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In this report, we synthesized the neodymium-doped yttrium hydroxide nanobelts (Nd:Y(OH)3) using a facile route. The characterization methods, such as UV-Visible and photoluminescence spectroscopy, Raman, X-ray photoemission, Fourier transform infrared (FTIR) spectroscopy, and high resolution transmission electron microscopy (HRTEM), were applied to clarify the properties of the prepared colloidal sample. The structural characteristics of the prepared sample were analyzed via X-ray diffraction (XRD) and HRTEM. The average size of the hexagonal crystal is about 25 nm, which shows the compatibility of XRD and HRTEM spectroscopy results. Absorbance and emission spectra of the synthesized sample have demonstrated that the intensity of light emission by the colloidal sample is affected by the concentration of Nd3+ ions. In this research, it has been shown that the excitation of the samples with the wavelengths of 355 and 360 nm almost does not change the blue emission spectra because the wavelengths are related to the nature of the Nd+ 3, but with the excitation of 300 nm, the intensity of the emission spectra increases with the increase in the concentration up to 0.05 g (sample 2). [ABSTRACT FROM AUTHOR]

The rapid advancement of communication technology has led to an increase in electromagnetic interference (EMI), or electromagnetic (EM) pollution. This is a cause for concern, as EMI can disrupt communication services, damage electronic equipment, and pose health risks. Regulatory bodies are working to develop standards for the safe use of wireless devices, but the problem of EMI is likely to continue to grow as the number of Internet of Thing (IoT) devices continues to increase. To address this issue, this study investigated the effectiveness of carbon-coated cobalt ferrite nanoparticles as a potential material for electromagnetic shielding. The synthesis of cobalt ferrite (CoFe2O4) nanoparticles was successfully achieved using the co-precipitation method. Subsequently, a carbon coating was applied to the nanoparticles through a hydrothermal process using a 200mL autoclave made of te on-lined stainless steel. This process was carried out at a temperature of 180°C for a duration of 12 hours, with a heating rate of 8°C per minute. This study examined both uncoated and carbon-coated CoFe2O4 nanoparticles at various ratios of glucose to CoFe2O4 (1 : 1; 2 : 1, and 3 : 1) using techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and higher resolution transmission electron microscopy (HRTEM) analysis. The XRD analysis revealed distinct and well-defined peaks corresponding to CoFe2O4, indicating the successful synthesis of the nanoparticles. The crystallite size of the uncoated CoFe2O4 nanoparticles was measured to be 11.47 nm, while for the carbon-coated CoFe2O4, the average crystallite size was determined to be 14.15nm through XRD analysis. The results obtained from the FTIR analysis were consistent with previous reports and confirmed the formation of spinel CoFe2O4 nanoparticles, as suggested by published data. The morphological and structural properties of the prepared samples were further characterized using FESEM and HRTEM analysis, which demonstrated uniformity in both particle size distribution and morphology. Overall, the research findings indicated that the structure and properties of CoFe2O4 nanoparticles were significantly in uenced by the carbon coating process. Notably, the optimum ratio of carbon to CoFe2O4 was found to be 2 : 1, which resulted in the highest carbon thickness. The electromagnetic properties of the samples were evaluated using a vector network analyzer (VNA) and measured S-parameters in the frequency range of 8.2 to 12.4 GHz, known as the x-band region, suitable for radar applications. The sample with a carbon ratio of 2 : 1 exhibited the highest total shielding effectiveness (SE) of 17 dB at approximately 10 GHz. As a conclusion, the carbon- coated CoFe2O4 nanoparticles showed promising potential as an effective material for shielding against electromagnetic wave pollution, particularly when the carbon coating and filler composition reached an optimal point. Additionally, the shielding effectiveness performance of the sample could be further enhanced by incorporating a conductive polymer as an auxiliary material. [ABSTRACT FROM AUTHOR]

Metal hydroxides are extensively studied by researchers on account of the potential of these materials to be used in electrodes of energy storage devices. Remarkable electrochemical properties of nanostructured binary/ternary/quaternary metal hydroxides and their nanocomposites with carbonaceous materials prompted the investigation of these material groups for supercapacitor electrode applications. Zinc–aluminium binary hydroxide (ZAH) nanosheets and their nanocomposite with activated carbon (ZAH-AC) were synthesized by means of a hydrothermal method. X-Ray diffraction, selected area electron diffraction, Fourier transform infrared spectroscopy, and high resolution transmission electron microscopy were employed to study the basic characteristics of the synthesized samples. The electrochemical properties were studied using cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy using a three-electrode system. At 1 A g−1 current density, ZAH and ZAH-AC nanosheets achieved specific capacitances of ∼159 F g−1 and ∼573 F g−1, respectively. A two-electrode system was utilized to confirm the workability of ZAH-AC as an electrode material. This system exhibited a high capacitance retention of 152% after 2000 charge–discharge cycles. The addition of AC to ZAH led to the enhancement of the specific capacitance without any crystal structural alterations in ZAH. The synergistic effect of the charge storage mechanisms of AC and ZAH resulted in a highly stable electrode material with pseudocapacitive behaviour. [ABSTRACT FROM AUTHOR]

In this study, Boron Nitride Quantum Dots (BNQDs) are successfully synthesized via the hydrothermal method. Additionally, the hydrothermal method is employed to synthesize BNQDs decorated TiO2 nanograss (BNQDs/TiO2 NG) from BNQDs decorated TiO2 (BNQDs/TiO2). To validate the synthesis of different BNQDs samples, fluorescence spectroscopy (FL) is performed, revealing a strong quantum confinement effect resulting from variations in the precursor ratio. The bandgap energies of TiO2, BNQDs/TiO2, and BNQDs/TiO2 NG are determined using UV–Vis diffuse reflectance spectroscopy (UV-DRS), demonstrating a reduction in the band gap. A smaller band gap corresponds to a higher thermal conductivity, as there is a negative correlation between thermal conductivity and band gap energy. The study suggests that BNQDs/TiO2 NG exhibit higher thermal conductivity compared to TiO2 and BNQDs/TiO2. X-ray photoelectron spectroscopy (XPS) reveals the elemental composition of both BNQDs and TiO2, including Ti–O, B–N and B–O bonds. High Resolution Transmission Electron Microscopy (HR-TEM) is utilized to examine the morphological attributes of BNQDs/TiO2 NG. The crystalline structure of the synthesized composites is ascertained using X-ray diffraction (XRD). The photocatalytic degradation of methylene blue (MB) by TiO2, BNQDs/TiO2, and BNQDs/TiO2 NG under visible light is also compared. Based on the results, BNQDs/TiO2 NG is determined to be an effective material for treating wastewater containing organic dyes. [ABSTRACT FROM AUTHOR]

A series of La3+ ion doped magnesium nickel ferrites, Mg 0.5 Ni 0.5 Fe 2-x La x O 4 (0 ≤ x ≤ 0.1) having a cubic spinel structure were prepared by the co-precipitation method. Various characterization techniques, including X-ray diffractometer (XRD), high resolution transmission electron microscopy (HR-TEM), electron spin resonance (ESR) and vibrating sample magnetometer (VSM) were used to investigate structural and magnetic properties. The average crystallite size decreases and lattice parameter increases with La3+ ion doping and lie in the range of 12–7 nm and 8.347–8.361 Å respectively. Analysis of ESR spectra reveals that, g-value with La3+ ion addition decreases from 2.57 to 2.12. The saturation magnetization and the coercivity decrease with increasing rare-earth content. Magnetic-hysteresis (M − H) loop shifts from a ferromagnetic to a superparamagnetic nature with La3+ ion addition. The dielectric study was carried out in the frequency range of 1 KHz to 4000 KHz and temperature ranging 30 °C–350 °C using the impedance analyzer. The dielectric constant decreases with increasing frequency and the La3+ ion concentration. The dielectric loss of the sample increases with increasing temperature. The magnetic properties of the synthesized nanoparticles make them a potential material for stable ferrofluid application and the low tangent loss value makes these material a potential candidate for frequency-based applications. [ABSTRACT FROM AUTHOR]

In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime. [ABSTRACT FROM AUTHOR]

The water‐splitting reaction via electrocatalyst is a potential method for hydrogen evolution reaction (HER), and metal‐free electrocatalytic material with excellent performance are in great demand for future applications. In this context, a novel, facile, and efficient route for the synthesis of highly conjugated azomethine‐functionalized graphitic carbon nitride (GCN) is proposed. The GCN functionalized with azomethine moiety by using various proportions of GCN–x% dimethyl amino cinnamaldehyde (DMAC) (x = 0.1%, 0.5%, 1.0%, 5.0%, and 10.0%) of p‐DMAC leads to introduction of azomethine moiety onto the GCN matrix that does not affect the original framework of GCN network, but it efficiently enlarges its π‐delocalized system, increases its surface area, and enhances the electrocatalytic properties. All the structural and morphological properties of synthesized materials are analyzed by X‐ray diffraction, Fourier transform infrared, X‐ray photoelectron spectroscopy, Brunauer–Emmett–Teller, High resolution transmission electron microscopy, and field emission scanning electron microscopy, with Energy dispersive spectroscopy analysis. Furthermore, the GCN–5.0% DMAC exhibits superb HER performance with onset potential near to 0 V, and a low overpotential of 18.7 mV at 5 mA cm−2, and extremely ultrasmall Tafel slope (46.8 mV dec−1) in an 0.5 m H2SO4. In this study, the door is laid for interfacial engineering to be used as an efficient method for economically developing electrocatalysts. [ABSTRACT FROM AUTHOR]

Syngas produced by catalytic partial oxidation (CPOX) of propane contains hydrogen (21.68%) and carbon monoxide (18.27%). Microtubular solid fuel cells (μT-SOFCs) were fabricated and tested with syngas and pure hydrogen respectively. The open-circuit voltage (OCV) is 1.02 V, and the maximum power (MP) of microtubular solid fuel cell is 7.07 W at 700 °C with syngas/air. After operating in syngas/air for 100 h, the voltage declined 4.5%. A few sites of anode separate from electrolyte, particularly, some few nanometers nickel (Ni) particles have precipitated at the interface of electrolyte/anode. Comparing to Ni grain with 200 nm-1 μm diameter in rest sites of anode, it is easy to explain the loss of Ni and the separation of anode with electrolyte. Meantime obvious carbon deposition is found at the pores after 100 h working in syngas/air. There are other impurity phases discovered by high resolution transmission electron microscopy (HRTEM) at a triple phase boundary (TPB) of electrolyte and anode. • Nano-domains of nickel are expelled as clusters from anode into amorphous oxidized phase. • The loss of nickel causes to the difference of nickel grain size. • The structure of anode is destroyed by the growth of carbon at 700 °C. • The triple phase boundary degenerates towards the double phase boundary for long-term working. [ABSTRACT FROM AUTHOR]

Protonic Ceramic fuel cells (PCFCs) hold great promise for many applications; however, their high operating temperature hinders their commercial use in practice. The crucial issue that limits the electrochemical performance of PCFCs (including oxygen and proton-ion-conducting) is the sluggish oxygen redox reaction (ORR) at the cathode surface at low operating temperatures. Herein, we have developed a C aFe 2 O 4 -WO 3 heterostructure composite by interface-vacancy engineered for an efficient ORR electrocatalyst for LT-PCFCs. The C aFe 2 O 4 -WO 3 heterostructure composite exhibits very low cathodic area-specific resistance (ASR) and high oxygen reduction reaction (ORR) activity response at low operating temperatures of 400–550 °C using a BaCe 0.7 Zr 0.2 Y 0.1 O 3-δ (proton-conducting) electrolyte. We have demonstrated high-power density of 585 ± 2% mW-cm−2 with a current density of 1660 mA-cm−2 at 550 °C with H 2 fuel and atmospheric air as oxidant and even with possible operation at 400 °C. Moreover, the CaFe 2 O 4 -WO 3 heterostructure composite shows a very low proton migration energy and activation energy compared to individual CaFe 2 O 4 and WO 3 , helping to promote ORR activity. Various spectroscopic measurements, such as X-ray diffraction, high resolution transmission electron microscopy (HR-TEM), U-visible spectroscopy (UV–visible), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations are employed to understand the interfacial properties for the improved ORR electrocatalytic activity of the CaFe 2 O 4 -WO 3 heterostructure composite cathode. Our obtained experimental and theoretical results can further help to develop functional cobalt-free electrocatalysts for LT-PCFCs. [Display omitted] [ABSTRACT FROM AUTHOR]

The discovery of nanoparticles with varied size, shape and composition has stretched the limits of nanotechnology in almost any field. One of the important areas of interest is the use of nanoparticles in heterogeneous catalysis, whereby it offers an advantage by providing large surface area. Our present work focussed on the development of a graphene-based nanocatalyst (Pd@NGO) as an efficient tool to study various organic transformations. The prepared mesoporous catalyst was characterised by X-ray diffraction (PXRD), thermogravimetric analysis (TGA), field emission-scanning electron microscopy (FE-SEM), Brunauer–Emmett–Teller (BET), high resolution transmission electron microscopy (HR-TEM) and Fourier transformer infrared spectroscopy (FT-IR), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). TEM images showed the light grey sheets of N-GO on which Pd(0) nanoparticles were immobilised. BET analysis confirmed the mesoporous texture of the designed nanocatalyst by giving the surface area of 12.933 m2 g−1 with a pore volume and average pore diameter of 0.020685 cm3 g−1 and 6.39 nm, respectively. Also, FTIR data affirmed the presence of a characteristic C–N peak near 1271 cm−1 showing successful doping of nitrogen over graphene oxide. The XPS data revealed the presence of various elements like carbon (C 1s), nitrogen (N 1s), oxygen (O 1s) and Pd 3d. The prepared nanocatalyst was explored in Suzuki coupling reaction under green conditions, reduction of nitro compounds and the photodegradation of methyl orange with a degradation efficiency of 98.77%. The photodegradation of dyes is viewed as a potential method for the treatment of industrial wastewater due to its low cost, ecologically acceptable procedure, and lack of secondary contamination. Through direct photodegradation or a degradation process involving sensitization, this approach exhibits the light-enhanced creation of charge carriers and reactive radicals that non-selectively break down a variety of organic dyes into water, CO2, and other organic molecules. Moreover, Pd@NGO shows excellent stability and can be used multiple times, and hence possesses efficient reusability. [ABSTRACT FROM AUTHOR]

A key challenge encountered by printed electronics is that the conductivity of sintered metal nanoparticle (NP) traces is always several times smaller than the bulk metal conductivity. Identifying the relative roles of the voids and the residual polymers on NP surfaces in sintered NP traces, in determining such reduced conductivity, is essential. In this paper, we employ a combination of electron microscopy imaging and detailed simulations to quantify the relative roles of such voids and residual polymers in the conductivity of sintered traces of a commercial (Novacentrix) silver nanoparticle-based ink. High resolution transmission electron microscopy imaging revealed details of the morphology of the inks before and after being sintered at 150 °C. Prior to sintering, NPs were randomly close packed into aggregates with nanometer thick polymer layers in the interstices. The 2D porosity in the aggregates prior to sintering was near 20%. After heating at 150 °C, NPs sintered together into dense aggregates (nanoaggregates or NAgs) with sizes ranging from 100 to 500 nm and the 2D porosity decreased to near 10%. Within the NAgs, the NPs were mostly connected via sintered metal bridges, while the outer surfaces of the NAgs were coated with a nanometer thick layer of polymer. Motivated by these experimental results, we developed a computational model for calculating the effective conductivity of the ink deposit represented by a prototypical NAg consisting of NPs connected by metallic bonds and having a polymer layer on its outer surface placed in a surrounding medium. The calculations reveal that a NAg that is 35%–40% covered by a nanometer thick polymeric layer has a similar conductivity compared to prior experimental measurements. The findings also demonstrate that the conductivity is less influenced by the polymer layer thickness or the absolute value of the NAg dimensions. Most importantly, we are able to infer that the reduced value of the conductivity of the sintered traces is less dependent on the void fraction and is primarily attributed to the incomplete removal of the polymeric material even after sintering. [ABSTRACT FROM AUTHOR]

Geogenic arsenic has become a globally-distributed groundwater contaminant, liberated from the weathering of arsenic-bearing sulfide minerals and often transported to aquifer sediments adsorbed to iron oxides. Among the iron oxides, goethite (α-FeOOH) is uniquely important for the fate of arsenic because of its widespread abundance, stability, and high affinity for binding arsenic. Goethite is ubiquitous in soils and sediments and often contains substituted elements, including manganese. Structural manganese may affect the surface reactivity and redox capacity of goethite and alter the mechanisms of recrystallization catalyzed by dissolved Fe(II), potentially affecting arsenic adsorption. This study examined the fate of As(V) during the interactions between dissolved Fe(II) and Mn-substituted goethites at pH 4 and 7 as well as associated changes in arsenic speciation. At pH 7, the addition of dissolved Fe(II) initially increases the adsorption of As(V) onto Mn-bearing and Mn-free goethites. For the Mn-substituted goethites, the adsorbed As(V) slowly releases to solution at longer aging times. Fe(II) addition at pH 4 slightly increases As(V) uptake by Mn-substituted goethites, with differences in total sorption correlating with the Mn content in goethite. The addition of Fe(II) releases substantial dissolved manganese but the amount solubilized is higher at pH 4 compared to 7, suggesting that the presence of adsorbed As(V) may substantially promote the Mn release at pH 4. X-ray absorption fine structure spectroscopy shows that arsenic is stabilized as As(V) in all the samples and adsorbed on goethite via a bidentate binuclear mechanism. Fitting results show that the binding distance and coordination numbers are stable in Mn-free goethite and Mn-substituted goethite samples; the effect of substituted Mn on the surface complex structure is minor. High resolution transmission electron microscopy and X-ray diffraction confirm that no secondary ferrous arsenate minerals precipitate under both pH conditions. This study improves our understanding of the Fe(II)-As(V) interactions on iron oxides, and demonstrates that the substituted cations such as manganese may quantitatively alter the geochemical fate of arsenic during the reaction of dissolved Fe(II) with Fe(III) oxides. [ABSTRACT FROM AUTHOR]

For a long time, it was unclear how the myriads of microtubules are generated in a spindle to orchestrate cell division. In recent years, many microtubule nucleation pathways that generate spindle microtubules have been identified and shed light on this question. Moreover, the γ-tubulin ring complex (γ-TuRC), once thought to be the cell's sole nucleator, is now known to work synergistically with the protein XMAP215/ch-TOG. Recent high resolution cryogenic electron microscopy structures and in vitro single molecule studies of γ-TuRC provided clues towards its mode of action. It is an emerging concept that biomolecular condensation plays a role in microtubule nucleation in the spindle. The next challenge will be to determine how γ-TuRC is targeted to the right location in the spindle at the right time and subsequently turned on to generate the spindle framework. The cell orchestrates the dance of chromosome segregation with remarkable speed and fidelity. The mitotic spindle is built from scratch after interphase through microtubule (MT) nucleation, which is dependent on the γ-tubulin ring complex (γ-TuRC), the universal MT template. Although several MT nucleation pathways build the spindle framework, the question of when and how γ-TuRC is targeted to these nucleation sites in the spindle and subsequently activated remains an active area of investigation. Recent advances facilitated the discovery of new MT nucleation effectors and their mechanisms of action. In this review, we illuminate each spindle assembly pathway and subsequently consider how the pathways are merged to build a spindle. [ABSTRACT FROM AUTHOR]

Many researchers have shifted their interest towards eco‐friendly, cost effective, and environmental‐based metal oxide nanoparticles. Herein, Cu2O nanoparticles are synthesized via green method for water splitting application. The prepared materials are characterized structurally and morphologically by field emission‐scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), X‐ray photoelectron spectroscopy (XPS) Raman, and UV–visible spectroscopy. It is found that size and morphology depend strongly on OLE concentration and reaction time. The temperature increase leads to the formation of copper oxide (CuO) nanoparticles, which exhibit quantum confinement behavior and have an optical band gap that increases with decreasing size. Photoelectrochemical (PEC) tests of the coated graphite with Cu2O nanoparticles show a severe instability of Cu2O under irradiation due to the oxidation state that can easily change. For that, a protective overlayer of cuprous sulfide Cu2S is successfully grown on the top of Cu2O nanostructures to stabilize the photocathode. After Cu2S deposition, the measured photocurrent is significantly improved. Thus, this material is very promising for hydrogen generation by water splitting. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA) films impregnated with CdSe nanoparticles were evaluated for the effect of morphology (from spherical to rod-shaped) and concentration of CdSe, on the optical and mechanical properties. CdSe nanodots and nanorods were synthesized by a modified microemulsion method with hydrazine hydrate as the shape modulator. CdSe nanoparticles and PVA/CdSe films were characterized by high resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV–Vis spectroscopy and universal testing machine (UTM) analysis. The tensile strength and % elongation (at break) of PVA/CdSe films, increased from 32.8 MPa and 178 % (for CdSe nanorods) to 40.3 MPa and 259 % (for CdSe nanodots), respectively. The effect of loading of CdSe in PVA films, were evaluated at 0.1, 0.5, 1.0, 5.0 and 10 wt%. The tensile strength increased from 18.9 MPa (plain PVA) to 35.08 MPa (1 % CdSe) and increased upto 40 MPa for 10 % CdSe. The absorbance of PVA/CdSe films increased, while the reflectance and the transmittance decreased, with increasing wt% of CdSe in PVA films. The colour, density and water-vapour permeability of PVA/CdSe films, were also estimated. The biodegradability of PVA/CdSe films in soil was found to increase by 55 % as compared with PVA films. [ABSTRACT FROM AUTHOR]

Transition metal borides have great potential to be low-cost, high-performance catalysts for novel energies despite the synthesis is rather difficult. In this paper, the reduced graphene oxide (rGO) supported iron boride (Fe 2 B/rGO) based catalysts are synthesized by a facile reduction method. The successful synthesis of Fe 2 B is confirmed by X-ray diffraction, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photo-electron spectroscopy (XPS) and other tests. HRTEM tests showed that the constructed Fe 2 B was embedded in the rGO, where B played the role of coordination atoms which could regulate the electronic structure of the catalysts and improve the catalytic performance towards oxygen reduction reaction (ORR). The electrochemistry tests showed that the peak current intensity of the Fe 2 B/rGO catalyzed ORR could be reached up to 7.6 mA/cm2, which surpassed that of the Pt/C (20 wt%) catalyst. The current intensity can be kept at 82.47% after continuous running 20,000 s, which is higher than the Pt/C catalyst (79.4%). The onset potential reaches up to 0.95 V, which is only 0.06 V lower than that of Pt/C (20 wt%) catalyst. Both RDE and RRDE tests confirmed that the Fe 2 B/rGO catalyzed ORR major happed through 4-electron pathway. The redistributed electron between iron and boron atoms promoted the happening of ORR on Fe 2 B/rGO catalysts. The results of this work provide a novel way to develop high performance transition metal boride based catalysts for ORR. [Display omitted] • Fe 2 B based catalysts for ORR with the onset potential of 0.06 V was synthesized. • Peak current intensity of Fe 2 B/rGO catalyzed ORR was above that of Pt/C catalyst. • The reaction mechanism of iron-boride catalyzed ORR was illustrated. • Metal-boride materials have great potential to be high performance ORR catalysts. [ABSTRACT FROM AUTHOR]

This work studies the influence of the 2-hydroxyethylammonium acetate (2-HEAA) ionic liquid (IL) as an electrolyte in the electrochemical anodization of titanium for the synthesis of nanostructures for photoelectrochemical water splitting. Different 2-HEAA IL concentrations were used ranging from 0 to 4% v/v (IL-0 to IL-4) in electrolytes containing NH 4 F, water and ethylene glycol. Morphological, structural and electrochemical characterization of the nanostructures was carried out by means of field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and Mott-Schottky (MS) analysis. Additionally, photoelectrochemical tests were carried out in order to evaluate the efficiency of these materials as catalysts for water splitting applications. According to the obtained results, the electrolyte used for electrochemical anodization should contain little amount of NH 4 F (0.05 M) in order to obtain efficient nanostructures for photoelectrochemical purposes. However, small concentrations of IL (IL-0.25) resulted in nanostructures with higher photocurrents than doubling the NH 4 F concentration to 0.1 M. Therefore, the IL addition contributes to a more sustainable electrolyte formulation. The best photoelectrochemical response for water splitting processes was obtained for the nanostructures anodized with 1% v/v of 2-HEAA IL (IL-1) due to their high surface/area (higher pore diameters, smaller nanotubes wall thickness and higher nanotubes lengths), better crystallinity and electrochemical response, showing photocurrents more than 100% higher than the ones obtained for the nanotubes anodized without IL. [ABSTRACT FROM AUTHOR]

Metal halide-perovskite-quantum dots (MH-PQDs) have gained wide attention due to their tunable optoelectronic properties and better stability against the ambient environment compared to organometal halide-based PQDs. The stability of the perovskite QDs is of utmost importance, considering their application in light emitting diodes and photodetectors. Herein, we have systematically analyzed the stability of perovskite QDs and have fabricated a photodetector device by using the most stable Mn2+:CsPb(Br1−xClx)3 QDs. The manuscript discusses the synthesis of CsPbBr3 QDs and manganese (Mn) doped Mn2+:CsPb(Br1−xClx)3 QDs using the ligand-assisted re-precipitation (LARP) technique and have studied the correlation between various dopant concentrations and stability. Different concentrations of Mn2+ doping (0.7, 1, 1.5, and 3 mmol of MnCl2·4H2O) in CsPb(Br1−xClx)3 QDs were investigated to study the stability by aging and the optimum concentration of Mn2+ that could be doped into CsPb(Br1−xClx)3 QDs which offered better stability concerning its photoluminescence was found. The optical properties of the synthesized QDs were characterized using UV-Vis absorbance, photoluminescence (PL), and time resolved photoluminescence spectroscopy (TRPL) techniques. The formation of CsPbBr3 QDs with a size of 25.80 ± 3.69 nm and Mn2+:CsPb(Br1−xClx)3 QDs with a size of 22.65 ± 3.28 nm was confirmed by using the high resolution transmission electron microscopy (HR-TEM) technique. TRPL analysis revealed the d–d emission of the Mn2+:CsPb(Br1−xClx)3 QDs at 600 nm due to Mn2+ doping. Furthermore, the self-powered photodetector device was fabricated by using stable 0.7 mmol Mn2+-doped CsPb(Br1−xClx)3 QDs and achieved a quick response, such as a rise time (ton) of 438 ± 8 ms and fall time (toff) of 592 ± 11 ms under one sun illumination. This work could be useful in the field of optoelectronics, especially in the study of doped semiconductor QDs. [ABSTRACT FROM AUTHOR]

The present study was focused on green synthesis of Silver nanoparticles (AgNPs) using Trigonella foenum‐graceum L. seed extract belonging to specific variety HM (Hisar Mukta) 425, optimizing the different experimental conditions required for the formation and stability of AgNPs. UV‐Vis spectroscopy, Particle Size Analyzer (PSA), Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), X‐ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterise the synthesised AgNPs. The average size of AgNPs was found to be 22 nm and were spherical in shape. Additionally, the United States Environmental Protection Agency (USEPA) has listed nitrophenols as a priority pollutant, and biosynthesized AgNPs can catalytically convert them into less harmful aminophenols. One example of a reaction where AgNPs are used as a catalyst is the conversion of p‐nitrophenol to p‐aminophenol, which acts as a bridge for many analgesics and antipyretic medications. Hence, the study is anticipated to have a significant impact on the pharmaceutical, cosmetic, and food industries. [ABSTRACT FROM AUTHOR]

We have determined the proton, electrolyte (NaNO 3) and arsenate affinity constants on the corresponding surface sites of goethite. An empirical optimization approach was applied using the Charge Distribution Multisite Complexation (CD-MUSIC) model, initially, by simulating an extensive proton adsorption data set obtained from four goethites of specific surface areas (SSAs) spanning from 43 to 89 m2/g. Each goethite showed different crystal face compositions, which were measured previously from independent high resolution electron microscopy observations. Only the capacitance value was left as an additional optimizing parameter. For arsenate adsorption, with the above optimized values fixed, the contributing surface arsenate complexes and their respective affinity constants and charge distributions (CD) were also optimized. A unified set of affinity and CD parameters was obtained, where the only resulting variables among goethites were the capacitance 1, the specific surface area and the crystal face contributions (and thus their reactive surface site densities). It was found that the site density parameter is decisive when data show adsorption maxima, such as in the arsenate adsorption isotherms. The self-consistent modeling approach yielded pKa values of singly-coordinated sites of 8.82, and of triply-coordinated sites of 9.65. Three surface arsenate complexes bound only to singly-coordinated sites were found to describe all experimental data, although only two of them were predominant across the pH and As(V) concentration ranges investigated: a bidentate non protonated (BD) complex, and a protonated monodentate (HMD) one. Charge distribution of surface arsenate complexes was found to significantly influence the optimizations, but increased values of optimized capacitance 1 were found to compensate for previously underestimated surface site density values, to yield almost identical surface affinity and CD parameters. Finally, correlations found between surface site density and capacitance-1 parameters with SSA expanded the applicability of the modeling approach presented, to other goethites with different SSAs than the ones investigated here. [ABSTRACT FROM AUTHOR]

Aluminium doped zinc oxide (AZO) nanomaterials (AlxZn1-xO) with x fraction varying as 0.02 and 0.04 were synthesized using the auto-combustion method using glycine as a fuel. The synthesized catalysts were characterized with X-ray diffraction (XRD), UV–Visible Spectroscopy (UV–Vis), Raman spectroscopy, Photoluminescence (PL) spectroscopy, and High Resolution Transmission Electron Microscopy (HR-TEM). XRD results showed that synthesized materials possessed good crystallinity, while UV–VIS was employed to find the band gaps of synthesized materials. Raman was used to determine the vibrational modes in the synthesized nanoparticles, while TEM analysis was performed to study the morphology of the samples. Industrial effluents such as indigo carmine and azo carmine G were used to test the photodegradation ability of synthesised catalysts. Parameters such as the effect of catalyst loading, dye concentration and pH were studied. The reduction in crystallite size, band gap and increased lattice strain for the 4% AZO was the primary reason for the degradation in visible irradiation, degrading 97 and 99% equimolar concentrations of indigo carmine and azo carmine G in 140 min. The Al doped ZnO was found to be effective in faster degradation of dyes as compared to pure ZnO in presence of natural sunlight. [ABSTRACT FROM AUTHOR]

Liquid cell electron microscopy (LCEM) has long suffered from irreproducibility and its inability to confer high-quality images over a wide field of view. LCEM demands the encapsulation of the in-liquid sample between two ultrathin membranes (windows). In the vacuum environment of the electron microscope, the windows bulge, drastically reducing the achievable resolution and the usable viewing region. Herein, we introduce a shape-engineered nanofluidic cell architecture and an air-free drop-casting sample loading technique, which combined, provide robust bulgeless imaging conditions. We demonstrate the capabilities of our stationary approach through the study of in-liquid model samples and quantitative measurements of the liquid layer thickness. The presented LCEM method confers high throughput, lattice resolution across the complete viewing window, and sufficient contrast for the observation of unstained liposomes, paving the way to high-resolution movies of biospecimens in their near native environment. [ABSTRACT FROM AUTHOR]

Environmental remediation projects are becoming increasingly interested in polymers, transition‐metal oxides and graphene based nanocomposites as photocatalysts. To increase their effectiveness, they could be adjusted in conjunction with one another. A hierarchically organised nanocomposite of reduced graphene oxide based TiO2 and copolymer (Aniline and Indole) (rGO/ TiO2/P(ANI‐co‐IN)), TiO2/P(ANI‐co‐IN) and P(ANI‐co‐IN) has been synthesized by heterogeneous emulsion polymerization and is used as a catalyst for the degradation of the cationic Rhodamine (RhB) dye. Different analyses were used to characterize the resulting nanocomposites i. e. UV‐Vis diffuse reflectance spectra (DRS), Fourier Transform Infrared spectroscopy (FTIR), X‐ray diffraction (XRD), Energy Dispersive X‐Ray Spectroscopy (EDX), High Resolution Transmission electron microscopy (HR‐TEM), Selected area (electron) diffraction (SAED) and thermogravimetric analysis (TGA). DRS results revealed that the rGO/ TiO2/ P(ANI‐co‐IN) nanocomposites band gap decreased when compared to TiO2/P(ANI‐co‐IN) and P(ANI‐co‐IN). Here, rGO/ TiO2/P(ANI‐co‐IN) has outperformed every previous study on polymer/metal oxide/graphene‐based ternary nanocomposites, achieving 92 % RhB degradation within 80 min with a degradation rate constant of 0.032 min−1. The reusability of rGO/ TiO2/P(ANI‐co‐IN) was run over five cycles which bought in only a small change which could be negligible. Overall, this research may make it easier to synthesise hierarchically organised ternary nanocomposites in the future, which might be used to improve photocatalysis and address environmental protection challenges. [ABSTRACT FROM AUTHOR]

The performance of supercapacitors strongly depends on the electrochemical characterizations of electrode materials. Herein, a composite material consisted of iron(III) oxide (Fe2O3) and multilayer graphene-wrapped copper nanoparticles (Fe2O3/MLG-Cu NPs) is fabricated on a flexible carbon cloth (CC) substrate via two-step synthesis process for supercapacitor application. Where, MLG-Cu NPs are prepared on CC by one-step chemical vapor deposition synthesis approach; thereafter, the Fe2O3 is further deposited on the MLG-Cu NPs/CC via successive ionic layer adsorption and reaction method. The related material characterizations of Fe2O3/MLG-Cu NPs are well investigated by scanning electron microscopic, high resolution transmission electron microscopy), Raman spectrometer and X-ray photoelectron spectroscopy; the electrochemical behaviors of the pertinent electrodes are studied by cyclic voltammogram, galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy measurements. The flexible electrode with Fe2O3/MLG-Cu NPs composites exhibits the best specific capacitance of 1092.6 mF cm−2 at 1 A g−1, which is much higher than those of electrodes with Fe2O3 (863.7 mF cm−2), MLG-Cu NPs (257.4 mF cm−2), multilayer graphene hollow balls (MLGHBs, 14.4 mF cm−2) and Fe2O3/MLGHBs (287.2 mF cm−2). Fe2O3/MLG-Cu NPs electrode also exhibits an excellent GCD durability, and its capacitance remains 88% of its original value after 5000 cycles of the GCD process. Finally, a supercapacitor system consisted of four Fe2O3/MLG-Cu NPs/CC electrodes can efficiently power various light-emitting diodes (i.e. red, yellow, green, and blue lights), demonstrating the practical application of Fe2O3/MLG-Cu NPs/CC electrode. [ABSTRACT FROM AUTHOR]

In the present work, zinc sulphide (ZnS) nanoparticles are synthesized via solvothermal route using different capping agents. The sphalerite phase is detected by X-ray diffraction (XRD) analysis. The morphology of the nanoparticles is confirmed by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The average particle size is found between 5 and 7 nm as calculated by HRTEM analysis. Energy dispersive X-ray spectroscopy (EDX) specified the desired elemental composition. Bandgap studies are done by UV–visible absorption and the photoluminescence spectroscopy (PL) gives the emission peaks centered at 452 nm and 460 nm. Fourier transform infra-red spectroscopy (FTIR) of ZnS nanoparticles confirmed the presence of various functional groups and showed the encapsulation of capping agents. The cylindrical non-woven network of PAN-ZnS nanofibers synthesized by electrospinning technique as confirmed by SEM and the distribution of nanoparticles in the polymer matrix is confirmed by HRTEM analysis. EDX and FTIR showed the incorporation of ZnS nanoparticles in polymer matrix. The objective of the present work is to synthesize the PAN-ZnS composite nanofibers for antibacterial applications. To the best of our knowledge this type of studies using polyacrylonitrile (PAN) as a polymer are not found in the literature showing the novelty of our work. [ABSTRACT FROM AUTHOR]

With an aim to combine the catalytic properties of Pd nanoparticles (NPs) with the excellent characteristics of porous layered double hydroxides (LDH), in the present study, four different catalysts (Pd/Fe3O4‐CoTiMgAlLDH, Pd/Fe3O4‐CoTiMgLDH, Pd/Fe3O4‐CoTiAlLDH and Pd/Fe3O4‐CoTiLDH) were synthesized by supporting Pd NPs onto four different Fe3O4‐LDH supports, which were synthesized by varying the metals in LDH. The catalytic activity of these catalysts was studied for Suzuki coupling and reductive degradation of dyes. Pd/Fe3O4‐CoTiMgLDH outperformed the other catalysts in both reactions. The synthesized catalysts were examined via different characterization techniques like X‐ray diffraction (XRD), Brunauer–Emmett–Teller analysis (BET), X‐ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), high resolution transmission electron microscopy (HR‐TEM), field emission scanning electron microscopy (FE‐SEM), energy dispersive X‐ray (EDX), energy dispersive X‐ray mapping (SEM–EDX mapping), inductively coupled plasma atomic emission spectroscopy (ICP‐AES) and vibrating sample magnetometry (VSM). On the basis of results obtained from XPS and the experimental data, Fe3O4‐CoTiMgLDH was found to be the support of choice as it not only stabilized the Pd0 NPs but also increased the electron density on the anchored Pd0 species, which enhanced the catalytic activity of Pd/Fe3O4‐CoTiMgLDH for studied organic transformations. [ABSTRACT FROM AUTHOR]

Glass matrices of Li2B4O7 doped with Dy3+, Yb3+ and Cu were synthesized using copper concentration as the control parameter by melt quenching technique. The amorphous phase of lithium borate was corroborated by X-Ray diffraction (XRD) while size distribution of Nanoparticles was obtained by transmittance electron microscopy (TEM) and crystal phase of Cu nanoparticles was obtained by high resolution transmittance electron microscopy (HRTEM). For photoluminescence, characterizations used were absorbance, photoluminescence emission (PL) and experimental decay times (τexp); from the data obtained we performed Judd–Ofelt analysis where we calculated Judd–Ofelt parameters ( Ω i ), transition probabilities (A), branching ratios (β ) and decay times (τcalc). With absorbance and PL characterizations in conjunction with CIE 1931, efficiency and shift to white light emission were evaluated. The insights gained from this study have significant implications for future research focused on enhancing the photoluminescence properties of rare earth-doped systems. A comprehensive understanding of the underlying mechanisms behind these phenomena enables us to leverage plasmon effects in similar systems, leading to diverse applications such as color tuning emission. [ABSTRACT FROM AUTHOR]

A hydrothermal method was employed for green synthesis of fluorescent carbon dots (GCDs) from Annona squamosa leaves. The synthesized GCDs were confirmed by microscopic and spectroscopic techniques such as: High Resolution Transmission Electron Microscopy (HR-TEM), Atomic Force Microscopy (AFM), UV–Vis spectrometry, Fluorescence spectrometry, X-Photoelectron Spectroscopy (XPS), X-ray Diffraction spectroscopy (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). The produced GCDs had shown multiple properties, including massive antibacterial activity at concentration 200 μg/ml. The stabilization of human red blood cells served as a method to assess the anti-inflammatory activity. We also looked at how GCDs affected the angiogenesis process. The density of blood vessels was significantly decreased after treatment with GCDs, according to the results of the Chorio-Allantoic Membrane assay (p < 0.05). As per the study prepared GCDs from fallen leaves of Annona squamosa have multifunctional applications. [ABSTRACT FROM AUTHOR]

Microstructure evolution and mechanical properties of the aging treated AlN/AZ91 composites were systematically investigated by optical microscopy (OM), high resolution scanning electron microscopy (HRSEM) with an energy dispersive spectrum (EDS), and high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The results show that the higher fracture elongation (14 ± 1%) and ultimate tensile strength (275 ± 6 MPa) were simultaneously obtained in the peak-aged AlN/AZ91 composites. Comparied with AZ91 matrix alloy, the strength was increased by about 44% and the elongation was approximately five times higher, which mainly attributed to the precipitation of nano-sized γ-Mg 17 Al 12 phase and the activation of non-basal slip systems induced by in-situ AlN particles at room temperature. However, the in-situ formation of AlN reinforcements consumed part of Al element in the matrix alloy, which resulted into the volume fraction decreasing of γ-Mg 17 Al 12 precipitates, and then the age hardening and strengthening efficiency were reduced in the AlN/AZ91 composites. On the other hand, the mismatch of thermal expansion coefficient between AlN particles and AZ91 matrix generated high density dislocations around AlN particles, which promoted the precipitation of γ-Mg 17 Al 12 phase, and then the peak aging time and temperature were decreased. [ABSTRACT FROM AUTHOR]

This work presents the synthesis by the new ‘firing salts method’ (FSM) of orthorhombic Gd _2 TiO _5 which requires only two hours at 1200 °C. X Ray Diffraction, High Resolution Transmission Electron Microscopy, Fourier Transform Infrared Spectroscopy and Raman spectroscopy characterized it. Electron microscopy shows particle size distribution between 50–500 nm with orthorhombic structure according to Rietveld analysis. Raman—infrared spectroscopies and first principles calculations indicate that the second order contribution to the spectra comes from the Ti-O5 interactions. First principles calculations (Density Functional Theory) were used as an aid for the interpretation of the experimental results to assign the normal modes to the bands on the Raman and IR spectra; it also provided an insight of the chemical reactivity of the synthesis.

The missing-linker defects of UiO-66 were exploited to covalently anchor Cu nanoclusters (Cu/UiO-66). The molecular interactions between the metals and oxides as copper-zirconia interfaces in Cu/UiO-66 are essential for heterogeneous catalysis, leading to remarkable synergistic impacts on activity and selectivity. Homogeneously distributed carbonaceous mixed metal oxides (CuO/ZrO2@C) nanocomposite was prepared via carbonization of the Cu/UiO-66 at 600 °C for 3 h in air. To enhance the acidity properties of the CuO/ZrO2@C nanocomposite, a small amount of sulfuric acid was added and heated at 150 °C under an N2 atmosphere (CuO/ZrO2-SO3H@C). The synthesised Cu/UiO-66 and CuO/ZrO2-SO3H@C catalysts were used as novel catalysts in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The Cu/UiO-66 and CuO/ZrO2-SO3H@C catalysts displayed complete conversion of the 4-NP solution during (4 and 2 min) stirring at room temperature, respectively. These two catalysts exhibited a high reduction rate of 8.61 × 10–3 s−1, and 18.3 × 10–3 s−1, respectively. The X-ray photoelectron spectroscopic (XPS) analysis showed the charge of copper atoms in the Cu/UiO-66 catalyst was Cu0/CuII and in the CuO/ZrO2-SO3H@C catalyst was CuI/CuII with nearly the same ratio (65/35). The particle size and the elemental composition of the CuO/ZrO2-SO3H@C catalyst were analysed by using high resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS), and elemental mapping, respectively. The key point beyond the high catalytic activity and selectivity of the CuO/ZrO2-SO3H@C catalyst is both the carbon–metal oxides heterojunction structure that leads to good dispersion of the CuO and ZrO2 over the carbon sheets, and the high acidity properties that come from the combination between the Brønsted acid sites from sulfuric acid and Lewis acid sites from the UiO-66. The catalysts exhibited good recyclability efficiency without significant loss in activity, indicating their good potential for industrial applications. [ABSTRACT FROM AUTHOR]

The present work focuses on the photocatalytic degradation of methylene blue (MB) on erbium ion (Er3+) doped TiO2 under visible light. Pure TiO2 nanoparticles and erbium (Er3+) doped TiO2 nanocomposite (Er3+/TiO2) NCs were synthesized using the sol–gel method. The synthesized (Er3+/TiO2) NCs were characterized using Fourier transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HR-SEM), elementary dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectra (XPS), specific surface area (BET), zeta potential, and particle size. Different parameters were used to study their efficiency for the photoreactor (PR) and the synthesized catalyst. These parameters include pH of the feed solution, the rate of flow, the presence of an oxidizing agent (aeration pump), different ratios of nanoparticles, the amount of catalyst, and the concentrations of pollutants. An example of an organic contaminant was the dye methylene blue (MB). The result achieved using the synthesized nanoparticles (I) under ultraviolet light pure TiO2 was found to have degraded by 85%. For (Er3+/TiO2) NCs under visible light, dye removal increased with pH to a maximum of 77% degradation at pH 5. Furthermore, photocatalytic efficiency improves to 80% at 40 rpm (3 l/h) low motor speed. The degradation efficiency decreased to 70% when the MB concentration was increased from 5 to 30 mg/L. When oxygen content was increased using an air pump, and deterioration reached 85% under visible light, it improved performance. [ABSTRACT FROM AUTHOR]

Bismuth ferrite with manganese doping (BiFe0.95Mn0.05O3 or BFMO) and bismuth ferrite with cobalt and manganese doping (Bi0.95Co0.05Fe0.95Mn0.05O3 or BCoFMO) were both synthesized as nanocrystalline powders by the sol–gel autocombustion technique. X-ray diffraction examination of the powders indicates a rhombohedral distortion in the perovskite phase in both samples. The calcined powders were examined for their microstructure and elemental composition with high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDAX), respectively. Scanning electron microscopy (SEM) was used to examine the microstructures of sintered BMFO and BCoFMO specimens at room temperature. Dielectric characteristics were studied at various frequencies and temperatures and found to follow space charge polarization. At ambient temperature, a vibrating sample magnetometer was used to analyse the materials' magnetic behaviour (M–H loops). Saturation magnetization is significantly increased with increased coercivity in the BCoFMO sample compared to the other sample. Improved structural, dielectric, and magnetic values in these doped systems, however, suggest they'd be an excellent fit for spintronic, multifunctional memories, sensors, and actuators. [ABSTRACT FROM AUTHOR]

Lignin is expected to replace traditional fossil energy and convert it into a carbon material with excellent performance because of its advantages of being green and renewable, and its abundant reserves that are cheap and easy to obtain. The substitution of lignin for petroleum-based materials can not only effectively realize the high-value utilization of biomass, but reduce environmental pollution and energy loss. This work reported a simple and relatively low-temperature method to produce lignin-based graphene-like carbon materials. In this study, a lignin-based graphene-like film with micron thickness was successfully prepared by carbonization at a relatively low temperature (800 °C) using alkali lignin (AL) as a solid carbon source and large-area metal Ni sheets as catalyst. Through a series of characterization studies of the obtained products at different temperatures, the structural changes of AL and the growth process of the crystal nucleus are further explained. Moreover, the lattice fringes in few-layer graphene were observed by high resolution transmission electron microscopy, which showed that graphitic carbon structures are formed under the catalysis of metal Ni sheets. To sum up, the process was simple and low in energy consumption, and successfully converted biomass resource AL into high value-added carbon material products, alleviating the current problems of energy consumption and climate pollution. [ABSTRACT FROM AUTHOR]

The effect of vacancies on the evolution of strain-induced NbC precipitates (SIP) was studied in a model austenitic Fe–30Ni–0.1Nb-0.1C steel deformed at 925 °C. Precipitation growth and coarsening characteristics have been investigated in detail by employing high resolution transmission electron microscopy. In general, the SIP preferentially nucleated on the nodes of the periodic dislocation networks constituting microband walls and grew over the varying holding time following the conventional precipitation growth and coarsening theory. Nevertheless, the current results demonstrated unexpected sluggishness in the process of growth and coarsening of the precipitates on the introduction of intermediary population of vacancies by a quenching step added in the thermomechanical processing schedules. It has been suggested that the formation of stable vacancy-solute complexes may reduce the effective availability of solutes for the precipitate growth. [ABSTRACT FROM AUTHOR]

The structural properties of (x)CuO/(1-x)CdFe2O4 nanocomposites for x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 1.0 were studied. The X-ray diffraction (XRD) patterns confirmed the existence of both phases with a secondary phase of α-Fe2O3. The Fourier-transform infrared spectroscopy (FTIR) characterization showed the vibrational bands of the synthesized samples. The high resolution transmission electron microscopy (HRTEM) micrographs revealed the presence of CuO, CdFe2O4, and α-Fe2O3 phases and showed the polycrystalline nature of the prepared nanocomposites. The scanning electron microscope (SEM) study exhibited the morphology of the prepared nanostructures and indicated the agglomeration between them. The energy-dispersive X-ray spectroscopy (EDX) results revealed the presence of all chemical elements within the synthesized nanocomposites. Emission peaks of the samples were analyzed via Photoluminescence (PL) deconvolutions which approved the interface defects. The Mössbauer study showed the presence of hematite impurity and the results were coherent with XRD findings. The obtained M-H loops from the vibrating-sample magnetometer (VSM) analysis depicted a paramagnetic nature of CuO and showed the ferromagnetic behavior of the nanocomposites. [ABSTRACT FROM AUTHOR]

Creep strength in polycrystalline Ni-based superalloys is influenced by the formation of a rich variety of planar faults forming within the strengthening γ ′ phase. The lengthening and thickening rate of these faults – and therefore the creep rate – depends on an intriguing combination of dislocation interactions at the γ - γ ′ interface and diffusional processes of the alloying elements at the core of the fault tip. The effect of alloy composition on this process is not fully understood. In this work we use correlative high resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy to study the deformation faults in two different Ni-based superalloys with carefully designed ratios of disordering-to-ordering-promoting elements (Co-Cr against Nb-Ta-Ti). The results show that the additions of ordering-promoting elements reduce the diffusional processes required for the faults to lengthen and thicken thus reducing the creep rates found for the higher Nb-Ta-Ti alloy. These insights provide a path to follow in the design of improved grades of creep-resistant polycrystalline alloys beyond 700 ∘ C. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the ability of an aqueous leaf extract of Luisia tenuifolia to synthesize silver nanoparticles (AgNPs) and their antimicrobial and Aedes aegypti larvicidal activity. The presence of visible color changes ranging from pale yellow to dark brownish confirmed the presence of AgNPs in the reaction mixture. A sharp absorbance peak at 420 nm was found using a UV–visible spectrophotometer, confirming the presence of AgNPs. X-ray Diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR) analyses were used to investigate the crystalline structure and active functional groups involved in the reduction of AgNPs. The synthesized AgNPs were examined using High Resolution Transmission Electron Microscopy (HR-TEM), and it was discovered that the AgNPs were spherical in shape, with sizes ranging from 10 to 30 nm and a diameter of 0.241 nm. The crystalline structure of silver particles (face-centered cubic (fcc)) was confirmed by Selected Area Electron Diffraction (SAED) pattern analysis, which revealed concentric rings and blinking dots. At the highest concentrations (150 µg mL−1), the synthesized AgNPs have significant antimicrobial potential against some common bacterial pathogens such as Salmonella paratyphi (31 mm), Staphylococcus aureus (28 mm), Escherichia coli (20 mm), and Bacillus subtilis (23 mm), as well as phytopathogenic fungi such as Colletotrichum falcatum (12 mm), Fusarium sp. (12 mm), Aspergillus oryzae (10 mm), and Trichoderma sp. (10 mm) at the highest concentration (150 µg mL−1) of AgNPs. Fortunately, the synthesized AgNPs also have significant larvicidal potential against 1st and 2nd instar larvae of Ae. aegypti. Thus, aqueous leaf extract of Luisia tenuifolia synthesized AgNPs can be used to benefit humanity. [ABSTRACT FROM AUTHOR]

This research discloses a single step, facile, cost-effective, and eco-friendly fabrication of gold nanoparticles (AuNPs) using the aqueous extract of common reed (Phragmites australis) leaf. Various techniques were employed to characterize the resultant AuNPs such as UV–Vis spectroscopy, high resolution transmission electron microscopy (HRTEM) mapping, fourier transform infrared (FT-IR), Zeta potential, X-ray diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), and X-ray Photoelectron Spectroscopy (XPS) to confirm the bioformation of AuNPs. The results showed the formation of violet-colored, mainly spherical shaped AuNPs with about 18 nm diameter. The XRD results proved the crystalline structure of AuNPs. Furthermore, P. australis-AuNPs exhibited notable anticancer efficacy with an IC50 equals 129 μg/mL, good quenching for DPPH free radical with a scavenging percentage equals 10.26% and a superior photocatalytic activity as they completely removed methylene blue in just 1 min. The current study also provides an open option for the environmental management of the unwanted biomass of common reed. [ABSTRACT FROM AUTHOR]

In this research work, carbon dots (CDs) were synthesized from the renewable leaves of an indigenous medicinal plant by the one-pot sand bath method, Azadirachta indica. The synthesized CDs were characterized for its optical properties using UV–Vis, Fluorescence and Fourier transform infrared (FT-IR) spectrophotometry and for structural properties using dynamic light scattering (DLS), X-ray Diffraction (XRD) and high resolution Transmission electron microscopy (HR-TEM). The synthesized CDs exhibited concentration dependent biocompatibility when tested in mouse fibroblast L929 cell line. The EC50 values of biomedical studies, free radical scavenging activity (13.87 μgmL−1), and total antioxidant capacity (38 μgmL−1) proved CDs were exceptionally good. These CDs showed an appreciable zone of inhibition when examined on four bacterial (two gram-positive and gram-negative) and two fungal strains at minimum concentrations. Cellular internalisation studies performed on human breast cancer cells (MCF 7- bioimaging) revealed the applicability of CDs in bioimaging, wherein the inherent fluorescence of CDs were utilised. Thus, the CDs developed are potential as bioimaging, antioxidants and antimicrobial agents. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenide (TMDC) nanotubes complement the field of low‐dimensional materials with their quasi‐1D morphology and a wide set of intriguing properties. By introducing different transition metals into the crystal structure, their properties can be tailored for specific purpose and applications. Herein, the characterization and a subsequent preparation of single‐nanotube field emission devices of MoxWx‐1S2 nanotubes prepared via the chemical vapor transport reaction is presented. Energy‐dispersive X‐ray spectroscopy, Raman spectroscopy, and X‐ray diffraction indicate that the molybdenum and tungsten atoms are randomly distributed within the crystal structure and that the material is highly crystalline. High resolution transmission electron microscopy and electron diffraction (ED) patterns further corroborate these findings. A detailed analysis of the ED patterns from an eight‐layer nanotube reveal that the nanotubes grow in the 2H structure, with each shell consists of one bilayer. The work function of the nanotubes is comparable to that of pure MoS2 and lower of pure WS2 NTs, making them ideal candidates for field emission applications. Two devices with different geometrical setup are prepared and tested as field emitters, showing promising results for single nanotube field emission applications. [ABSTRACT FROM AUTHOR]

We report an efficient method to synthesize undoped and K-doped rare cubic tungsten trioxide nanowires through the thermal evaporation of WO3 powder without a catalyst. The WO3 nanowires are reproducible and stable with a low-cost growth process. The thermal evaporation processing was conducted in a three-zone horizontal tube furnace over a temperature range of 550–850 °C, where multiple substrates were placed at different temperature zones. The processing parameters, including pressure, temperature, type of gas, and flow rate, were varied and studied in terms of their influence on the morphology, aspect ratio and density of the nanowires. The morphologies of the products were observed with scanning electron microscopy. High resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction studies were conducted to further identify the chemical composition, crystal structure and growth direction of the nanostructures. Additionally, the growth mechanism has been proposed. Furthermore, we investigated the potassium doping effect on the physical properties of the nanostructures. Photoluminescence measurements show that there were shorter emission bands at 360 nm and 410 nm. Field emission measurements show that the doping effect significantly reduced the turn-on electric field and increased the enhancement factor. Furthermore, as compared with related previous research, the K-doped WO3 nanowires synthesized in this study exhibited excellent field emission properties, including a superior field enhancement factor and turn-on electric field. The study reveals the potential of WO3 nanowires in promising applications for sensors, field emitters and light-emitting diodes. [ABSTRACT FROM AUTHOR]

The objective of the study was carboxyl functionalization of Fe3O4 coated multiwalled carbon nanotubes (MWCNTs), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) / N-hydroxysuccinimide (NHS) mediated immobilization of Candida rugosa lipase on MWCNTs through rigid base of dopamine, flexible spacer ethyl methacrylate with adipic acid for improved enzyme characteristics including enhanced dispersion and separation; and use in production of flavour esters ethyl butyrate and butyl butyrate. The immobilized enzyme nanoparticles were characterised by using high resolution transmission electron microscopy (HRTEM), Fourier transmission infrared spectroscopy (FTIR), x-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), zeta potential analysis. Maximum protein loading of 133.83 mg g−1 support and immobilized enzyme activity 4,889.2 U g−1 support was obtained at the optimal time, pH, temperature, protein to support ratio. Immobilized enzyme was tested for pH, thermal, and storage stability. The esterification yields of ethyl butyrate 89.69% and butyl butyrate 91.07% were obtained under optimal conditions. The immobilized enzyme was separated from reaction mixture using the superparamagnetic property and reused for 11 cycles of esterification. Study showed the immobilized enzyme could be used for production of various fruit flavour esters. [ABSTRACT FROM AUTHOR]

Volume reconstruction from electron microscopy datasets is a tool increasingly used to study the ultrastructure of the synapse in the broader context of neuronal network and brain organization. Fine modifications of synapse structure, such as activity-dependent dendritic spine enlargement and changes in the size and shape of the postsynaptic density, occur upon maturation and plasticity. The lack of structural plasticity or the inability to stabilize potentiated synapses are associated with synaptic and neuronal functional impairment. Mapping these rearrangements with the high resolution of electron microscopy proved to be essential in order to establish precise correlations between the geometry of synapses and their functional states. In this review we discuss recent discoveries on the substructure of the postsynaptic compartment of central excitatory synapses and how those are correlated with functional states of the neuronal network. The added value of volume electron microscopy analyses with respect to conventional transmission electron microscopy studies is highlighted considering that some limitations of volume-based methods imposed several adjustments to describe the geometry of this synaptic compartment and new parameters-that are good indicators of synapses strength and activity-have been introduced. [ABSTRACT FROM AUTHOR]

The article presents the findings of the study that explores the ptychographic measurements of varying size and shape along zeolite channels. It mentions that porous materials like zeolites have received broad industrial applications that involve ion exchange, adsorption and separation, and catalysis.

The present work is performed on Pb2+ detection via electrochemical sensor. The novel aptasensor was developed by modification of glassy carbon electrode (GCE) with reduced graphene oxide (rGO) and gold nanoparticles (AuNPs) modified with ssDNA. The synthesized nanoparticles were characterized by HRTEM (high resolution transmission electron microscopy), SAED (selected area electron diffraction), UV–Vis spectrophotometer, FTIR, and XPS. The rGO was prepared by electrochemical reduction and thickness of rGO sheet was 0.5 to 1 nm. The average AuNPs size was 20–25 nm. The Pb2+ ion binds with specific ssDNA, and it will induce conformational changes of the aptamer and corresponding modulation of electrochemical signals. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for Pb2+ detection and optimization of sensor. The proposed aptasensor exhibits high sensitivity toward detection of Pb2+ ions with a detection limit of 1.52 nM and linear range of 5–50 nM at a signal-to-noise ratio of 3. Moreover, this aptasensor produces satisfactory results in environmental water samples analysis. The results of the newly developed aptasensor show better sensitivity and selectivity than the previously described electrochemical sensor. [ABSTRACT FROM AUTHOR]

We report the synthesis of novel quaternary AgInZn2Te4 quantum dots (QDs) utilizing organometallic hot injection procedures. By using octadecene and oleylamine as the coordinating solvents and dodecanethiol as the capping ligand, we could arrive at a phosphine-free "green route" for the synthesis. Detailed characterizations were performed using high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-optical emission spectroscopy (ICP-OES), energy dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy, and Photoluminescence (PL) spectroscopy for the structural, compositional, and optical analyses. The nanostructures were spherical, monodisperse, highly crystalline with cubic structure, and having an average diameter of 6. 5 ± 0. 5 nm with optical features in the visible region. [ABSTRACT FROM AUTHOR]

The growth of nanocrystals (NCs) from metal oxide-based substrates with exposed high-energy facets is of particular importance for many important applications, such as solar cells as photoanodes due to the high reactivity of these facets. The hydrothermal method remains a current trend for the synthesis of metal oxide nanostructures in general and titanium dioxide (TiO2) in particular since the calcination of the resulting powder after the completion of the hydrothermal method no longer requires a high temperature. This work aims to use a rapid hydrothermal method to synthesize numerous TiO2-NCs, namely, TiO2 nanosheets (TiO2-NSs), TiO2 nanorods (TiO2-NRs), and nanoparticles (TiO2-NPs). In these ideas, a simple non-aqueous one-pot solvothermal method was employed to prepare TiO2-NSs using tetrabutyl titanate Ti(OBu)4 as a precursor and hydrofluoric acid (HF) as a morphology control agent. Ti(OBu)4 alone was subjected to alcoholysis in ethanol, yielding only pure nanoparticles (TiO2-NPs). Subsequently, in this work, the hazardous chemical HF was replaced by sodium fluoride (NaF) as a means of controlling morphology to produce TiO2-NRs. The latter method was required for the growth of high purity brookite TiO2 NRs structure, the most difficult TiO2 polymorph to synthesize. The fabricated components are then morphologically evaluated using equipment, such as transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), electron diffraction (SAED), and X-ray diffraction (XRD). In the results, the TEM image of the developed NCs shows the presence of TiO2-NSs with an average side length of about 20–30 nm and a thickness of 5–7 nm. In addition, the image TEM shows TiO2-NRs with diameters between 10 and 20 nm and lengths between 80 and 100 nm, together with crystals of smaller size. The phase of the crystals is good, confirmed by XRD. The anatase structure, typical of TiO2-NS and TiO2-NPs, and the high-purity brookite-TiO2-NRs structure, were evident in the produced nanocrystals, according to XRD. SAED patterns confirm that the synthesis of high quality single crystalline TiO2-NSs and TiO2-NRs with the exposed {001} facets are the exposed facets, which have the upper and lower dominant facets, high reactivity, high surface energy, and high surface area. TiO2-NSs and TiO2-NRs could be grown, corresponding to about 80% and 85% of the {001} outer surface area in the nanocrystal, respectively. [ABSTRACT FROM AUTHOR]