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Defect and interface engineering are efficient approaches to adjust the physical and chemical properties of nanomaterials. In order to effectively utilize these strategies for the improvement of microwave absorption properties (MAPs), in this study, we reported the synthesis of hollow carbon shells and hollow carbon@MoS 2 nanocomposites by the template-etching and template-etching-hydrothermal methods, respectively. The obtained results indicated that the degree of defect for hollow carbon shells and hollow carbon@MoS 2 could be modulated by the thickness of hollow carbon shell, which effectively fulfilled the optimization of electromagnetic parameters and improvement of MAPs. Furthermore, the microstructure investigations revealed that the precursor of hollow carbon shells was encapsulated by the sheet-like MoS 2 in high efficiency. And the introduction of MoS 2 nanosheets acting as the shell effectively improved the interfacial effects and boosted the polarization loss capabilities, which resulted in the improvement of comprehensive MAPs. The elaborately designed hollow carbon@MoS 2 samples displayed very outstanding MAPs including strong absorption capabilities, broad absorption bandwidth, and thin matching thicknesses. Therefore, this work provided a viable strategy to improve the MAPs of microwave absorbers by taking full advantage of their defect and interface engineering.

Radiotherapy (RT), a widely used clinical treatment modality for cancer, uses high-energy irradiation for reactive oxygen species (ROS) production and DNA damage. However, its therapeutic effect is primarily limited owing to insufficient DNA damage to tumors and harmful effects on normal tissues. Herein, a core-shell structure of metal–semiconductors (Au@AgBiS2 nanoparticles) that can function as pyroptosis inducers to both kill cancer cells directly and trigger a robust anti-tumor immune against 4T1 triple-negative murine breast cancer and metastasis is rationally designed. Metal-semiconductor composites can enhance the generation of considerable ROS and simultaneously DNA damage for RT sensitization. Moreover, Au@AgBiS2, a pyroptosis inducer, induces caspase-3 protein activation, gasdermin E cleavage, and the release of damage-associated molecular patterns. In vivo studies in BALB/c mice reveal that Au@AgBiS2 nanoparticles combined with RT exhibit remarkable antitumor immune activity, preventing tumor growth, and lung metastasis. Therefore, this core-shell structure is an alternative for designing highly effective radiosensitizers for radioimmunotherapy.

Due to the good manipulation of electronic structure and defect, anion regulating should be a promising strategy to regulate the electromagnetic (EM) parameters and optimize the EM wave absorption performances (EMWAPs). In this work, we proposed a facile route for the large-scale production of core@shell structured hollow carbon spheres@MoS x Se 2− x ( x = 0.2, 0.6, and 1.0) multicomponent nanocomposites (MCNCs) through a mild template method followed by hydrothermal process. The obtained results revealed that the designed hollow carbon spheres@MoS x Se 2− x MCNCs presented the improved sulfur vacancy concentration by regulating the x value from 0.2 to 1.0. The obtained hollow carbon spheres@MoS x Se 2− x MCNCs displayed the extraordinary comprehensive EMWAPs because of the introduced abundant defects and excellent interfacial effects. Furthermore, the as-prepared hollow carbon spheres@MoS x Se 2− x MCNCs presented the progressively improved comprehensive EMWAPs with the x value increasing from 0.2 to 1.0, which could be explained by their boosted polarization loss abilities and impedance matching characteristics originating from the enhanced sulfur vacancy concentration. Therefore, our findings not only demonstrated that the anion regulating was a promising method to optimize EM parameters and EMWAPs, but also provided a facile route to design the transition metal dichalcogenides-based MCNCs as the much more attractive candidates for high-performance microwave absorbers.

Cobalt ferrite (CoFe 2 O 4 ), with good chemical stability and magnetic loss, can be used to prepare composites with a unique structure and high absorption. In this study, CoFe 2 O 4 @mesoporous carbon hollow spheres (MCHS) with a core-shell structure were prepared by introducing CoFe 2 O 4 magnetic particles into hollow mesoporous carbon through a simple in situ method. Then, the microwave absorption performance of the CoFe 2 O 4 @MCHS composites was investigated. Magnetic and dielectric losses can be effectively coordinated by constructing the porous structure and adjusting the ratio of MCHS and CoFe 2 O 4 . Results show that the impedance matching and absorption properties of the CoFe 2 O 4 @MCHS composites can be altered by tweaking the mass ratio of MCHS and CoFe 2 O 4 . The minimum reflection loss of the CoFe 2 O 4 @MCHS composites reaches -29.7 dB at 5.8 GHz. In addition, the effective absorption bandwidth is 3.7 GHz, with the thickness being 2.5 mm. The boosted microwave absorption can be ascribed to the porous core-shell structure and introduction of magnetic particles. The coordination between the microporous morphology and the core-shell structure is conducive to improving the attenuation coefficient and achieving good impedance matching. The porous core-shell structure provides large solid-void and CoFe 2 O 4 −C interfaces to induce interfacial polarization and extend the electromagnetic waves’ multiple scattering and reflection. Furthermore, natural resonance, exchange resonance, and eddy current loss work together for the magnetic loss. This method provides a practical solution to prepare core-shell structure microwave absorbents.

With the pace of time, synthesis of nanomaterials has paved paths to blend two or more materials having different properties into hybrid nanoparticles. Therefore, it has become possible to combine two different functionalities in a single nanoparticle and their properties can be enhanced or modified by coupling of two different components. Core–shell technology has now represented a new trend in analytical sciences. Core–shell nanostructures are in demand due to their specific design and geometry. They have internal core of one component (metal or biomolecules) surrounded by a shell of another component. Core–shell nanoparticles have great importance due to their high thermal stability, high solubility and lower toxicity. In this review, recent progress in development of new and sophisticated core–shell nanostructures has been explored. The first section covers introduction throwing light on basics of core–shell nanoparticles. Following section classifies core–shell nanostructures into single core/shell, multicore/single shell, single core/multishell and multicore/multishell nanostructures. Next main section gives a brief description on types of core–shell nanomaterials followed by processes for the synthesis of core–shell nanostructures. Ultimately, the final section focuses on the application areas such as drug delivery, bioimaging, solar cell applications etc.Graphic abstract

The development of Pt-based core/shell nanoparticles represents an emerging class of electrocatalysts for fuel cells, such as methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). Here, we present a one-pot synthesis approach to prepare hexagonal PtBi/Pt core/shell nanostructure composed of an intermetallic Pt 1 Bi 1 core and an ultrathin Pt shell with well-defined shape, size, and composition. The structure and the synergistic effect among different components enhanced their MOR and EOR performance. The optimized Pt 2 Bi nanoplates exhibit excellent mass activities in both MOR (4,820 mA·mgPt –1 ) and EOR (5,950 mA·mgPt –1 ) conducted in alkaline media, which are 6.15 times and 8.63 times higher than those of commercial Pt/C, respectively. Pt 2 Bi nanoplates also show superior operation durability to commercial Pt/C. This work may inspire the rational design and synthesis of Pt-based nanoparticles with improved performance for fuel cells and other applications.

Material composition and structural design are important factors influencing the electromagnetic wave (EMW) absorption performance of materials. To alleviate the impedance mismatch attributed to the high dielectric constant of Ti3C2Tx MXene, we have successfully synthesized core‐shell structured SiO2@MXene@MoS2 nanospheres. This architecture, comprising SiO2 as the core, MXene as the intermediate layer, and MoS2 as the outer shell, is achieved through an electrostatic self‐assembly method combined with a hydrothermal process. This complex core‐shell structure not only provides a variety of loss mechanisms that effectively dissipate electromagnetic energy but also prevents self‐aggregation of MXene and MoS2 nanosheets. Notably, the synergistic combination of SiO2 and MoS2 with highly conductive MXene enables the suitable dielectric constant of the composites, ensuring optimal impedance matching. Therefore, the core‐shell structured SiO2@MXene@MoS2 nanospheres exhibit excellent EMW absorption performance, featuring a remarkable minimum reflection loss (RLmin) of −52.11 dB (2.4 mm). It is noteworthy that these nanospheres achieve an ultra‐wide effective absorption bandwidth (EAB) of 6.72 GHz. This work provides a novel approach for designing and synthesizing high‐performance EMW absorbers characterized by “wide bandwidth and strong reflection loss.” The sandwich‐like structured SiO2@MXene@MoS2 nanospheres were synthesized by coating MoS2 nanosheets on SiO2@MXene, which is promising for strong electromagnetic wave absorption. Due to the formation of a unique structure, multiple loss mechanisms are achieved by a multipolarization synergistic effect. Thus, SiO2@MXene@MoS2 nanospheres exhibit a remarkable minimum reflection loss of −52.11 dB at 2.4 mm.

Cellular thin-shell structures are widely applied in ultralightweight designs due to their high bearing capacity and strength-to-weight ratio. In this paper, a full-scale isogeometric topology optimization (ITO) method based on Kirchhoff–Love shells for designing cellular tshin-shell structures with excellent damage tolerance ability is proposed. This method utilizes high-order continuous nonuniform rational B-splines (NURBS) as basis functions for Kirchhoff–Love shell elements. The geometric and analysis models of thin shells are unified by isogeometric analysis (IGA) to avoid geometric approximation error and improve computational accuracy. The topological configurations of thin-shell structures are described by constructing the effective density field on the control mesh. Local volume constraints are imposed in the proximity of each control point to obtain bone-like cellular structures. To facilitate numerical implementation, the p-norm function is used to aggregate local volume constraints into an equivalent global constraint. Several numerical examples are provided to demonstrate the effectiveness of the proposed method. After simulation and comparative analysis, the results indicate that the cellular thin-shell structures optimized by the proposed method exhibit great load-carrying behavior and high damage robustness.

Magnetoelectric nanoparticles (MENPs) are able to locally generate high electric fields when activated with human‐safe, low‐intensity magnetic fields. However, when implanted as individual or randomly positioned small clusters, the induced electric fields decay very quickly with the distance, hampering effective tissue stimulation. Herein, a novel nano‐structured polymeric‐based MENPs‐loaded 3D system (ME‐Patch) is designed and optimized in terms of its electrical performances through a holistic and multi‐scale in silico framework, which spans from the multi‐physics modeling of the magnetoelectric phenomenon at the nanoscale to a functional assessment of the micrometric ME‐Patch stimulation ability in a realistic model of a human peripheral nerve. This study presents the theoretical applicability of a material‐based recipe for the fabrication of effective soft and biocompatible magnetoelectric devices, able to store and transfer the extremely localized effect of individual MENPs on tissue areas and trigger neuron action potential activation. Core‐shell, magnetoelectric nanoparticles (MENPs) can serve as wireless electric nano‐sources, thanks to their ability to generate high levels of electricity, when stimulated by a human‐safe external magnetic field. By combining MENPs with soft, biocompatible polymeric matrices and optimizing its composite configuration and electrical behavior via multi‐scale and multi‐physics models, a new flexible and functional biointerface is proposed.

HighlightsA simple two-step multi-element co-doping strategy is proposed to fabricate core-shell structured LiCoO2 based on the different diffusivities of dopant ions.The high diffusivity Al3+/Mg2+ ions occupy the core of single-crystal grain while the low diffusivity Ti4+ ions enrich the shell layer. In-situ XRD demonstrates the mitigated structural distortion under a high cut-off voltage of 4.6 V, resulting in a significantly improved cycling stability.Inactive elemental doping is commonly used to improve the structural stability of high-voltage layered transition-metal oxide cathodes. However, the one-step co-doping strategy usually results in small grain size since the low diffusivity ions such as Ti4+ will be concentrated on grain boundaries, which hinders the grain growth. In order to synthesize large single-crystal layered oxide cathodes, considering the different diffusivities of different dopant ions, we propose a simple two-step multi-element co-doping strategy to fabricate core–shell structured LiCoO2 (CS-LCO). In the current work, the high-diffusivity Al3+/Mg2+ ions occupy the core of single-crystal grain while the low diffusivity Ti4+ ions enrich the shell layer. The Ti4+-enriched shell layer (~ 12 nm) with Co/Ti substitution and stronger Ti–O bond gives rise to less oxygen ligand holes. In-situ XRD demonstrates the constrained contraction of c-axis lattice parameter and mitigated structural distortion. Under a high upper cut-off voltage of 4.6 V, the single-crystal CS-LCO maintains a reversible capacity of 159.8 mAh g−1 with a good retention of ~ 89% after 300 cycles, and reaches a high specific capacity of 163.8 mAh g−1 at 5C. The proposed strategy can be extended to other pairs of low- (Zr4+, Ta5+, and W6+, etc.) and high-diffusivity cations (Zn2+, Ni2+, and Fe3+, etc.) for rational design of advanced layered oxide core–shell structured cathodes for lithium-ion batteries.