Preparation and characterization of ZnSe/CdSe core-shell microspheres

The preparation of Zn Se/Cd Se core-shell structure nanocomposites by using the re-prepared Zn Se microspheres as the template under the hydrothermal condition was presented. The influence of different mole ratios of ZnS e to Cd（NO3）2 on the morphology and structure of the final product was investigated. And the performances of ZnS e/Cd Se core-shell structure nanocomposites were characterized by the means of X-ray diffraction（XRD） analyses, scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and photoluminescence（PL） spectroscopy. The results indicate that the core-shell structure product can be prepared, when the mole ratio of Zn Se to Cd（NO3）2 is larger than 1：1; and the product will be ball solid structure, when the mole ratio of Zn Se to Cd（NO3）2 is equal to 1：1. The photo luminescence results show that Zn Se/Cd Se core-shell structures have high photo luminescence emission properties, and the product with mole ratio of Zn Se to Cd（NO3）2 being 1：0.5 has the best luminescence properties.

Synthesis and Characterization of Cobalt-Carbon Core-Shell Microspheres in Supercritical Carbon Dioxide System

The synthesis of cobalt-carbon core-shell microspheres in supercritical carbon dioxide system was investi- gated. Cobalt-carbon core-shell microspheres with diameter of about 1μm were prepared at 350 ℃ for 12 h in a closed vessel containing an appropriate amount of bis（cyclopentadienyl）cobalt powder and dry ice. Characterization by a variety of techniques, including X-ray powder diffraction, X-ray photoelectron spectroscopy, TransmissiOn electron microscope, Fourier transform infrared spectrum and Raman spectroscopy analysis reveals that each cobalt-carbon core-shell microsphere is made up of an amorphous cobalt core with diameter less than 1 μm and an amorphous carbon shell with thickness of about 200 nm. The possible growth mechanism of cobalt-carbon core-shell microspheres is discussed, based on the pyrolysis of bis（cyclopentadienyl）cobalt in supercritical carbon dioxide and the deposition of carbon or carbon clusters with odd electrons on the surface of magnetic cobalt cores due to magnetic attraction. Magnetic measurements show 141.41 emu/g of saturation magnetization of a typical sample, which is lower than the 168 emu/g of the corresponding metal cobalt bulk material. This is attributed to the considerable mass of the carbon shell and amorphous nature of the magnetic core. Control of magnetism in the cobalt-carbon core-shell microspheres was achieved by annealing treatments.

Two-step Synthesis of TiC_(0.7)N_(0.3)@WC-MoC_2 Core-shell Microspheres and Fabrication of TiC_(0.7)N_(0.3)@WC-MoC_2-based Cermets by SPS

The precursor with TiC0.7N0.3@WO3-MO3 microspheres were prepared by a novel method from the WO3-MoO3 sol dipping. Subsequently, TiC0.7N0.3@WC-MoC2 core-shell structural microspheres were successfully obtained by carburizing the precursor at 900 °C in a flowing mixture of CH4 （20 ml·min-1） and H2 （200 ml·min-1） for 2 h. Then TiC0.7N0.3@WC-MoC2-15Co cermets were prepared utilizing the core-shell powders by spark plasma sintering （SPS）. Powders of the precursors with TiC0.7N0.3@WO3-MO3 microspheres, TiC0.7N0.3@WC-MoC2 microspheres and TiC0.7N0.3@WC-MoC2-15Co cermets were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and X-ray diffraction （XRD）. The obtained TiC0.7N0.3@WC-MoC2 microspheres have a dense WC-MoC2 coatings shell. The thickness of the shell could be easily controlled by adjusting the number of sol dipping cycles. It was found that the TiC0.7N0.3@WC-MoC2 microspheres were more beneficial to fabricate the ＂core-rim＂ structures by SPS.

MoSe_(2)/TiO_(2)heterostructure integrated in N-doped carbon nanosheets assembled porous core-shell microspheres for enhanced sodium storage

Engineering the structure and composition of electrode materials is one of the essential means for achieving excellent electrochemical performance.The rational design of Na+host materials is still a massive challenge for sodium ion batteries(SIBs).Herein,MoSe_(2)/TiO_(2)heterostructure is integrated with N-doped carbon nanosheets to assemble into hierarchical flowerlike porous core-shell microspheres(MoSe_(2)/TiO_(2)@N-C),which is firstly reported by room-temperature stirring coupled with vulcanization treatment.The cavity of the core-shell structure could provide enough storage space for Na+and alleviate the volume expansion during charge/discharge processes.The apertures between nanosheets provide a guarantee for the rapid penetration of electrolyte to enhance the utilization rate of electrode materials.Furthermore,building heterostructures by combining different phase structures can facilitate electron transfer and accelerate reaction kinetics.Benefiting from the synergistic contributions of structure and composition,MoSe_(2)/TiO_(2)@N-C as SIBs anode material shows better reversible capacities of 302.5 mAh·g^(-1)at 1 A·g^(-1)for 400 cycles and 217.4 mAh·g^(-1)at 4 A·g^(-1)for 900 cycles.Strikingly,the reversible capacities can be restored entirely to the initial level after a high current density cycle.

Highly sensitive detection of phosphopeptides with superparamagnetic Fe_(3)O_(4)@mZrO_(2) core-shell microspheres-assisted mass spectrometry

Protein phosphorylation is one of the most important post-translational modifications.It is an active research area to study phosphoproteomics for discovery of disease biomarkers and druggable targets.Here we report the development of superparamagnetic Fe_(3)O_(4)@mZrO_(2) core-shell microspheres with mesoporous structures for highly efficient enrichment of phosphopeptides.We have demonstrated that the mesoporous ZrO_(2) layer dramatically improves the selective enrichment of phosphopeptides.Our approach allows for in-situ elution and sensitive identification of both mono-phosphorylated and multiphosphorylated peptides in MALDI-TOF mass spectrometry,with the detection limit of down to the femtomole range.The target phosphopeptides can reliably be enriched for MS analysis from various complex samples including the spiked protein digests and tumor cell lysates.The Fe_(3)O_(4)@mZrO_(2) coreshell microspheres promise a useful tool for phosphoproteomics by allowing for highly efficient and selective enrichment of the crucial signaling regulators in a low abundance.

Sol-gel synthesis and photoluminescence properties of BaSO_4/Y_2O_3:Eu^(3+) core-shell submicrospheres

Europium-doped nanocrystalline Y2O3 phosphor layers were coated on the surface of preformed submicron BaSO4 spheres via the sol-gel process.The obtained BaSO4/Y2O3:Eu3+ core-shell phosphors were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS) and photoluminescence spectra.The results showed that the obtained BaSO4/Y2O3:Eu3+ core-shell phosphors consisted of well-dispersed submicron spherical particles with na...

Controlled Synthesis of Core-Shell Nickel Microspheres with Solid Core and Porous Shell by Precipitation and Thermal Decomposition Method

Nickel oxalate micro-spheres with core-shell structure of solid core and radiate shell were synthesized by precipitation method in a mixed water solution, with oxalic acid and nickel acetate as raw materials, through dropping ammonium hydroxide to adjust the solution pH value to about 8.0. Nickel microspheres with core-shell structure of solid core and porous shell were prepared by decomposing of nickel oxalate microspheres precursor at about 340 ℃ in argon atmosphere. The analyses of infrared spectroscopy(IR)indicates that the composition of the powders is nickel oxalate. The analyses of atomic absorption spectrometry(AAS) and organic elemental analysis(OEA) indicate that the molar ratio of(C2O4)^2-/Ni^2+ is about 1.02, close to the theoretical value of 1.0. The results of the thermo-gravimetric and differential thermal gravity analyses(TG-DTG) indicate that the molar ratio of(C2O4)^2-/Ni^2+ is about 1.06, also close to the theoretical value of 1.0.The analysis of X-ray diffraction(XRD) indicates that the composition of black powders as-prepared is nickel,which has a face-centered cubic crystal structure with average crystal grain size about 16.87 nm. The images of scanning electron microscopy(SEM) indicate that the morphology of nickel oxalate microspheres is a coreshell structure with solid core and radiate shell. The diameter of nickel oxalate microspheres is about 3 μm, and the shell consists of a large number of thin nanorods. The images of SEM also indicate that the morphology of nickel microspheres is a core-shell structure with solid core and porous shell. The diameter of nickel microspheres is about 2 μm, and the shell consists of a large number of nickel grains, surface holes and through holes. The diameter of nickel grains is about 50-100 nm, and the diameter of holes is about 50-200 nm.

Synthesis of SiO_2@SiO_2 core-shell microspheres using urea-formaldehyde polymers as the templates for fast separation of small solutes and proteins

Superficially porous core-shell silica microspheres （CSSMs） have been a great success for the fast separation of small molecules and proteins in recent years. In this paper, the CSSMs were synthesized by an improved polymerization-induced colloid aggregation （PICA） method using urea-formaldehyde polymers as the templates. The agglomeration of the functionalized silica core was avoided by the surface modification through reflux with ureidopropyltrimethoxysilane in the neutral ethanol solution at 80 ~C, and the secondary nucleation of the silica nanoparticles during the preparation process could also be inhibited via the optimization of the reaction conditions, such as pH, temperature, colloidal silica sol concentration and the reaction time. The controllable shell thickness and pore size of the synthesized monodisperse CSSMs were successfully obtained by adjusting the weight ratio of silica core/colloidal silica sol and the particle size of colloidal silica sol, respectively. The C18-modified CSSMs with different pore sizes were used to separate small solutes and proteins. The higher efficient separation and relatively low back pressure of the synthesized core-shefi column demonstrate that the CSSMs have a great ootential aoolication for fast HPLC

Fabrication of magnetic nanosized γ-FeNi-coated ceramic core-shell microspheres by heterogeneous precipitation and thermal reduction

Precursors with NiCO3-2Ni（OH）2.2H2O- and Fe203.nH20-coated alumina, graphite and cenosphere were synthesized by precipitation using ferrous sulfate, nickel sulfate, ammonium bicarbonate, alumina, graphite and cenosphere as the main starting materials. Magnetic γ-FeNi-coated alumina, graphite and cenosphere core-shell structural microspheres were subsequently prepared by thermal reduction of the as-prepared precursors at 600℃ for 2 h. Precipitation parameters, e.g. concentration of ceramic micropowders （lOg/L）, sulfate solution （0.2mol/L）, rate of adding reactants （3 mL/min） and pH value were optimized by a trial-and-error method. Powders of the precursors and the resulting coating of γ-FeNi with grain size below 40 nm on alumina, graphite and cenosphere microspheres were characterized by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. The magnetic properties of the nanosize γ-FeNi-coated alumina, graphite and cenosphere microspheres were measured by vibrating sample magnetometer （VSM）. The results show that the core-shell structural γ-FeNi-coated ceramic microspheres exhibited higher coercivity than pure γ-FeNi powders, indicating that these materials can be used for high-Derformance functional materials and devices.

Luminescent-plasmonic core-shell microspheres,doped with Nd3+ and modified with gold nanoparticles,exhibiting whispering gallery modes and SERS activity

Multifunctional core/shell type,luminescent-plasmonic material composed of lanthanide doped microspheres(≈50μm)and gold nanoparticles(Au NPs;≈10-20 nm)deposited onto their surface,were successfully prepared(Nd^3+:YAS@Au).The material was synthesized to combine the luminescence properties of the Nd^3+-doped microspheres,i.e.whispering resonance with plasmonic activity of the surface Au NPs,i.e.surface enhanced Raman scattering(SERS)effect,within a single,micro-sized material.The luminescent-plasmonic microspheres were used as the active SERS substrate for detection of the organic probe,and for generation of Whispering Gallery Modes(WGM),which red-shift together with increasing laser power(temperature elevation).The products obtained were analysed with optical,scanning and transmission electron microscopy(SEM and TEM),as well as by Raman,absorption and photoluminescence spectroscopies.

NARROW-DISPERSED CROSSLINKED CORE-SHELL POLYMER MICROSPHERES PREPARED BY SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

Grafting of polystyrene with narrowly dispersed polymer microspheres through surface-initiated atom transferradical polymerization(ATRP)was investigated.Polydivinylbenzene(PDVB)microspheres were prepared by dispersionpolymerization with poly(N-vinyl pyrrolidone)(PVP)as stabilizer.The surfaces of PDVB microspheres werechloromethylated by chloromethyl methyl ether in the presence of zinc chloride as catalyst to form chloromethylbenzeneinitiating core sites for subsequent ATRP grafting of styrene using CuCl/bpy as catalytic system.Polystyrene was found to begrafted not only from the particle surfaces but also from within a thin shell layer,resulting in the formation of particles sizeincreased from 2.38-2.58 μm,which can further grow to 2.93 μm during secondary grafting polymerization of styrene.Thisdemonstrates that grafting polymerization proceeds through a typical ATRP procedure with living nature.All of the preparedmicrospheres have narrow particle size distribution with coefficient of variation around 10%.

Superhydrophobic Surface-Assisted Preparation of Microspheres and Supraparticles and Their Applications

Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them to retain spherical shapes, and the low adhesion of SHS facilitates easy droplet collection when tilting the substrate. These characteristics make SHS suitable for a wide range of applications. One particularly promising application is the fabrication of microsphere and supraparticle materials. SHS offers a distinct advantage as a universal platform capable of providing customized services for a variety of microspheres and supraparticles. In this review, an overview of the strategies for fabricating microspheres and supraparticles with the aid of SHS, including cross-linking process, polymer melting,and droplet template evaporation methods, is first presented. Then, the applications of microspheres and supraparticles formed onto SHS are discussed in detail, for example, fabricating photonic devices with controllable structures and tunable structural colors, acting as catalysts with emerging or synergetic properties, being integrated into the biomedical field to construct the devices with different medicinal purposes, being utilized for inducing protein crystallization and detecting trace amounts of analytes. Finally,the perspective on future developments involved with this research field is given, along with some obstacles and opportunities.

Synthesis of Core-shell ZSM-5@ Ordered Mesoporous Silica by Tetradecylamine Surfactant

A core-shell composite consisting of ZSM-5 zeolite as the core and ordered mesoporous silica as the shell was prepared by a surfactant-controlled sol-gel process and using tetradecylamine(TDA) as the template and Tetraethylorthosilicate(TEOS) as the silica precursor.The pores of the silica shell were found to be ordered and perpendicular to the crystal faces of the zeolite core.The thickness of the shell in the coreshell structured composite can be adjusted in the range of 20-90 nm,while the surface morphology and the pore size distribution were modified by changing the mass ratio of TEOS to zeolite.The composite molecular sieves have higher surface area for capturing molecules than ZSM-5,and with the increase of mesoporous shell layer,the ZSM-5@SiO_(2)-x composites show stronger adsorption capacity of butyraldehyde.However,when the shell thickness exceeds 90 nm,the adsorption capacity of butyraldehyde decreases instead.The composites have a huge potential for environmental applications.

Synthesizing core-shell Ni-rich LiNi_(x)Co_(y)Mn_(z)O_(2) from spent Li-ion battery leachate

As the global electric vehicle market continues to grow,the recycling of Li-ion battery (LIB) becomes more important worldwide and the resynthesis of cathode materials would be the most value-added recycling approach taking into account limited metal resources.Although resynthesized homogenous LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM) from spent LIB leachate shows comparable battery performance to pristine NCM from virgin materials,there is general concern in its cycling performance.Here,we synthesize core–shell(CS) Ni-rich NCM,which consists of Ni-rich NCM as the core and NCM derived from the original or purified leachate of spent LIBs as the shell.Resynthesized CS Ni-rich NCM exhibits improved rate capability resulting from expanded interslab thickness in the NCM structure.CS Ni-rich NCM from purified LIB leachate shows improvement in cycling performance and thermal stability.It specifically delivers a capacity retention of 86.6%at a high temperature after 80 cycles compared to that (75.0%) of pristine CS Ni-rich NCM.These improvements are caused by a relatively high Mg content on the shell and the widespread distribution of Al through the CS structure.CS Ni-rich NCM derived from spent LIB leachate provides a new alternative approach to conventional LIB recycling methods,which would utilize efficiently limited metal resources for the sustainable LIB production.

Core-Shell Semiconductor-Graphene Nanoarchitectures for Efficient Photocatalysis:State of the Art and Perspectives

Semiconductor photocatalysis holds great promise for renewable energy generation and environment remediation,but generally suffers from the serious drawbacks on light absorption,charge generation and transport,and structural stability that limit the performance.The core-shell semiconductorgraphene(CSSG)nanoarchitectures may address these issues due to their unique structures with exceptional physical and chemical properties.This review explores recent advances of the CSSG nanoarchitectures in the photocatalytic performance.It starts with the classification of the CSSG nanoarchitectures by the dimensionality.Then,the construction methods under internal and external driving forces were introduced and compared with each other.Afterward,the physicochemical properties and photocatalytic applications of these nanoarchitectures were discussed,with a focus on their role in photocatalysis.It ends with a summary and some perspectives on future development of the CSSG nanoarchitectures toward highly efficient photocatalysts with extensive application.By harnessing the synergistic capabilities of the CSSG architectures,we aim to address pressing environmental and energy challenges and drive scientific progress in these fields.

Recent advances in core-shell organic framework-based photocatalysts for energy conversion and environmental remediation

Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy crisis.Among a variety of materials developed as photocatalysts,the core-shell metal/covalent-organic framework(MOF or COF)photocatalysts have garnered significant attention due to their highly porous structure and the adjustability in both structure and functionality.The existing reviews on core-shell organic framework photocatalytic materials have mainly focused on core-shell MOF materials.However,there is still a lack of indepth reviews specifically addressing the photocatalytic performance of core-shell COFs and MOFs@COFs.Simultaneously,there is an urgent need for a comprehensive review encompassing these three types of core-shell structures.Based on this,this review aims to provide a comprehensive understanding and useful guidelines for the exploration of suitable core-shell organic framework photocatalysts towards appropriate photocatalytic energy conversion and environmental governance.Firstly,the classification,synthesis,formation mechanisms,and reasonable regulation of core-shell organic framework were summarized.Then,the photocatalytic applications of these three kinds of core-shell structures in different areas,such as H_(2)evolution,CO_(2)reduction,and pollutants degradation are emphasized.Finally,the main challenges and development prospects of core-shell organic framework photocatalysts were introduced.This review aims to provide insights into the development of a novel generation of efficient and stable core-shell organic framework materials for energy conversion and environmental remediation.

One-pot Synthesis of Hierarchical Flower-like WS_(2) Microspheres as Anode Materials for Lithium-ion Batteries

3D hierarchical flowerlike WS_(2) microspheres were synthesized through a facile one-pot hydrothermal route.The as-synthesized samples were characterized by powder X-ray powder diffraction (XRD),energy-dispersive spectroscopy (EDS),scanning electron microscopy (SEM) and Raman.SEM images of the samples reveal that the hierarchical flowerlike WS_(2) microspheres with diameters of about 3-5μm are composed of a number of curled nanosheets.Electrochemical tests such as charge/discharge,cyclic voltammetry,cycle life and rate performance were carried out on the WS_(2) sample.As an anode material for lithium-ion batteries,hierarchical flowerlike WS_(2) microspheres show excellent electrochemical performance.At a current density of100 mA·g^(-1),a high specific capacity of 647.8 mA·h·g^(-1) was achieved after 120 discharge/charge cycles.The excellent electrochemical performance of WS_(2) as an anode material for lithium-ion batteries can be attributed to its special 3D hierarchical structure.

Amorphous core-shell NiMoP@CuNWs rod-like structure with hydrophilicity feature for efficient hydrogen production in neutral media

Using interface engineering,a highly efficient catalyst with a shell@core structure was successfully synthesized by growing an amorphous material composed of Ni,Mo,and P on Cu nanowires(Ni-MoP@CuNWs).This catalyst only requires an overpotential of 35 mV to reach a current density of 10 mA cm^(-2).The exceptional hydrogen evolution reaction(HER)activity is attributed to the unique amorphous rod-like nature of NiMoP@CuNWs,which possesses a special hydrophilic feature,en-hances mass transfer,promotes effective contact between the electrode and electrolyte solution,and exposes more active sites during the catalytic process.Density functional theory revealed that the introduction of Mo weakens the binding strength of the Ni site on the catalyst surface with the H atom and promotes the desorption process of the H_(2) product significantly.Owing to its facile syn-thesis,low cost,and high catalytic performance,this electrocatalyst is a promising option for com-mercial applications as a water electrolysis catalyst.

A novel Ag/ZnO core-shell structure for efficient sterilization synergizing antibiotics and subsequently removing residuals

The massive use of antibiotics has led to the aggravation of bacterial resistance and also brought environmental pollution problems.This poses a great threat to human health.If the dosage of antibiotics is reduced by increasing its bactericidal performance,the emergence of drug resistance is certainly delayed,so that there's not enough time for developing drug resistance during treatment.Therefore,we selected typical representative materials of metal Ag and semiconductor ZnO nano-bactericides to design and synthesize Ag/ZnO hollow core-shell structures(AZ for short).Antibiotics are grafted on the surface of AZ through rational modification to form a composite sterilization system.The research results show that the antibacterial efficiency of the composite system is significantly increased,from the sum(34.7%+22.8%-57.5%)of the antibacterial efficiency of AZ and gentamicin to 80.2%,net synergizes 22.7%,which fully reflects the effect of 1+1>2.Therefore,the dosage of antibiotics can be drastically reduced in this way,which makes both the possibility of bacterial resistance and medical expenses remarkably decrease.Subsequently,residual antibiotics can be degraded under simple illumination using AZ-self as a photocatalyst,which cuts off the path of environmental pollution.In short,such an innovative route has guiding significance for drug resistance.

Exploring the Core-shell Structure of BaTiO3-based Dielectric Ceramics Using Machine Learning Models and Interpretability Analysis

A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their interpretability was analyzed by using Shapley additive explanations(SHAP).An F1-score changed from 0.8795 to 0.9310,accuracy from 0.8450 to 0.9070,precision from 0.8714 to 0.9000,recall from 0.8929 to 0.9643,and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features,demonstrating the high accuracy of our model and its high robustness.During the interpretability analysis of the model,it was found that the electronegativity,melting point,and sintering temperature of the dopant contribute highly to the formation of the core-shell structure,and based on these characteristics,specific ranges were delineated and twelve elements were finally obtained that met all the requirements,namely Si,Sc,Mn,Fe,Co,Ni,Pd,Er,Tm,Lu,Pa,and Cm.In the process of exploring the structure of the core-shell,the doping elements can be effectively localized to be selected by choosing the range of features.