous growth of Ni2+ ions along a singular deposition point, forming a spherical Ni-plated layer. In addition, a current of 0.6 A yields a comparatively uniform and dense carbon fiber coating. Nickel-plated layers on a carbon fiber surface with different morphologies have certain innovative significance for the structural design of composite reinforcements. [ABSTRACT FROM AUTHOR]