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[Display omitted] • A novel core–shell Co 2 (PS 3)@Co 2 P is designed as a pre-catalyst. • The Co 2 (PS 3)@Co 2 P catalyst with fast surface reconstruction. • The PO 4 3−, SO 3 2− and SO 4 2−-decorated CoOOH as a true catalyst. • The oxyanions can enhance the activity and stability in seawater. • The oxyanions can optimize the intermediates' chemisorption. The design of pre-catalysts and the rational manipulation of corresponding electrochemical reconstruction are vitally important to construct the highly durable and active catalysts for seawater oxidation, but rather challenging. Herein, a novel core–shell catalyst of Co 2 (PS 3)@Co 2 P (labeled as CoPS) by epitaxial growth of amorphous cobalt phosphide (Co 2 P) on crystalline cobalt phosphorous trichalcogenide (Co 2 (PS 3)) is firstly designed as a pre-catalyst for alkaline seawater oxidation. Various characterization techniques are employed to demonstrate that the unique amorphous-crystalline nanowire structure (CoPS) achieves the rapid surface reconstruction into active CoOOH and diversiform oxyanions species (labeled as CoPS-R). Theoretical simulations uncover that the in situ derived oxyanions (PO 4 2−, SO 3 2− and SO 4 2−) on the surface of CoOOH can tune the electron distribution of Co site, thereby optimizing the chemisorption of oxygen evolution reaction (OER) intermediates on CoOOH and reducing the energy barrier of determining step. Consequently, in an alkaline natural seawater solution, the reconstructed CoPS-R catalyst exhibits small overpotentials of 357 and 402 mV for OER at 200 and 500 mA cm−2, respectively, together with an impressive durability over 500 h at a large current density of 500 mA cm−2 benefiting from the strong repulsive effect of the derived PO 4 2−, SO 3 2− and SO 4 2− oxyanions. This work offers a new insight for comprehending the relationship of structure-composition-activity and develops a new approach toward the construction of efficient and robust OER catalysts for seawater electrolysis. [ABSTRACT FROM AUTHOR]

This study explored mild and cost-effective conditions for the valorization of lignocellulosic biomass. Herein, reduced graphene oxide (rGO) supported magnetic core double-shell nanomaterials were successfully synthesized by an innovative four-step approach. Fe3O4 nanoparticles were first produced to act as cores without using any surfactants. The magnetite/silica core–shell structure was then prepared by hydrolysis of tetraethoxysilane in the presence of core particles under alkaline conditions. The outermost shell, the α-Fe2O3/TiO2 layer, was grown over a magnetic core of Fe3O4@SiO2 using a co-precipitation and calcination approach. Furthermore, nanohybrids were fabricated by loading Fe3O4@SiO2@α-Fe2O3/TiO2 nanoparticles on rGO using a hydrothermal method. Nanomaterial characterization by vibrating-sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) showed both nanomaterials with and without rGO support are soft ferromagnetic and the presence of Fe3O4, TiO2, Fe2O3 and SiO2 in both nanomaterials. The nanohybrids exhibited increasing photocurrent as a function of illumination by cool white fluorescent light, and their magnetic property enabled the particles to be magnetically separated for recycling and reuse. The efficient photoactivity of the Fe3O4@SiO2@α-Fe2O3/TiO2-rGO nanohybrids was confirmed for conversion of two lignocellulose model compounds: 83.9% for conversion of D-xylose, and production of 0.49 mol lactic acid for conversion of 1 kg of sodium lignosulfonate; these results represent an improvement compared to the core double-shell nanoparticle without rGO support. Increased productivities were also obtained for four other products in conversion of sodium lignosulfonate using the rGO-supported nanomaterials compared to the ones without rGO support. These findings indicate that the rGO support improved the properties of Fe3O4@SiO2@α-Fe2O3/TiO2, possibly by acting as an electron acceptor—thereby avoiding high recombination of electron–hole pairs and increasing the generation of hydroxyl radicals. Our primary results suggest that the approach exemplified by the produced photocatalysts may potentially lead to cost-effective and environment-friendly strategies for reducing lignocellulosic biomass and generating value-added chemicals in large scales. [ABSTRACT FROM AUTHOR]

A known property of quantum dots (QDs) is their characteristic luminescence, which would make it possible to detect different types of cancers after being functionalized with some type of biological molecule. For this reason, in the present investigation a methodological analysis of the physicochemical characteristics of the CdTe/ZnS core/shell QDs was carried out, using techniques such as Optical Absorbance Spectroscopy (UV–Vis), Molecular Fluorescence, Fourier Transform Infrared Spectroscopy (FT-IR), Dynamic Light Scattering (DLS), X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Zeta Potential that allowed to verify the photoluminescent effectiveness of these semiconductor nanocrystals as an alternative to conventional techniques currently used for the detection of specific cancers smaller than 1 cm. The study consisted of theoretically determining the bandgap energy, the size of the nanocrystals and the molar absorptivity from the wavelength value for the maximum intensity of the excitonic peak. It was also possible to verify the maximum intensity for each sample and thus evaluate its photoluminescent response, as well as it was possible to determine the charge distribution, the hydrodynamic size and the surface composition of each quantum dot. The results obtained correspond to what has been reported in the literature, which makes them good candidates for the detection of cancer in precancerous stages. [ABSTRACT FROM AUTHOR]

In this paper, a novel magnetic mesoporous Fe3O4@MCM-48@IL/Pd has been used as a reusable for the four-component microwave-assisted synthesis of benzo[a]furo[2,3-c] phenazine derivatives. The active nanocatalyst was obtained for the one-pot synthesis of various benzo[a]furo[2,3-c] phenazine derivatives in excellent efficiency in solvent-free conditions, which was characterized by excellent separation and recyclability. The size, surface charge, superparamagnetic properties, crystalline structure, and surface functional groups of nanoparticles were characterized and carried out utilizing several techniques such as X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDAX), Brunauer–Emmett–Teller (BET), value stream mapping (VSM), X-ray photoelectron spectroscopy (XPS), and TGA. The behavior of nanoparticle-modified glassy carbon electrodes (GCE) was studied by cyclic voltammetry (CV) techniques. The modified electrode has been successfully used for the determination of losartan (LOS) in real samples. The magnetic catalyst was used during six consecutive cycles without significant loss of activity in the degradation of rhodamine B under optimal conditions. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles (Fe3O4 NPs) have been intensively investigated because of their potential biomedical applications due to their high saturation magnetization. In this study, core–shell Fe3O4@C NPs (core = Fe3O4 NPs and shell = amorphous carbons, davg = 35.1 nm) were synthesized in an aqueous solution. Carbon coating terminated with hydrophilic –OH and –COOH groups imparted excellent biocompatibility and hydrophilicity to the NPs, making them suitable for biomedical applications. The Fe3O4@C NPs exhibited ideal relaxometric properties for T2 magnetic resonance imaging (MRI) contrast agents (i.e., high transverse and negligible longitudinal water proton spin relaxivities), making them exclusively induce only T2 relaxation. Their T2 MRI performance as contrast agents was confirmed in vivo by measuring T2 MR images in mice before and after intravenous injection. [ABSTRACT FROM AUTHOR]

A novel core/shell nanoferrite material has been developed for use in various potential applications. Rare-earth doped calcium-ferrite with the compositional formula CaFe 1.925 Sm 0.05 Gd 0.025 O 4 was prepared as a core using the citrate auto-combustion method before being coated with PVA as a polymeric shell. High crystalline and single-phase orthorhombic nanoparticles are confirmed by XR-D (X-ray diffraction). An estimate has been made for the mean size of the crystal structures by analyzing the broadening of XR-D lines within a range of 20 nanometers. HR-TEM (high-resolution tunnelling electron microscope) micrographs also showed that the particles had an orthorhombic shape with well-defined boundaries. EDX (energy-dispersive X-ray) and FT-IR were used to investigate the elemental constitution and the molecular structure of samples. The dielectric properties were discussed in the basics of interfacial polarization and Koop's model. The anti-ferromagnetic nature of the samples was identified by a VSM (vibrating sample magnetometer). The proposed composition was found to improve the electromagnetic absorption performance, which was confirmed with the measurements of optical parameters from the absorbance spectrum recorded by the UV–VIS–NIR spectroscope. The optical band-gap and Urbach energies of the synthesized samples have been investigated, in addition to the refractive index and the extinction coefficient. The Wemple-DiDomenico oscillator model was used to examine the dispersion energies. [ABSTRACT FROM AUTHOR]

A variety of core‐shell structure catalysts with different shell thicknesses were fabricated by hydrothermal coating. Multiple characterization technologies including XRD, SEM, N2 adsorption‐desorption, NH3‐TPD and IR were employed to explore the physicochemical properties of all the samples, demonstrating that the shell layer was successfully introduced on the exterior of the core. The results of hexane cracking disclosed that with the increase of shell thickness, olefins selectivities increased continuously accompanied by a minor decrease of hexane conversion. Only when controlling the shell thickness to 150 nm could manifest the best performance with light olefins yields of 51.1 %, much higher than those of 23.2 % on the core catalyst. On the other hand, the catalyst lifetime was greatly improved, which presented a decrease of only 2.8 % in hexane conversion, relative to 9.7 % on the core catalyst during the reaction period of 80 h. Above exciting phenomenon was attributed to the growth of protective shell outside the core, which passivated the external acid sites greatly, thus side reactions were inhibited dramatically. It is firmly believed that our work provided a novel reference for the production of light oil cracking catalyst in industry, which will make up for the shortage of olefins considerably. [ABSTRACT FROM AUTHOR]

Rotaviruses employ an intra-particle ribonucleic acid (RNA) synthesis mechanism, whereby the 11-segmented double-stranded RNA (dsRNA) genome is transcribed and replicated within the confines of a proteinaceous capsid. In this manner, the rotavirus RNA-dependent RNA polymerase (VP1) only functions while tethered to the inner core shell protein (VP2). Atomic models of VP1 inside of rotavirus double-layered particles show that it is bound beneath the VP2 layer, slightly off center from each icosahedral fivefold axis. The VP1-VP2 interaction interface exceeds 1,000 Ų in area and likely involves numerous amino acid side chain and backbone contacts. Here, we analyzed the existing structural data to predict residues of VP2 that could make regulatory contacts with VP1. To test which, if any, of these core shell sites alter the activity of the polymerase, we employed recombinant, mutant VP2 proteins (strain SA11) and an in vitro dsRNA synthesis assay. Our results showed that VP1 had significantly increased in vitro activity in the presence of four single-alanine VP2 mutants (K5A, T344A, E345A, and E365A) as compared with wild-type (WT) VP2, suggesting that altered core shell sites negatively regulate the polymerase. We also identified five alanine VP2 mutants (R4A/K5A/R6A, Q73A/L78A/E83A, K95A, L355A, and R332A/S333A) that supported significantly reduced in vitro VP1 activity, indicating that these core shell sites normally promote polymerase function. For these latter mutants, four of them (Q73A/L78A/E83A, K95A, L355A, and R332A/S333A) assembled into virus-like particles (VLPs) and retained their capacity to encapsidate VP1. Still, polymerases tethered within VLPs made with R332A/S333A VP2 were significantly reduced in their capacity to perform in vitro dsRNA synthesis as compared with those within WT VLPs. These results suggest that the lower VP1 activity in the presence of R332A/S333A VP2 is unlikely to be the result of defective core shell formation or reduced polymerase tethering. Instead, VP2 sites R332 and S333 may directly induce conformational changes in the polymerase, allowing it to mediate dsRNA synthesis. This study identified precise rotavirus core shell residues important for regulating intra-particle polymerase activity, thereby contributing mechanistic insights into a central step of the rotavirus lifecycle. IMPORTANCE Rotaviruses are important causes of severe gastroenteritis in young children. A characteristic feature of rotaviruses is that they copy ribonucleic acid (RNA) inside of the viral particle. In fact, the viral polymerase (VP1) only functions when it is connected to the viral inner core shell protein (VP2). Here, we employed a biochemical assay to identify which sites of VP2 are critical for regulating VP1 activity. Specifically, we engineered VP2 proteins to contain amino acid changes at structurally defined sites and assayed them for their capacity to support VP1 function in a test tube. Through this work, we were able to identify several VP2 residues that appeared to regulate the activity of the polymerase, positively and negatively. These results are important because they help explain how rotavirus synthesizes its RNA while inside of particles and they identify targets for the future rational design of drugs to prevent rotavirus disease. [ABSTRACT FROM AUTHOR]

CdS@ZnS core shell nanocomposites were prepared by a one-pot hydrothermal route. The morphology of the composite was tuned by simply changing the Zn2+ precursor concentration. To characterize the samples prepared, various techniques were employed, including XRD, FESEM, TEM, XPS and UV-vis DRS. The band gaps of CdS and ZnS were measured to be 2.26 and 3.32 eV, respectively. Compared with pure CdS, the CdS@ZnS samples exhibited a slight blue shift, which indicated an increased band gap of 2.29 eV. The CdS@ZnS core shell composites exhibited efficient photocatalytic performance for H2 generation under simulated sunlight illumination in contrast to pure CdS and ZnS. Additionally, an optimized H2 generation rate (14.44 mmol·h−1·g−1cat) was acquired at CdS@ZnS-2, which was approximately 4.6 times greater than that of pure CdS (3.12 mmol·h−1·g−1cat). Moreover, CdS@ZnS heterojunction also showed good photocatalytic stability. The process of charge separation over the photocatalysts was investigated using photoelectrochemical analysis. The findings indicate that the CdS@ZnS nanocomposite has efficient charge separation efficiency. The higher H2 generation activity and stability for CdS@ZnS photocatalysts can be attributed to the intimate interface in the CdS@ZnS core–shell structure, which promoted the light absorption intensity and photoinduced charge separation efficiency. It is expected that this study will offer valuable insights into the development of efficient core shell composite photocatalysts. [ABSTRACT FROM AUTHOR]

Ferrites were among the earliest types of microwave absorbers due to their high magnetic dissipation and low cost. Ferrites, on the other hand, have some disadvantages, such as a low natural resonance frequency (fr), a lack of dielectric loss, and a high density. We effectively generated (SrMnCoFe 10 O 19 /MnCoFe 2 O 4)/SiO 2 samples with hollow microfiber morphologies and most of the effective parameters suggested to overcome these disadvantages and increase the microwave dissipation properties of ferrites. Hard and soft SrMnCoFe 10 O 19 /MnCoFe 2 O 4 hollow microfibers were obtained using sol-gel and electrospinning technology. After heat treatment at 1050 °C for 3 h, the binary ferrites are formed. (Hard ferrite/soft ferrite)/SiO 2 core-shell structures were fabricated by the Stober process, so their microwave absorption performance is greatly influenced by the hard/soft mass ratio and SiO 2 thickness of the sample. The fabricated fibers were characterized by x-ray diffraction (XRD), vibrating sample magnetometer (VSM), field emission scanning electron microscopy (FESEM), FTIR spectroscopy, and vector network analyzer (VNA). The single-phase structure of all microfibers was determined by X-ray diffraction (XRD) analysis. The phase formation of the coated microfibers is also elaborated using Fourier transform infrared spectroscopy (FTIR) based on identified chemical bonds. According to the (FESEM) analysis results, the microfibers manufactured have a homogeneous core–shell structure. A vector network analyzer was used to investigate the samples' dielectric constants and microwave absorption properties between 12 and 18 GHz at room temperature. The results showed that when the mass ratio is hard/soft (8: 2) and the mass ratio of ferrite/SiO 2 (1:1), the maximum reflectance loss is −27 dB and the absorption bandwidth is 2 GHz. The magnetic saturation (Ms) was calculated at 43.44 emu/g and the calculated coercivity values (1163.07 Oe) confirm the hard ferrite/soft ferrite/SiO 2 core-shell structures. [Display omitted] [ABSTRACT FROM AUTHOR]

Amoxicillin (AMX) is an antibiotic frequently used for the treatment of bacterial disorders and respiratory problems in both humans and animals. This work aims to synthesize a molecularly imprinted superparamagnetic polymer (SP-MIP) with a core-shell structure for the selective detection of AMX in real samples. Magnetite superparamagnetic nanoparticles (SNP) were prepared by the polyol method, coated with silica, and functionalized with silane groups. The polymerization process was executed using the free-radical precipitation method. Thermogravimetric analysis (TGA) was used to evaluate the thermal stability of the synthesized materials. The results obtained from N2 adsorption and desorption analyses showed that the surface area of SP-MIP (19.8 m2/g) was higher than that of the non-molecularly imprinted superparamagnetic polymer (SP-NIP—9.24 m2/g). The optimized adsorption analysis showed that both SP-MIP and SP-NIP followed SIP-type behavior, with adsorption constant KS 0.01176, 1/n 1.73. The selectivity tests showed that SP-MIP is highly selective for AMX in the presence of other molecules. Finally, for the recovery analysis, the application of SP-MIP for determining AMX in samples of tap water, river water, and drugs using HPLC yielded a mean recovery value of 94.3%. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles (Fe3O4 NPs) have been intensively investigated because of their potential biomedical applications due to their high saturation magnetization. In this study, core–shell Fe3O4@C NPs (core = Fe3O4 NPs and shell = amorphous carbons, davg = 35.1 nm) were synthesized in an aqueous solution. Carbon coating terminated with hydrophilic –OH and –COOH groups imparted excellent biocompatibility and hydrophilicity to the NPs, making them suitable for biomedical applications. The Fe3O4@C NPs exhibited ideal relaxometric properties for T2 magnetic resonance imaging (MRI) contrast agents (i.e., high transverse and negligible longitudinal water proton spin relaxivities), making them exclusively induce only T2 relaxation. Their T2 MRI performance as contrast agents was confirmed in vivo by measuring T2 MR images in mice before and after intravenous injection.

Background: Protein Corona (PC) of nanoparticles is a structure which composed of one or more layers of proteins adsorbed on the surface of nanomaterials, and the formation of PC is a universal process of spontaneous randomness. We take advantage of the formation principle of the PC, developed a simple and efficient method for label protein to nanoparticles. Methods: The artificialed protein corona (APC) on the surface of nanoparticles was synthesized via the artificialed methods of desolvation aggregation and crosslinking with control. Results: The dosage of precipitator and the ratio of protein to magnetic nanoparticles (MNPs)(particle size: 3 nm) were optimized, and the core-shell nanoparticles with narrow particle size (particle size: 10 nm) distribution were obtained. The MNPs with APC were characterized by transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Additionally, a hemolysis test on prepared MNPs was conducted with APC. The presence of APC coating on the surface of MNPs showed an improving effect to reduce the cytotoxicity. Cellular toxicity of MNPs with APC was also investigated on HFF1 cell lines. And the cells survival in the presence of APC coated MNPs and display neither reduced metabolism nor cytostatic effect. The functional test of the MNPs with APC showed that proteins can be modified and labeled onto magnetic nanoparticles and retain their original activity. Conclusions: This marking method is gentle and effective. And the properties of the APC propose MNPs as a promising candidate for multifunctional biomedical applications.

In this study, nitrogen-doped nickel graphene core cells (N-NiGR) are synthesized using the thermal chemical vapor deposition method. The structural, morphological, and chemical composition properties of N-NiGR are investigated using X-ray diffractometry (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. N-NiGR has shown potential as a material that can assist charge carrier transportation in the photoactive a layer of planar hybrid solar cell (PHSC) owing to its high charge carrier mobility and stability with the solution process. Here, we investigated for the first time an enhancement of the solar cell efficiency (by up to a 2% increase) in PHSCs by incorporating the charge selective N-NiGR into the device's photoactive layer. Synthesized N-NiGR with different concentrations are incorporated into the active layer of the devices as charge transport material. The device structure of an ITO-coated glass/Hole transport layer/(PBT7+N-NiGR+SnS)/Electron transport layer/Cathode is fabricated and the maximum power conversion efficiency of the device was observed to be about 4.35%. [ABSTRACT FROM AUTHOR]

Corrosive and toxic solutions are normally employed to polish sapphire wafers, which easily cause environmental pollution. Applying green polishing techniques to obtain an ultrasmooth sapphire surface that is scratch-free and has low damage at high polishing efficiency is a great challenge. In this paper, novel diamond/SiO2 composite abrasives were successfully synthesized by a simplified sol-gel strategy. The prepared composite abrasives were used in the semi-fixed polishing technology of sapphire wafers, where the polishing slurry contains only deionized water and no other chemicals during the whole polishing process, effectively avoiding environmental pollution. The experimental results showed that diamond/SiO2 composite abrasives exhibited excellent polishing performance, along with a 27.2% decrease in surface roughness, and the material removal rate was increased by more than 8.8% compared with pure diamond. Furthermore, through characterizations of polished sapphire surfaces and wear debris, the chemical action mechanism of composite abrasives was investigated, which confirmed the solid-state reaction between the SiO2 shell and the sapphire surface. Finally, applying the elastic-plastic contact model revealed that the reduction of indentation depth and the synergistic effect of chemical corrosion and mechanical removal are the keys to improving polishing performance. [ABSTRACT FROM AUTHOR]

In the last decade, there has been significant interest in the use of supercapacitors with high power density and cycle stability in a wide range of applications. Graphene-based hybrid electrodes are considered a very promising option for supercapacitors owing to the synergistic effects they exhibit. In this study, we provide a novel and efficient method for synthesising a core-shell nanocomposite consisting of reduced graphene oxide (rGO) wrapped around nickel sulphide (Ni 3 S 2) using a one-step hydrothermal process. The resulting rGO@Ni 3 S 2 composite exhibits excellent performance as a supercapacitor electrode while also being cost-effective. As a promising supercapacitor electrode, a relatively high specific capacitance of 1052.5 Fg−1 at current density of 1 Ag−1 in 1 mol.L−1 KOH aqueous solution, along with good cycling stability (with a 94.5 % retention rate after 10,000 cycles) were demonstrated for the rGO@Ni 3 S 2 core shell composite electrode. In addition, excellent electrochemical performances were also demonstrated for the asymmetric supercapacitor (ASC) by using rGO@Ni 3 S 2 as the cathode and activated carbon, respectively. The fabricated ASC showed with a high energy density of 61.9 Whkg−1 at the power density of 585.7 W kg−1. Such high performance of rGO@Ni 3 S 2 core shell electrode can enrich the prospects for future practical applications in energy storage. [Display omitted] [ABSTRACT FROM AUTHOR]

• A heterostructured nanoarry of CoNiP nanosheets on Ni 2 P nanowire was prepared. • The heterostructure shows a high activity for water splitting in alkaline media. • The OER process will cause the conversion of CoNiP into NiCoOOH on surface. • The overpotential at 100 mA·cm−2 decreases by 76 mV in anodic polarization. • The surface reconstruction can offer more active sites to OER. Efficient water splitting remains a challenge to produce clean and pure H 2 in an industrial scale for the lack of high-performance cost-effective stable electrocatalysts of hydrogen and oxygen evolution (HER and OER). Surface engineering is a novel proposal to upgrade the electrocatalytic performances of HER and OER catalysts. Herein, a hierarchical architecture composed of carbon-supported CoNiP nanoplates (NPs) on Ni 2 P nanowire was constructed. The nanoarray of CoNiP@Ni 2 P heterostructure shows a high bifunctional activity of HER and OER. The overpotential is 46 mV required for HER at 10 mA·cm−2 and 292 mV for OER at 100 mA·cm−2 in 1 mol· L −1 KOH. In addition, the nanoarray of CoNiP@Ni 2 P heterostructure also shows a high stability for HER. The HER activity can be maintained at 11 mA·cm−2 without loss after 50 h cathode polarization at the overpotential of 100 mV, while the OER activity continuously increases from 26 to 64 mA·cm−2 at an overpotential of 400 mV after 50 h anode polarization. The enhancement of the oxygen evolution performance can be ascribed to the surface reconstruction of CoNiP/Ni 2 P heterostructure nanoarray, which can offer more active sites to OER. Density functional theory (DFT) reveals surface reconstruction can create an oxygen-rich surface in favor of intermediate adsorption, thus enabling a fast OER kinetics at the interface of NiCoOOH/Ni 2 P heterostructure. This work highlights surface reconstruction adaptability to design advanced catalysts of efficient water splitting for commercial H 2 production. [Display omitted] [ABSTRACT FROM AUTHOR]

CH x * oxidation is one of the most vital routes to alleviate the carbon deposition problem of CO 2 reforming of methane (DRM) reaction. Whereas, little experimental evidence has been observed on NiMo catalysts where the CH x * oxidation was dominant over its dissociation reaction. Herein, to experimentally unveil the CH x * oxidation route of NiMo catalysts, we design three catalysts with different particle sizes and structures. Among them, Mo/Niphy@SiO 2 core shell catalyst demonstrated the dominant CH x * oxidation route over its dissociation based on in-situ diffuse reflectance infrared Fourier transform spectroscopy experiments. This was attributed to the confinement effect of SiO 2 and the formation of Ni–Mo alloy, inhibiting the CH x * dissociation reaction. It exhibited relatively stable CH 4 and CO 2 conversions (77 % and 75 % respectively) within 180 h. By contrast, on Mo/Niphy catalyst which has a big Ni size, CH x * was mainly dissociated to C* and oxidized to CO which further underwent a disproportion reaction to produce CO 2 and C*, leading to the severe carbon deposition and unstable DRM performance. The strategy to unveil the dominant role of CH x * oxidation via design catalysts with different sizes and structures sheds light on the study of reaction mechanism of other reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

The reaction time, temperature, ratio of precursors, and concentration of sodium citrate are known as the main factors that affect the direct synthesis process of SiO2@Au based on the chemical reaction of HAuCl4 and sodium citrate. Hence, we investigated, in detail, and observed that these factors played a crucial role in determining the shape and size of synthesized nanoparticles. The significant enhancement of the SERS signal corresponding to the fabrication conditions is an existing challenge. Our study results show that the optimal reaction conditions for the fabrication of SiO2@Au are a 1:21 ratio of HAuCl4 to sodium citrate, with an initial concentration of sodium citrate of 4.2 mM, and a reaction time lasting longer than 6 h at a temperature of 80 °C. Under optimal conditions, our synthesis process result is SiO2@Au nanoparticles with a diameter of approximately 350 nm. In particular, the considerable enhancement of Raman intensities of SiO2@Au compared to SiO2 particles was examined. [ABSTRACT FROM AUTHOR]

CdS@ZnS core shell nanocomposites were prepared by a one-pot hydrothermal route. The morphology of the composite was tuned by simply changing the Zn2+ precursor concentration. To characterize the samples prepared, various techniques were employed, including XRD, FESEM, TEM, XPS and UV-vis DRS. The band gaps of CdS and ZnS were measured to be 2.26 and 3.32 eV, respectively. Compared with pure CdS, the CdS@ZnS samples exhibited a slight blue shift, which indicated an increased band gap of 2.29 eV. The CdS@ZnS core shell composites exhibited efficient photocatalytic performance for H2 generation under simulated sunlight illumination in contrast to pure CdS and ZnS. Additionally, an optimized H2 generation rate (14.44 mmol·h−1·g−1cat) was acquired at CdS@ZnS-2, which was approximately 4.6 times greater than that of pure CdS (3.12 mmol·h−1·g−1cat). Moreover, CdS@ZnS heterojunction also showed good photocatalytic stability. The process of charge separation over the photocatalysts was investigated using photoelectrochemical analysis. The findings indicate that the CdS@ZnS nanocomposite has efficient charge separation efficiency. The higher H2 generation activity and stability for CdS@ZnS photocatalysts can be attributed to the intimate interface in the CdS@ZnS core–shell structure, which promoted the light absorption intensity and photoinduced charge separation efficiency. It is expected that this study will offer valuable insights into the development of efficient core shell composite photocatalysts.

This study proposes an electromagnetic shielding material sprayed with silver-coated copper powder (core-shell powder). The shielding properties of the material are analyzed in details section. Cross-sectional observation and sheet resistance measurement were used to determine the thickness and electrical conductivity of the electromagnetic shielding layer, which was generated by spray-coating; this aided in confirming the uniformity of the coating film. The results indicate that the electromagnetic interference shielding effectiveness increases when the silver-coated copper paste (core-shell paste) is used as the coating material rather than the conventional aluminum base. The proposed material can be used in various frequency ranges owing to the excellent shielding effectiveness of the core-shell paste used in this study. Further investigations on the optimized spray-coating type of electromagnetic shielding material are required based on the composition of the core-shell paste and the thickness of the coating film. [ABSTRACT FROM AUTHOR]

In this paper, unique nanocomposites of Gold: Lithium Niobate (Au-LiNbO3) were synthesized for the first time utilizing pulse laser ablation in liquid method (PLAL). Q-switched neodymium-doped yttrium aluminum garnet (Nd: YAG) laser was used to prepare suspension at different laser fluence in water environment for LN and Au targets, then deposited at n-Type silicon substrates. XRD analysis used to define the structure nature of these films. Photoluminescence measurements exhibited distinct emissions peaks that decreased as the laser fluence escalated. The surface morphology was examined using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), while image j software was used to determine surface nature and particles size of Au-LiNbO3 thin films. It is found aggregation threshold decrease as laser fluence increases with zeta potential ranging about -16 to -12 mV. [ABSTRACT FROM AUTHOR]

Hybrid and novel Gold core Lithium niobate shell (Au@LiNbO3, Au@LN) nanoparticles were prepared for the first time by two steps of laser ablation in liquid at different laser fluences. X-ray diffraction, Raman scattering, UV–Visible spectrophotometer, and transmission electron microscope were used to investigate the structural and optical properties of the core–shell nanoparticles. The X-ray diffraction results show that the synthesized Au@LiNbO3 core–shell nanoparticles are polycrystalline in nature, with 2 J/cm2 being the highest crystallinity nanoparticles. Transmission electron microscope studies show the formation of core–shell morphology and the size of the core and shell thickness depends on the laser fluence. The optical absorption of nanocomposites showed the presence of a plasmon peak related to gold (Au) at 500 nm. The energy gap of Au@LiNbO3 increased from 3.5 to 3.8 eV as laser fluence increased. The presence of active phonons was revealed by Raman results. The current–voltage characteristics of Au@LiNbO3/Silicon (Si) heterojunction in the dark and illumination are studied as a function of laser fluence. The maximum responsivity and detectivity are 0.69 A/W and 6.5 × 1012 Jones at 380 nm, respectively, for Au@LiNbO3/p-Si isotype heterojunction photodetector fabricated at 1.3 J/cm2 laser fluence. The Energy band diagram of Au@LiNbO3 core–shell nanoparticles under illumination is constructed. [ABSTRACT FROM AUTHOR]

Here in, we report a new strategy to achieve a strong emission in the NIR region, especially in ∼802 nm, by introducing a core-shell structured UCNPs, denoted as NaYF 4 : 25%Yb3+, 0.5%Tm3+@NaYF 4 : x%Yb3+ (x = 0, 2, 5,15,100), offering a superior advantage for future biosensing-bioimaging application. Through the induction of specific Yb3+ ion concentrations (2 % and 5 %) into the shell, under 980 nm laser excitation, we noticed a selective reduction in emission peaks in the visible region with an intensified NIR (802 nm). To evaluate the results, the NIR/visible ratio was examined by increasing the Yb3+ dopant concentration in the shell, and the highest ratio was observed for NIR/red emission (NIR/646 nm) increasing from 38 (0%Yb3+). 62 (5%Yb3+) and 40.9 (15%Yb3+) indicate greater attenuation of the emission at 646 nm compared to 449 nm, and 473 nm. Decay time and power dependence analysis studied on the optimum nano crystals outcomes (NaYF 4 : 25%Yb3+,0.5%Tm3+@ NaYF 4 : x%Yb3+ (x = 0, 2, 5). The results highlighted a significant increase in decay time at the 3H 4 → 3H 6 state of Tm3+ ions in line with the enhancement of 802 nm emission. The power dependence analysis for the NIR (802 nm), the slope values obtained as 2.03 (core) to 1.68 (0%Yb), 2.01(2%Yb), 1.76 (5%Yb) and 1.97 (15%Yb), indicating the two-photon process is responsible upconversion process. These findings provide evidence that either decay time or power dependence studies align with the enhancement of 802 nm emission. [Display omitted] • Enhancement single band NIR emission via active-core/active shell structure. • Selective reduction emission in visible region. • Effect of Yb dopant concentration in shell for energy migration and surface passivation. • Significant increase in decay time at the 3H 4.→ 3H 6 state of Tm3+ ions with 2%Yb doped in shell [ABSTRACT FROM AUTHOR]

Amoxicillin (AMX) is an antibiotic frequently used for the treatment of bacterial disorders and respiratory problems in both humans and animals. This work aims to synthesize a molecularly imprinted superparamagnetic polymer (SP-MIP) with a core-shell structure for the selective detection of AMX in real samples. Magnetite superparamagnetic nanoparticles (SNP) were prepared by the polyol method, coated with silica, and functionalized with silane groups. The polymerization process was executed using the free-radical precipitation method. Thermogravimetric analysis (TGA) was used to evaluate the thermal stability of the synthesized materials. The results obtained from N2 adsorption and desorption analyses showed that the surface area of SP-MIP (19.8 m2/g) was higher than that of the non-molecularly imprinted superparamagnetic polymer (SP-NIP—9.24 m2/g). The optimized adsorption analysis showed that both SP-MIP and SP-NIP followed SIP-type behavior, with adsorption constant KS 0.01176, 1/n 1.73. The selectivity tests showed that SP-MIP is highly selective for AMX in the presence of other molecules. Finally, for the recovery analysis, the application of SP-MIP for determining AMX in samples of tap water, river water, and drugs using HPLC yielded a mean recovery value of 94.3%.

It would be helpful to achieve appropriate synthetic routes to attain larger-scale production at industrial levels of nanocomposites at low costs. In the present work, diphasic composites with core–shell nanostructures formed by La2Fe2O6/CoFe2O4 are investigated. The core–shell structure is fabricated via different preparation methods. The advantages and the demerits of the synthesis techniques are discussed. The presence of both the spinel CoFe2O4 nano ferrite and orthorhombic La2Fe2O6 perovskite phases is revealed by X-ray diffraction. XPS spectroscopy is utilized to investigate the chemical composition of the prepared samples. The hysteresis loops of the prepared samples exhibit a smooth loop that is resulted from the existence of two homogeneous magnetic phases. For the first time, it has been found that the preparation conditions have the advantage of reducing the switching field distribution value for the core–shell nanoparticles. Exchange coupled core–shell nanoparticles present a high potential to regulate the magnetic properties for numerous applications such as heavy metal removal and/or data storage devices. The maximum adsorption capacity (qm) of Cr III on the core–shell (S3) is higher compared to other adsorbents previously testified in the literature. The cost-effective and eco-friendly prepared core–shell samples with good metal removal capacity have great potential for commercialization. [ABSTRACT FROM AUTHOR]

Capacitive deionisation (CDI) of saltwater, with the advantages of low energy consumption and being environmentally friendly, has been considered a potential solution to the scarcity of fresh water from sea, contaminated or waste waters. In the present work, Ag@C core-shell nanoparticle dispersed rGO (Ag@C/rGO) electrodes were synthesised and used for the CDI of saltwater. To better understand the formation mechanism of the Ag@C core-shell nanoparticles, temperature-programmed carbonisation of the Ag+-β-cyclodextrin complexes was studied by in situ synchrotron small-angle X-ray scattering spectroscopy. At 573 K, the core Ag metal forms Ag@C core-shell nanoparticles with the highest probability nanosizes of 40-80 nm. In the 4-cycle flow-by CDI (once through) experiments using the Ag@C/GO electrodes, high electrosorption efficiencies (25.0-44.9%) were obtained. Each CDI cycle involving electrosorption at 1.2 V and regeneration at 0 V for 1 h was highly reversible. In addition, the disinfection efficiency of the Ag@C/rGO electrodes, contributed by both silver and rGO, was very high (>97%). This study shows that the easily synthesised Ag@C/rGO core-shell carbon-based electrodes are feasible for simultaneous deionisation and disinfection of saltwater as a potential source of drinking water. [ABSTRACT FROM AUTHOR]

Corrosive and toxic solutions are normally employed to polish sapphire wafers, which easily cause environmental pollution. Applying green polishing techniques to obtain an ultrasmooth sapphire surface that is scratch-free and has low damage at high polishing efficiency is a great challenge. In this paper, novel diamond/SiO2 composite abrasives were successfully synthesized by a simplified sol-gel strategy. The prepared composite abrasives were used in the semi-fixed polishing technology of sapphire wafers, where the polishing slurry contains only deionized water and no other chemicals during the whole polishing process, effectively avoiding environmental pollution. The experimental results showed that diamond/SiO2 composite abrasives exhibited excellent polishing performance, along with a 27.2% decrease in surface roughness, and the material removal rate was increased by more than 8.8% compared with pure diamond. Furthermore, through characterizations of polished sapphire surfaces and wear debris, the chemical action mechanism of composite abrasives was investigated, which confirmed the solid-state reaction between the SiO2 shell and the sapphire surface. Finally, applying the elastic-plastic contact model revealed that the reduction of indentation depth and the synergistic effect of chemical corrosion and mechanical removal are the keys to improving polishing performance.

In this study, nitrogen-doped nickel graphene core cells (N-NiGR) are synthesized using the thermal chemical vapor deposition method. The structural, morphological, and chemical composition properties of N-NiGR are investigated using X-ray diffractometry (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. N-NiGR has shown potential as a material that can assist charge carrier transportation in the photoactive a layer of planar hybrid solar cell (PHSC) owing to its high charge carrier mobility and stability with the solution process. Here, we investigated for the first time an enhancement of the solar cell efficiency (by up to a 2% increase) in PHSCs by incorporating the charge selective N-NiGR into the device’s photoactive layer. Synthesized N-NiGR with different concentrations are incorporated into the active layer of the devices as charge transport material. The device structure of an ITO-coated glass/Hole transport layer/(PBT7+N-NiGR+SnS)/Electron transport layer/Cathode is fabricated and the maximum power conversion efficiency of the device was observed to be about 4.35%.

The reaction time, temperature, ratio of precursors, and concentration of sodium citrate are known as the main factors that affect the direct synthesis process of SiO2@Au based on the chemical reaction of HAuCl4 and sodium citrate. Hence, we investigated, in detail, and observed that these factors played a crucial role in determining the shape and size of synthesized nanoparticles. The significant enhancement of the SERS signal corresponding to the fabrication conditions is an existing challenge. Our study results show that the optimal reaction conditions for the fabrication of SiO2@Au are a 1:21 ratio of HAuCl4 to sodium citrate, with an initial concentration of sodium citrate of 4.2 mM, and a reaction time lasting longer than 6 h at a temperature of 80 °C. Under optimal conditions, our synthesis process result is SiO2@Au nanoparticles with a diameter of approximately 350 nm. In particular, the considerable enhancement of Raman intensities of SiO2@Au compared to SiO2 particles was examined.

Measuring the levels of the biomarkers vanillylmandelic acid (VMA) and 5-Hydroxyindole-3-acetic acid (5-HIAA) is a valuable tool for clinical diagnosis not only of neuroblastoma or carcinoid syndrome, but also of essential hypertension, depression, migraine, and Tourette's syndrome. Herein, we explore using graphene quantum dots (GQDs) coated with molecularly imprinted polymer (MIP) as novel dual-imprinted sensors for selective and simultaneous determination of VMA and 5-HIAA in urine and plasma samples. The dual-MIP was successfully coated on the GQDs core via co-polymerization of (3-aminopropyl) triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS), acting as functional and cross-linking monomers, respectively. In addition, we successfully created the dual imprinted VMA and 5-HIAA shell on the GQDs' core via a one-pot synthesis. We fabricated a facile and ready-to-use Origami three-dimensional electrochemical paper-based analytical device (Origami 3D-ePAD) for simultaneous determination of VMA and 5-HIAA using a GQDs@dual-MIP modified graphene electrode (GQDs@dual-MIP/SPGE). The Origami 3D-ePAD was designed to form a voltammetric cell on a three-layer foldable sheet with several advantages. For example, they were quickly assembled and enhanced the device's physical durability with the hydrophobic backup sheet. The developed dual imprinted Origami 3D-ePAD leads to substantially enhanced sensitivity and selectivity to electrochemical signal amplification generated from increasing the electrode-specific surface area, electrocatalytic activity, and the large numbers of dual imprinted sites for VMA and 5-HIAA detection. The synthetic recognition sites are highly selective for 5-HIAA and VMA molecules with an imprinting factor of 8.46 and 7.10, respectively. Quantitative analysis relying on square wave voltammetry reveals excellent linear dynamic ranges of around 0.001–25 μM, with detection limits of 0.023 nM for 5-HIAA and 0.047 nM for VMA (3S b , n = 3). The Origami 3D-ePAD provides high accuracy and precision (i.e., recovery values of 5-HIAA ranged from 82.98 to 98.40 %, and VMA ranged from 83.28 to 104.39 %), and RSD less than 4.37 %) in urine and plasma samples without any evidence of interference. Hence, it is well suited as a facile and ready-to-use disposable device for point-of-care testing. It is straightforward, cost-effective, reproducible, and stable. Furthermore, it allows for rapid analysis (analysis time ∼20s) useful in medical diagnosis and other relevant fields. [Display omitted] • One-pot synthesis for dual-imprinted sensor of VMA and 5-HIAA was firstly reported. • The sensor was fabricated on an Origami 3D-ePAD. • The sensor possesses good performance for simultaneous determination of 5-HIAA and VMA in urine and plasma samples. • The sensor is simple, ready-to-use, cost-effective, mechanically stable, and suitable for large-scale manufacturing. [ABSTRACT FROM AUTHOR]

This study proposes an electromagnetic shielding material sprayed with silver-coated copper powder (core-shell powder). The shielding properties of the material are analyzed in details section. Cross-sectional observation and sheet resistance measurement were used to determine the thickness and electrical conductivity of the electromagnetic shielding layer, which was generated by spray-coating; this aided in confirming the uniformity of the coating film. The results indicate that the electromagnetic interference shielding effectiveness increases when the silver-coated copper paste (core-shell paste) is used as the coating material rather than the conventional aluminum base. The proposed material can be used in various frequency ranges owing to the excellent shielding effectiveness of the core-shell paste used in this study. Further investigations on the optimized spray-coating type of electromagnetic shielding material are required based on the composition of the core-shell paste and the thickness of the coating film.

This study focuses on the synthesis, characterization, and evaluation of the performance of core shell nanostructure adsorbent for hydrogen sulfide (H2S) capture. Commercial coconut shell activated carbon (CAC) and commercial mixed gas of 5000 ppm H2S balanced N2 were used. With different preparation techniques, the CAC was modified by core shell impregnation with zinc oxide (ZnO), titanium oxide (TiO2), potassium hydroxide (KOH), and zinc acetate (ZnAC2). The core structure was prepared with CAC impregnated by single chemical and double chemical labelled with ZnAC2-CAC (single chemical), ZnAC2/KOH-CAC, ZnAC2/ZnO-CAC, and ZnAC2/TiO2-CAC. Then, the prepared core was layered either with KOH, TiO2, NH3, or TEOS for the shell. The synthesized adsorbents were characterized in physical and chemical characterization through scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) analyzers. Operation of the adsorber column takes place at ambient temperature, with absolute pressure at 1.5 bar. The H2S gas was fed into the column at 5.5 L/min and the loaded adsorbents were 150 g. The performance of synthesized adsorbent was analyzed through the adsorbent’s capability in capturing H2S gas. Based on the results, ZnAc2/ZnO/CAC_WOS shows a better adsorption capacity with 1.17 mg H2S/g and a 53% increment compared to raw CAC. However, the degradation of the adsorbents was higher compared to ZnAc2/ZnO/CAC_OS and to ZnAc2/ZnO/CAC_WS ZnAc2/ZnO/CAC_OS. The presence of silica as a shell has potentially increased the adsorbent’s stability in several cycles of adsorption-desorption.

In this work, we report core-shell heterojunction of Sm3+ ions doped ZnO nanoparticles (NPs) by green synthesis technique and their photocatalytic activity for rapid degradation of methyl green dye molecules under UV light irradiation. High-resolution X-ray diffraction and high-resolution transmission electron microscope characterization techniques were employed to investigate structural and morphological studies. It is found that, the crystallite size of NPs is decreased with increasing Sm3+ ions concentration in NPs since Sm3+ ions are inhibiting the further growth of NPs. In addition, Sm3+: ZnO NPs catalyst shows irregular core shell heterojunction ensuing in the augmentation of a charge partition. Following that, the elemental compositional studies of Sm3+: ZnO NPs were estimated by energy dispersive spectroscopy. XPS imaging is also done in this work to get chemical mapping and the results suggested that the peaks are related to the Sm3+ ions in the ZnO lattice, which confirms the appropriate incorporation of Sm3+ into the ZnO. The optical energy band gap of NPs was estimated using diffuse reflectance spectroscopy. Excitation spectrum of Sm3+: ZnO NPs tinted the typical f-f transitions of Sm3+ ions. Photoluminescence emission shows the e− /h+ pair recombination rate reduced with increasing wt% of dopant Sm3+ ions in NPs. 10 wt% Sm3+: ZnO NPs showed the optimum photodegradation efficiency towards methyl green dye under the irradiation of UV light for 50 min. The dye degradation rate of Sm3+: ZnO NPs was 91% which is 26% higher than that of pristine ZnO NPs. Furthermore, the catalyst retains its original efficiency after fifth cycle. [Display omitted] • ZnO NPs have successfully doped with Sm3+ ions by green synthesis process for photocatalytic applications. • HR-TEM characterization revealed the formation of core-shell (Sm 2 O 3 /ZnO) heterostructure in Sm3+ ions doped ZnO NPs. • The highest methyl green dye degradation rate of Sm3+ ions doped ZnO NPs was 91% in 50 min under UV light irradiation. • Green synthesized Sm3+ ions doped ZnO NPs could be anticipated as an excellent promising photocatalytic application. [ABSTRACT FROM AUTHOR]