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The pursuit of efficient and sustainable hydrogen production through water splitting has led to intensive research in the field of electrocatalysis. However, the impediment posed by sluggish reaction kinetics has served as a significant barrier. This challenge has inspired the development of electrocatalysts characterized by high activity, abundance in earth's resources, and long-term stability. In addressing this obstacle, it is imperative to meticulously fine-tune the structure, morphology, and electronic state of electrocatalysts. By systematically manipulating these key parameters, the full potential of electrocatalysts can unleash, enhancing their catalytic activity and overall performance. Hence in this study, a novel heterostructure is designed, showcasing core-shell architectures achieved by covering W2N-WC nanowire arrays with tri-metallic Nickel-Cobalt-Iron layered triple hydroxide nanosheets on carbon felt support (NiCoFe-LTH/W2N-WC/CF). By integrating the different virtue such as binder free electrode design, synergistic effect between different components, core-shell structural advantages, high exposed active sites, high electrical conductivity and heterostructure design, NiCoFe-LTH/W2N-WC/CF demonstrates striking catalytic performances under alkaline conditions. The substantiation of all the mentioned advantages has been validated through electrochemical data in this study. According to these results NiCoFe-LTH/W2N-WC/CF achieves a current density of 10 mA cm-2 needs overpotential values of 101 mV for HER and 206 mV for OER, respectively. Moreover, as a bi-functional electrocatalyst for overall water splitting, a two-electrode device needs a voltage of 1.543 V and 1.569 V to reach a current density of 10 mA cm-2 for alkaline water and alkaline seawater electrolysis, respectively. Briefly, this research with attempting to combination of different factors try to present a promising stride towards advancing bi-functional catalytic activity with tailored architectures for practical green hydrogen production via electrochemical water splitting process.

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Waste beverages are utilized as resources in various valuable, albeit energy-consuming, waste-to-energy processes. There is a growing need for alternative cost-effective methods to harness their potential. This study explored the feasibility of employing waste beverages as feedstock for the counterpart component of a TiO2-based composite photocatalyst. Several commonly available carbonated soft drinks from the Japanese market have been investigated to achieve this goal. The investigation revealed that a mild hydrothermal treatment condition could transform all examined beverages into carbonaceous materials suitable for fabricating a core-shell structure with TiO2, resulting in a remarkably efficient visible light active photocatalyst. Notably, a pH-adjusted photocatalyst derived from Coca Cola® exhibited superior visible light photodegradability toward dye molecules and enhanced bactericidal efficacy compared to the counterpart derived from pure sucrose. The heightened visible light photocatalytic activity can be attributed to the distinctive carboxy-rich surface functional groups, based on the findings of experimental analyses and density functional theory calculations. The bidentate-type bonding of these groups with TiO2 induces a modified interfacial bond structure that facilitates the efficient transfer of photoexcited carriers. This study presents a novel avenue for the effective utilization and recycling of waste beverages, and adds value under environmentally benign conditions.

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Solution-processed and efficient yellow quantum dot light-emitting diodes (QLEDs) are considered key optoelectronic devices for lighting, display, and signal indication. However, limited synthesis routes for yellow quantum dots (QDs), combined with inferior stress-relaxation of the core-shell interface, pose challenges to their commercialization. Herein, a nanostructure tailoring strategy for high-quality yellow CdZnSe/ZnSe/ZnS core/shell QDs using a "stepwise high-temperature nucleation-shell growth" method is introduced. The synthesized CdZnSe-based QDs effectively smoothed the release stress of the core-shell interface and revealed a near-unit photoluminescence quantum yield, with nonblinking behavior and matched energy level, which accelerated radiative recombination and charge injection balance for device operation. Consequently, the yellow CdZnSe-based QLEDs exhibited a peak external quantum efficiency of 23.7%, a maximum luminance of 686 050 cd m-2, and a current efficiency of 103.2 cd A-1, along with an operating half-lifetime of 428 523 h at 100 cd m-2. To the best of the knowledge, the luminance and operational stability of the device are found to be the highest values reported for yellow LEDs. Moreover, devices with electroluminescence (EL) peaks at 570-605 nm exhibited excellent EQEs, surpassing 20%. The work is expected to significantly push the development of RGBY-based display panels and white LEDs.

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In the current project, magnetic Bio-MOF-13 was used as an efficient carrier for the targeted delivery and controlled release of doxorubicin (DOX) to MDA-MB-231 cells. Magnetic Bio-MOF-13 was prepared by two strategies and compared to determine the optimal state of the structure. In the first path, Bio-MOF-13 was grown in situ on the surface of Fe3O4 nanoparticles (core/shell structure), while in the second method, the two presynthesized materials were mixed together (surface composite). Core/shell structure, among prepared nanocomposites, was chosen for biological evaluation due to its favorable structural features like a high accessible surface area and pore volume. Also, it is highly advantageous for drug release due to its ability to selectively release DOX in the acidic pH of breast cancer cells, while preventing any premature release in the neutral pH of the blood. Drug release from the carrier structure is precisely controlled not only by pH but also by an external magnetic field, guaranteeing accurate drug delivery at the intended location. Confocal microscopy and flow cytometry assay clearly confirms the increase in drug concentration in the MDA-MB-231 cell line after external magnet applying. This point, along with the low toxicity of the carrier components, makes it a suitable candidate for injectable medicine. According to MTT results, the percentage of viable MDA-MB-231 cells after treatment with 10 µL of DOX@Fe3O4/Bio-MOF-13 core/shell composite in different concentrations, in the presence and absence of magnetic field is 0.87 ± 0.25 and 2.07 ± 0.15, respectively. As a result, the DOX@Fe3O4/Bio-MOF-13 core/shell composite was performed and approved for targeted drug delivery and magnetic field-assisted controlled release of DOX to the MDA-MB-231 cell line.

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A bimetallic core-shell nanostructure is a versatile platform for achieving intriguing optical and catalytic properties. For a long time, this core-shell nanostructure has been limited to ones with noble metal cores. Otherwise, a galvanic replacement reaction easily occurs, leading to hollow nanostructures or completely disintegrated ones. In the past few years, great efforts have been devoted to preventing the galvanic replacement reaction, thus creating an unconventional class of core-shell nanostructures, each containing a less-stable-metal core and a noble metal shell. These new nanostructures have been demonstrated to show unique optical and catalytic properties. In this work, we first briefly summarize the strategies for synthesizing this type of unconventional core-shell nanostructures, such as the delicately designed thermodynamic control and kinetic control methods. Then, we discuss the effects of the core-shell nanostructure on the stabilization of the core nanocrystals and the emerging optical and catalytic properties. The use of the nanostructure for creating hollow/porous nanostructures is also discussed. At the end of this review, we discuss the remaining challenges associated with this unique core-shell nanostructure and provide our perspectives on the future development of the field.

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Zearalenone (ZEN) is a prevalent mycotoxin identified in corn. A SERS-based immunosensor by constructing core-satellite assemblies was developed for ZEN detection. ZEN monoclonal antibody modified gold nanostars (AuNSs) were fabricated as the capture probe (core). The Raman signal probes (satellites) utilized ZEN antigen linked to the core-shell structures loaded with two layers of Raman reporter molecules (AuMBA@AgMBANPs). The coupling between AuNSs and AuMBA@AgMBANPs can produce a poweful electromagnetic field, thus considerably amplifying the Raman signal. The detection range of ZEN for corn samples under the optimal conditions was 5 âˆ¼ 400 µg/kg with a LOD of 3 µg/kg, which completely satisfying the requirement of maximum residual level (60 µg/kg). Moreover, the proposed SERS method was consistent with the HPLC-FLD method for the detection of ZEN in naturally contaminated corn samples (90.58% ∼ 105.29%). Conclusively, fabricated immunosensor with exceptional sensitivity and specificity broaden the application of SERS in mycotoxin detection.

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In the present study, a novel magnetic ethylene-based periodic mesoporous organosilica supported Pd-Schiff base complex (Fe3O4@PMO/SB-Pd) was prepared, characterized and applied as a recoverable nanocatalyst for green synthesis of Suzuki products. Chemical composition, magnetic and thermal behavior, morphology and particle size of Fe3O4@PMO/SB-Pd were investigated by using FT-IR, TGA, EDX, VSM, PXRD, TEM and Scanning electron microscopy (SEM) analyses. The Fe3O4@PMO/SB-Pd nanocomposite was applied as an efficient nanocatalyst in the Suzuki reaction under ultrasonic conditions giving corresponding products in high yield. Some advantages of this study are simple purification of products, the use of water solvent, easy catalyst separation, short reaction time and high catalyst efficiency and recoverability.

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Rationally combining designed supports and metal-based nanomaterials is effective to synergize their respective physicochemical and electrochemical properties for developing highly active and stable/durable electrocatalysts. Accordingly, in this work, sub-5 nm and monodispersed nanodots (NDs) with the special nanostructure of an ultrafine Cu1Au1 core and a 2-3-atomic-layer Cu1Pd3 shell are synthesized by a facile solvothermal method, which are further evenly and firmly anchored onto 3D porous N-doped graphene nanosheets (NGS) via a simple annealing (A) process. The as-obtained Cu1Au1@Cu1Pd3 NDs/NGS-A exhibits exceptional electrocatalytic activity and noble-metal utilization toward the alkaline oxygen reduction, methanol oxidation, and ethanol oxidation reactions, showing dozens-fold enhancements compared with commercial Pd/C and Pt/C. Besides, it also has excellent long-term electrochemical stability and electrocatalytic durability. Advanced and comprehensive experimental and theoretical analyses unveil the synthetic mechanism of the special core@shell nanostructure and further reveal the origins of the significantly enhanced electrocatalytic performance: (1) the prominent structural properties of NGS, (2) the ultrasmall and monodispersed size as well as the highly uniform morphology of the NDs-A, (3) the special Cu-Au-Pd alloy nanostructure with an ultrafine core and a subnanometer shell, and (4) the strong metal-support interaction. This work not only develops a facile method for fabricating the special metal-based ultrafine-core@ultrathin-shell nanostructure but also proposes an effective and practical design paradigm of comprehensively and rationally considering both supports and metal-based nanomaterials for realizing high-performance multifunctional electrocatalysts, which can be further expanded to other supports and metal-based nanomaterials for other energy-conversion or environmental (electro)catalytic applications.

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II-V semiconductor nanocrystals such as Cd3P2 and Zn3P2 have enormous potential as materials in next-generation optoelectronic devices requiring active optical properties across the visible and infrared range. To date, this potential has been unfulfilled due to their inherent instability with respect to air and moisture. Core-shell system Cd3P2/Zn3P2 is synthesized and studied from structural (morphology, crystallinity, shell diameter), chemical (composition of core, shell, and ligand sphere), and optical perspectives (absorbance, emission-steady state and time resolved, quantum yield, and air stability). The improvements achieved by coating with Zn3P2 are likely due to its identical crystal structure to Cd3P2 (tetragonal), highlighting the key role crystallographic concerns play in creating cutting edge core-shell NCs.

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Transition metals have been recognized as excellent and efficient catalysts for the electrochemical nitric oxide reduction reaction (NORR) to value-added chemicals. In this work, a class of core-shell electrocatalysts that utilize nickel nanoparticles in the core and nitrogen-doped porous carbon architecture in the shell (Ni@NC) for the efficient electroreduction of NO to ammonia (NH3 ) is reported. In Ni@NC, the NC prevents the dissolution of Ni nanoparticles and ensures the long-term stability of the catalyst. The Ni nanoparticles involve in the catalytic reduction of NO to NH3 during electrolysis. As a result, the Ni@NC achieves a faradaic efficiency (FE) of 72.3% at 0.16 VRHE . The full-cell electrolyzer is constructed by coupling Ni@NC as cathode for NORR and RuO2 as an anode for oxygen evolution reaction (OER), which delivers a stable performance over 20 cycles at 1.5 V. While integrating this setup with a PV-electrolyzer cell, and it demonstrates an appreciable FE of >50%. Thus, the results exemplify that the core-shell catalyst based electrolyzer is a promising approach for the stable NO to NH3 electroconversion.

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Anisotropic strain engineering has emerged as a powerful strategy for enhancing the optoelectronic performance of semiconductor nanocrystals. Here, we show that CdSe/CdS dot-in-rod structures offer a platform for fine-tuning the optical response of CdSe quantum dots through anisotropic strain. By controlling the spatial position of the CdSe core within a growing CdS nanorod shell, varying degrees of uniaxial strain can be introduced. Placing CdSe cores at the end of the CdS nanorod induces strong asymmetric compression along the c-axis of the wurtzite CdSe core, dramatically altering its absorption and emission characteristics, whereas CdSe cores located near the middle of the nanorod experience a comparatively weak uniaxial strain field. The change in absorption and emission spectra and dynamics for highly strained end-position CdSe/CdS nanorods is explained by (1) relative shifting of the valence band light hole and heavy hole levels and (2) introduction of a strong piezoelectric potential, which spatially separates the electron and hole wave functions. The ability to tune the degree of uniaxial strain through core position control in a nanorod structure creates opportunities for precisely modulating the electronic properties of CdSe nanocrystals while simultaneously taking advantage of dielectric and optical anisotropies intrinsic to 1D nanostructures.

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With the deterioration of the ecological environment and the depletion of fossil energy, fuel cells, representing a new generation of clean energy, have received widespread attention. This review summarized recent progress in noble metal-based core-shell catalysts for oxygen reduction reactions (ORRs) in proton exchange membrane fuel cells (PEMFCs). The novel testing methods, performance evaluation parameters and research methods of ORR were briefly introduced. The effects of the preparation method, temperature, kinds of doping elements and the number of shell layers on the ORR performances of noble metal-based core-shell catalysts were highlighted. The difficulties of mass production and the high cost of noble metal-based core-shell nanostructured ORR catalysts were also summarized. Thus, in order to promote the commercialization of noble metal-based core-shell catalysts, research directions and prospects on the further development of high performance ORR catalysts with simple synthesis and low cost are presented.

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Electro-catalyzed oxygen reduction reaction (ORR), as the positive electrode reaction, is significant to the performance of fuel cells and metal-air batteries. Toward ORR, ultra-small Pt@Mn core-shell nanoparticles catalysts supported on Ketjen black are synthesized by a simple one-pot hydrothermal method. TEM results show that the Pt@Mn/C nanoparticles with an average size of 3∼4 nm are uniformly distributed on the carbon surface. ORR performance of the electrocatalysts shows that Pt@Mn/C exhibits better oxygen reduction activity than Pt/C (20 wt %) in a KOH solution. Methanol tolerance ability as well as the durability of the Pt@Mn/C is also superior to the performance of Pt/C, suggesting an enhanced ORR activity upon the introduction of Mn.

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Metal-organic framework materials (MOF) have become a new generation of microwave absorption (MA) materials. However, it is still challenging to design an appropriate microstructure that can efficiently adjust the microwave absorbing characteristics. Herein, a novel bimetal-doped core-shell carbon derived from nickel-cobalt dual-ligand MOF has been successfully prepared. By changing the ratio of the second ligand, the morphology can change from sea urchin-like to rod-like and petal-like shapes, thereby regulating the final wave absorption performance of MOF derivatives. The Bi-MOF-1 exhibited strong microwave absorption (up to -70.70 dB), while Bi-MOF-2 presented broad effective absorption bandwidth (5.92 GHz). The analyses indicated that the excellent impedance matching can be attributed to the double-layer magnetic loss and multiple dielectric loss of the core-shell structure. This work provides a feasible approach for the design and preparation of functional composite structures based on MOF derivatives with controllable microwave absorbing properties.

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Nanointerconnection has been selected as a promising method in the post-Moore era to realize device miniaturization and integration. Even with many advances, the existing nanojoining methods still need further developments to meet the three-dimensional nanostructure construction requirements of the next-generation devices. Here, we proposed an efficient silver (Ag)-filled nanotube fabrication method and realized the controllable melting and ultrafine flow of the encapsulated silver at a subfemtogram (0.83 fg/s) level, which presents broad application prospects in the interconnection of materials in the nanometer or even subnanometer. We coated Ag nanowire with polyvinylpyrrolidone (PVP) to obtain core-shell nanostructures instead of the conventional well-established nanotube filling or direct synthesis technique, thus overcoming obstacles such as low filling rate, discontinuous metalcore, and limited filling length. Electromigration and thermal gradient force were figured out as the dominant forces for the controllable flow of molten silver. The conductive amorphous carbonaceous shell formed by pyrolyzing the insulative PVP layer was also verified by energy dispersive spectroscopy (EDS), which enabled the continued outflow of the internal Ag. Finally, a reconfigurable nanointerconnection experiment was implemented, which opens the way for interconnection error correction in the fabrication of nanoelectronic devices.

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Developing high-efficiency and earth-abundant electrocatalysts for electrochemical seawater-splitting is of great significance but remains a grand challenge due to the presence of high-concentration chloride. This work presents the synthesis of a three-dimensional core-shell nanostructure with an amorphous and crystalline NiFe-layered double hydroxide (NiFe-LDH) layer on sulfur-modified nickel molybdate nanorods supported by porous Ni foam (S-NiMoO4@NiFe-LDH/NF) through hydrothermal and electrodeposition. Benefiting from high intrinsic activity, plentiful active sites, and accelerated electron transfer, S-NiMoO4@NiFe-LDH/NF displays an outstanding bifunctional catalytic activity toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in both simulated alkaline seawater and natural seawater electrolytes. To reach a current density of 100 mA cm-2, this catalyst only requires overpotentials of 273 and 315 mV for OER and 170 and 220 mV for HER in 1 M KOH + 0.5 M NaCl freshwater and 1 M KOH + seawater electrolytes, respectively. Using S-NiMoO4@NiFe-LDH as both anode and cathode, the electrolyzer shows superb overall seawater-splitting activity, and respectively needs low voltages of 1.68 and 1.73 V to achieve a current density of 100 mA cm-2 in simulated alkaline seawater and alkaline natural seawater electrolytes with good Cl- resistance and satisfactory durability. The electrolyzer outperforms the benchmark IrO2||Pt/C pair and many other reported bifunctional catalysts and exhibits great potential for realistic seawater electrolysis.

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Silver nanoparticles (Ag NPs) have attracted extensive research interest in bioimaging and biosensing due to their unique surface plasmon resonance. However, the potential aggregation and security anxiety of Ag NPs hinder their further application in biomedical field due to their high surface energy and the possible ionization. Here, binary heterogeneous nanocomplexes constructed from silver nanoparticles and carbon nanomaterials (termed as C-Ag NPs) were reported. The C-Ag NPs with multiple yolk structure were synthesized via a one-step solvothermal route using toluene as carbon precursor and dispersant. The hydrophilic functional groups on the carbon layer endowed the C-Ag NPs excellent chemical stability and water-dispersity. Results showed that C-Ag NPs demonstrated excellent safety profile and excellent biocompatibility, which could be used as an intracellular imaging agent. Moreover, the C-Ag NPs responded specifically to hydroxyl radicals and were expected to serve as a flexible sensor to efficiently detect diseases related to the expression of hydroxyl radicals in the future.

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Nowadays, numerous works regarding nanowires or nanotubes are being published, studying different combinations of materials or geometries with single or multiple layers. However, works, where both nanotube and nanowires are forming complex structures, are scarcer due to the underlying difficulties that their fabrication and characterization entail. Among the specific applications for these nanostructures that can be used in sensing or high-density magnetic data storage devices, there are the fields of photonics or spintronics. To achieve further improvements in these research fields, a complete understanding of the magnetic properties exhibited by these nanostructures is needed, including their magnetization reversal processes and control of the magnetic domain walls. In order to gain a deeper insight into this topic, complex systems are being fabricated by altering their dimensions or composition. In this work, a successful process flow for the additive fabrication of core/shell nanowires arrays is developed. The core/shell nanostructures fabricated here consist of a magnetic nanowire nucleus (Fe56Co44), grown by electrodeposition and coated by a non-magnetic SiO2 layer coaxially surrounded by a magnetic Fe3O4 nanotubular coating both fabricated by means of the Atomic Layer Deposition (ALD) technique. Moreover, the magnetization reversal processes of these coaxial nanostructures and the magnetostatic interactions between the two magnetic components are investigated by means of standard magnetometry and First Order Reversal Curve methodology. From this study, a two-step magnetization reversal of the core/shell bimagnetic nanostructure is inferred, which is also corroborated by the hysteresis loops of individual core/shell nanostructures measured by Kerr effect-based magnetometer.

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Amphotericin B (AmB) is an antifungal and antiparasitic agent that is the main drug used for the treatment of mycoses infections and leishmaniasis. However, its high toxicity and side effects are the main difficulties attributed to its application. In this study, to minimize its harmful effects, AmB-loaded core-shell nanofibers were fabricated, using polyvinyl alcohol, chitosan, and AmB as the core, and polyethylene oxide and gelatin as the shell-forming components. The nanofibers were characterized, using scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, tensile test, drug release, and MTT assay. The results showed that the prepared nanofibers were smooth and had a core-shell structure with almost no cytotoxicity against fibroblast cells and the release study suggested that the core-shell structure decreased the burst release. The disk diffusion assay revealed that the nanofibrous mats at different AmB concentrations exhibited significant activity against all the eight evaluated fungal species with the inhibition zones of 1.4-2.6 cm. The flow cytometry assay also showed that the prepared nanofibrous mat significantly killed Leishmania major promastigotes up to 84%. The obtained results indicated that this AmB-loaded nanofibrous system could be a suitable candidate for a topical drug delivery system for the treatment of both superficial mycoses and cutaneous leishmaniasis.

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We report that Fe3O4@Au core-shell nanoparticles (NPs) serve as a multifunctional molecule delivery platform. This platform is also suitable for sensing the doxorubicin (DOX) through DNA hybridization, and the amount of carried DOX molecules was determined by size-dependent Fe3O4@Au NPs. The limits of detection (LODs) for DOX was found to be 1.839 nM. In our approach, an Au nano-shell coating was coupled with a specially designed DNA sequence using thiol bonding. By means of a high-frequency magnetic field (HFMF), a high release percentage of such a molecule could be efficiently achieved in a relatively short period of time. Furthermore, the thickness increase of the Au nano-shell affords Fe3O4@Au NPs with a larger surface area and a smaller temperature increment due to shielding effects from magnetic field. The change of magnetic property may enable the developed Fe3O4@Au-dsDNA/DOX NPs to be used as future nanocarrier material. More importantly, the core-shell NP structures were demonstrated to act as a controllable and efficient factor for molecule delivery.