Multi-shelled Structures Research Articles

Balanced Polysulfide Containment and Lithium Ion Transport in Lithium-Sulfur Batteries via Nitrogen-doped Carbon Hollow Multi-shelled Structures on Modified Separators

Balanced Polysulfide Containment and Lithium Ion Transport in Lithium-Sulfur Batteries via Nitrogen-doped Carbon Hollow Multi-shelled Structures on Modified Separators

Rational Design of Coordination Polymers Composited Hollow Multishelled Structures for Drug Delivery.

Multifunctional drug delivery systems (DDS) are in high demand for effectively targeting specific cells, necessitating excellent biocompatibility, precise release mechanisms, and sustained release capabilities. The hollow multishelled structure (HoMS) presents a promising solution, integrating structural and compositional design for efficient DDS development amidst complex cellular environments. Herein, starting from a Fe-based metal-organic framework (MOF), amorphous coordination polymers (CP) composited HoMS with controlled shell numbers are fabricated by balancing the rate of MOF decomposition and shell formation. Fe-CP HoMS loaded with DOX is utilized for synergistic chemotherapy and chemodynamic therapy, offering excellent responsive drug release capability (excellent pH-triggered drug release 82% within 72h at pH 5.0 solution with doxorubicin (DOX) loading capacity of 284mg g-1). In addition to its potent chemotherapy attributes, Fe-CP-HoMS possesses chemodynamic therapy potential by continuously catalyzing H2O2 to generate ·OH species within cancer cells, thus effectively inhibiting cancer cell proliferation. DOX@3S-Fe-CP-HoMS, at a concentration of 12.5µg mL-1, demonstrates significant inhibitory effects on cancer cells while maintaining minimal cytotoxicity toward normal cells. It is envisioned that CP-HoMS could serve as an effective and biocompatible platform for the advancement of intelligent drug delivery systems in the realm of cancer therapy.

Visualizing Nanoscale Interlayer Magnetic Interactions and Unconventional Low-Frequency Behaviors in Ferromagnetic Multishelled Structures.

Precise manipulation of van der Waals forces within 2D atomic layers allows for exact control over electron-phonon coupling, leading to the exceptional quantum properties. However, applying this technique to diverse structures such as 3D materials is challenging. Therefore, investigating new hierarchical structures and different interlayer forces is crucial for overcoming these limitations and discovering novel physical properties. In this work, a multishelled ferromagnetic material with controllable shell numbers is developed. By strategically regulating the magnetic interactions between these shells, the magnetic properties of each shell are fine-tuned. This approach reveals distinctive magnetic characteristics including regulated magnetic domain configurations and enhanced effective fields. The nanoscale magnetic interactions between the shells are observed and analyzed, which shed light on the modified magnetic properties of each shell, enhancing the understanding and control of ferromagnetic materials. The distinctive magnetic interaction significantly boosts electromagnetic absorption at low-frequency frequencies used by fifth-generation wireless devices, outperforming ferromagnetic materials without multilayer structures by several folds. The application of magnetic interactions in materials science reveals thrilling prospects for technological and electronic innovation.

Intergrating Hollow Multishelled Structure and High Entropy Engineering toward Enhanced Mechano-Electrochemical Properties in Lithium Battery.

Hollow multishelled structures (HoMSs) are attracting great interest in lithium-ion batteries as the conversion anodes, owing to their superior buffering effect and mechanical stability. Given the synthetic challenges, especially elemental diffusion barrier in the multimetal combinations, this complex structure design has been realized in low- and medium-entropy compounds so far. It means that poor reaction reversibility and low intrinsic conductivity remain largely unresolved. Here, a hollow multishelled (LiFeZnNiCoMn)3O4 high entropy oxide (HEO) is developed through integrating molecule and microstructure engineering. As expected, the HoMS design exhibits significant targeting functionality, yielding satisfactory structure and cycling stability. Meanwhile, the abundant oxygen defects and optimized electronic structure of HEO accelerate the lithiation kinetics, while the retention of the parent lattice matrix enables reversible lithium storage, which is validated by rigorous in situ tests and theoretical simulations. Benefiting from these combined properties, such hollow multishelled HEO anode can deliver a specific capacity of 967 mAh g-1 (89% capacity retention) after 500 cycles at 0.5 A g-1. The synergistic lattice and volume stability showcased in this work holds great promise in guiding the material innovations for the next-generation energy storage devices.

Trapping of heavy metal ions from electroplating wastewater with phosphorylated double-shelled hollow spheres

The mesoporous multi-shelled hollow structures are promising for trapping of non-degradable heavy metal ions in wastewater but difficult to synthesize. We successfully demonstrated a simple strategy for the construction of mesopore windows on double-shelled α-Fe2O3 hollow spheres. A step-by-step proof of concept synthesis mechanism has been revealed by using mainly electron microscopy and thermogravimetric analysis. We proved that mesopore windows are indispensable to realize the complete surface coverage of phosphonate ligands on α-Fe2O3 double-shelled hollow spheres. The phosphonic groups inherently coordinated with Ni(II) and Cu(II) ions and formed complexes of high stability. Importantly, owing to the structural merits, the phosphorylated double-shelled hollow spheres selectively removes Ni(II) and Cu(II) at wider sample pH range with a high capacity of 380 mg g−1 and 410 mg g−1, respectively. In addition, no significant decrease in the removal efficiency was observed under high salt matrix. For electroplating industry wastewater, the novel structure performs simultaneous Ni(II) and Cu(II) removal, thus producing effluent of stable quality that meets local discharge regulations.

Facile synthesis of double yolk-shelled MnO/C microspheres as superior anode materials for lithium-ion batteries

Tenable structure design is vital in the pursuit of advanced anode materials for enhanced lithium storage, but construction of the desired architectures often faces challenges. Herein, we demonstrate the facile fabrication of double yolk-shelled MnO/C microspheres by annealing the solvothermally synthesized Mn-gluconate microspheres under Ar atmosphere, and the double or single yolk-shell structure can be easily regulated by changing the glucose amount. Benefits brought by the unique structure include enlarged surface area, hierarchical pores, abundant reaction sites and increased ion diffusion rate. Besides, combination of MnO with glucose-derived carbon could not only restrict the volume variation of MnO but also increase the electrical conductivity, bringing improved rate capability and enhanced cycling stability. Thus, a high-rate and stable capacity of 611 mAh g−1 after 500 cycles at 1 A g−1 is observed in the lithium-ion batteries adopting the presented double yolk-shelled MnO/C microspheres as the anode materials, thanks to the synergistic structure and composition advantages. Importantly, this study provides a controllable method to construct delicate multi-shelled structures with simultaneous carbon hybridization, which could be promising in fabrication of advanced electrodes for energy-related applications.

Mesoscience in Hollow Multi-Shelled Structures.

The prevalence of mesoscale complexity in materials science underscores the significance of the compromise in competition principle, which gives rise to the emergence of mesoscience. This principle offers valuable insights into understanding the formation process, characteristics, and performance of complex material systems, ultimately guiding the future design of such intricate materials. Hollow multi-shelled structures (HoMS) represent a groundbreaking multifunctional structural system that encompasses several spatial regimes. A plethora of mesoscale cases within HoMS present remarkable opportunities for exploring, understanding, and utilizing mesoscience, varying from the formation process of HoMS, to the mesoscale structural parameters, and finally the distinctive mass/energy transfer behaviors exhibited by HoMS. The compromise in competition between the diffusion and reaction contributes to the successful formation of multi-shells of HoMS, allowing for precise regulation of the structural parameters by dynamically varying the interplay between two dominances. Moreover, the distinct roles played by the shells and cavities within HoMS significantly influence the energy/mass transfer processes with the unique temporal-spatial resolution, providing guidance for customizing the application performance. Hopefully, the empirical and theoretical anatomy of HoMS following mesoscience would fuel new discoveries within this promising and complex multifunctional material system.

Constructing Hollow Multishelled Microreactors with a Nanoconfined Microenvironment for Ofloxacin Degradation through Peroxymonosulfate Activation: Evolution of High-Valence Cobalt-Oxo Species.

This study constructed hollow multishelled microreactors with a nanoconfined microenvironment for degrading ofloxacin (OFX) through peroxymonosulfate (PMS) activation in Fenton-like advanced oxidation processes (AOPs), resulting in adequate contaminant mineralization. Among the microreactors, a triple-shelled Co-based hollow microsphere (TS-Co/HM) exhibited optimal performance; its OFX degradation rate was 0.598 min-1, which was higher than that of Co3O4 nanoparticles by 8.97-fold. The structural tuning of Co/HM promoted the formation of oxygen vacancies (VO), which then facilitated the evolution of high-valence cobalt-oxo (Co(IV)═O) and shifted the entire t2g orbital of the Co atom upward, promoting catalytic reactions. Co(IV)═O was identified using a phenylmethyl sulfoxide (PMSO) probe and in situ Raman spectroscopy, and theoretical calculations were conducted to identify the lower energy barrier for Co(IV)═O formation on the defect-rich catalyst. Furthermore, the TS-Co/HM catalyst exhibited remarkable stability in inorganic (Cl-, H2PO4-, and NO3-), organic (humic acid), real water samples (tap water, river water, and hospital water), and in a continuous flow system in a microreactor. The nanoconfined microenvironment could enrich reactants in the catalyst cavities, prolong the residence time of molecules, and increase the utilization efficiency of Co(IV)═O. This work describes an activation process involving Co(IV)═O for organic contaminants elimination. Our results may encourage the use of multishelled structures and inform the design of nanoconfined catalysts in AOPs.

One-Pot Synthesis of MOF@MOF: Structural Incompatibility Leads to Core-Shell Structure and Adaptability Control Makes the Sequence.

Core-shell metal-organic frameworks (MOF@MOF) are promising materials with sophisticated structures that cannot only enhance the properties of MOFs but also endow them with new functions. The growth of isotopic lcore-shell MOFs is mostly limited to inconvenient stepwise seeding strategies with strict requirements, and by far one-pot synthesis is still of great challenge due to the interference of different components. Through two pairs of isoreticular MOFs, it reveals that the structural incompatibility is a prerequisite for the formation of MOFs@MOFs by one-pot synthesis, as illustrated by PMOF-3@HHU-9. It further unveils that the adaptability of the shell-MOF is a more key factor for nucleation kinetic control. MOFs with flexible linkers has comparably slower nucleation than MOFs with rigid linkers (forming PMOF-3@NJU-Bai21), and structural-flexible MOFs built by flexible linkers show the lowest nucleation and the most adaptability (affording NJU-Bai21@HHU-9). This degree of adaptability variation controls the sequence and further facilitates the synthesis of a first triple-layered core-shell MOF (PMOF-3@NJU-Bai21@HHU-9) by one-pot synthesis. The insight gained from this study will aid in the rational design and synthesis of other multi-shelled structures by one-pot synthesis and the further expansion of their applications.

The role of concentration waves in synthesizing hollow multi-shelled structures

Recently in Angewandte Chemie International Edition, Wang and co-workers presented a comprehensive study that combines a mathematical model with experiments to reveal the key role of concentration waves in the formation of hollow multi-shelled structures (HoMSs) and provides a theoretical guideline for the precise engineering of HoMSs for targeted applications. Recently in Angewandte Chemie International Edition, Wang and co-workers presented a comprehensive study that combines a mathematical model with experiments to reveal the key role of concentration waves in the formation of hollow multi-shelled structures (HoMSs) and provides a theoretical guideline for the precise engineering of HoMSs for targeted applications.

Innenrücktitelbild: A Universal Formation Mechanism of Hollow Multi‐Shelled Structures Dominated by Concentration Waves (Angew. Chem. 28/2023)

The concentration wave dominated universal formation mechanism of hollow multi-shelled structures (HoMS) is revealed by numerical simulation, as reported by Wei Ge, Dan Wang and co-workers in their Research Article (e202302621). The discovery of the physical essence behind the formation of HoMS not only flourishes the environment for HoMS synthesis, but also offers a predictive blueprint for creating dynamic HoMS by concentration waves, thereby establishing a valuable framework for future research in the realm of synthetic chemistry.

Inside Back Cover: A Universal Formation Mechanism of Hollow Multi‐Shelled Structures Dominated by Concentration Waves (Angew. Chem. Int. Ed. 28/2023)

The concentration wave dominated universal formation mechanism of hollow multi-shelled structures (HoMS) is revealed by numerical simulation, as reported by Wei Ge, Dan Wang and co-workers in their Research Article (e202302621). The discovery of the physical essence behind the formation of HoMS not only flourishes the environment for HoMS synthesis, but also offers a predictive blueprint for creating dynamic HoMS by concentration waves, thereby establishing a valuable framework for future research in the realm of synthetic chemistry.

A Universal Formation Mechanism of Hollow Multi-Shelled Structures Dominated by Concentration Waves.

Hollow multi-shelled structures (HoMS), a new family of hierarchical nano/micro-structured materials, have evoked intensive studies to discover their unique temporal-spatial ordering features. The theoretical understanding of the general synthetic methods of HoMS, i. e. the sequential templating approach (STA), makes it possible to understand, predict, and control the shell formation process. Herein, a mathematical model is established based on the experiment results, which reveal the appearance of concentration waves in the STA. The numerical simulation results not only correspond well to the experimental observations but also explain the regulation methods. Whereby, the underlying physical essence of STA is elucidated, suggesting that HoMS is the concrete representation of the concentration waves. Thereafter the formation of HoMS is not limited to the solid-state reactions through high-temperature calcination, but could be extended to synthetic systems under mild conditions.

Combing Hollow Shell Structure and Z-Scheme Heterojunction Construction for Promoting CO2 Photoreduction

CO2 photoreduction is considered one of the potential ways to achieve carbon neutralization since it uses green solar energy without introducing additional carbon sources during the process of converting CO2 to fuels. However, limited light utilization and poor charge separation often give rise to undesirable CO2 photoreduction performance. Herein, a generic approach using carbon spheres as templates to construct transition metal oxides with multishelled hollow structures is reported. The multishelled hollow structure has been proven to be efficient for improving CO2 photoreduction. Furthermore, we constructed a Z-scheme heterojunction photocatalyst (CdS/Au/ZnCrO4) through introducing CdS into a multishelled hollow ZnCrO4 sphere with Au nanoparticles as a charge transfer medium. Benefiting from the multishelled hollow structure’s induced light utilization and large surface area and Z-scheme heterojuncion promoted charge separation, a high CO production of 2.95 μmol g–1 h–1 was achieved on CdS/Au/ZnCrO4 without using any sacrificial agents, which was 18.4 times and 24.6 times higher than that of CdS and ZnCrO4. This work provides a generic method for constructing controllable multishelled hollow spheres and is expected to offer guidance for promoting CO2 photoreduction through structure regulation and heterojunction construction.

Response and Regulation of the Microenvironment Based on Hollow Structured Drug Delivery Systems

AbstractHollow structured materials with easily modifiable surfaces and enclosed interior spaces have emerged as the most promising candidates in drug delivery systems (DDS). With various functional components and inspiring cavities for creative reinvention, the response and regulation of the external and internal microenvironment of hollow structures enable their ideal drug delivery capabilities by improving drug aggregation in targeted sites and maintaining plasma concentrations at the optimal therapeutic ranges. This review begins with an in‐depth explanation of the interactions and release mechanisms of hollow structure‐based DDS, including diffusion, assembly, solvent activation, and chemical control, all of which are of great significance for the design of smart drug carriers. Next, recent advances in external microenvironment‐responsive drug delivery systems are introduced, based on various chemical signals and external field assists. Focusing on the unique view of intra‐carrier variability, the strategies for regulating the internal environment are then highlighted, including pH regulation, temperature regulation, and mechanical force regulation. Finally, this review discusses possible challenges and prospects for hollow structure‐based, particularly hollow multishelled structures intelligence‐responsive drug delivery platforms, providing valuable strategies for the development of the next generation of responsive DDS.

Hollow Nanomaterials in Advanced Drug Delivery Systems: From Single- to Multiple Shells.

Hollow-structured nanomaterials (HSNMs) have attracted increased interest in biomedical fields, owing to their excellent potential as drug delivery systems (DDSs) for clinical applications. Among HSNMs, hollow multi-shelled structures (HoMSs) exhibit properties such as high loading capacity, sequential drug release, and multi-functionalized modification and represent a new class of nanoplatforms for clinical applications. The remarkable properties of HoMS-based DDS can simultaneously satisfy and enhance DDSs for delivering small molecular drugs (e.g., antibiotics, chemotherapy drugs, and imaging agents) and macromolecular drugs (e.g., protein/peptide- and nucleic acid-based drugs). First, the latest research advances in delivering small molecular drugs are summarized and highlight the inherent advantages of HoMS-based DDSs for small molecular drug targeting, combining continuous therapeutic drug delivery and theranostics to optimize the clinical benefit. Meanwhile, the macromolecular drugs DDSs are in the initial development stage and currently offer limited delivery modes. There is a growing need to analyze the deficiency of other HSNMs and integrate the advantages of HSNMs, providing solutions for the safe, stable, and cascade delivery of macromolecular drugs to meet vast treatment requirements. Therefore, the latest advances in HoMS-based DDSs are comprehensively reviewed, mainly focusing on the characteristics, research progress by drug category, and future research prospects.

Engineering Multishelled Nanostructures Enables Stepwise Self-Degradability for Drug-Release Optimization.

The balance between degradability and drug release kinetics is a major challenge for the development of drug delivery systems. Here we develop hierarchically structured nanoparticles comprising multiple noncontact silica shells using an amorphous calcium carbonate template. The system could be degraded in a sequential fashion on account of the molecularly engineered multishelled structures. The hydrolysis rate of drug-containing cores is inversely correlated with the nanoparticle concentration due to the shielding effect of the hierarchical nanostructure and could be exploited to regulate the release kinetics. Specifically, multishelled nanospheres show a low drug release rate with high doses that increases steadily as the concentration decreases due to continuous degradation, thus stabilizing the local drug concentration for effective tumor therapy. Moreover, the nanoparticles could be eventually degraded completely, which may reduce their health risks. This kind of hierarchically structured silica-based nanoparticle could serve as a sustainable drug depot and provides a new avenue for tumor treatment.

Controllable construction of multi-shelled ZnSnO3 hollow microspheres as high-performance sensing material for acetone detection

Multi-shelled hollow structures have been drawing wide attention in various fields because of their large surface area, short diffusion path and less agglomerated configuration. Herein, ZnSnO3 hollow microspheres with controllable shell numbers have been prepared by a facile solvothermal reaction and following annealing treatment. The test results show that multi-shelled ZnSnO3 hollow microspheres exhibit excellent acetone sensing performance, which is superior than that of double-shelled samples. In particular, multi-shelled ZnSnO3 hollow microspheres not only show high responses of 105.1 and rapid response/recovery speed (1/18 s) to 100 ppm acetone, but also exhibit good repeatability, long-term stability and anti-humidity properties. Furthermore, they can easily distinguish healthy breath from simulated diabetic breath. And they still show rapid response/recovery speed in actual breath detection, which is beneficial to the achievement of real-time detection. The enhanced sensing performance has been studied systematically. Thus, multi-shelled ZnSnO3 hollow microspheres have a great potential for the diagnosis of diabetes.

PEG-Functionalized Hollow Multishelled Structures with On-Off Switch and Rate-Regulation for Controllable Antimicrobial Release.

The construction of responsive antimicrobial carriers with multifunctional and controllable release is an attractive but challenging proposition. Recently developed hollow multishelled structures (HoMSs) offers structural advantages, such as easily modifiable surfaces and mutually influenced shells. Herein, we report a novel pH-responsive antimicrobial carrier having hierarchical shells as multilevel responsive bodies using polyethylene glycol (PEG) as a gated regulator. The interaction between PEG-functionalized shells endows them with a pH-responsive switch and rate-regulator capability. These features are present in the form of rapid release of molecules wrapped in the outer shell, and controlled diffusion of antimicrobials stored in the inner shell by electrostatic interaction, resulting in a long-lasting mildew resistance for up to 71 days. The versatility of the hierarchical interactions of HoMSs will inspire the design of promising smart drug carriers.

PEG‐Functionalized Hollow Multishelled Structures with On‐Off Switch and Rate‐Regulation for Controllable Antimicrobial Release

The construction of responsive antimicrobial carriers with multifunctional and controllable release is an attractive but challenging proposition. Recently developed hollow multishelled structures (HoMSs) offers structural advantages, such as easily modifiable surfaces and mutually influenced shells. Herein, we report a novel pH-responsive antimicrobial carrier having hierarchical shells as multilevel responsive bodies using polyethylene glycol (PEG) as a gated regulator. The interaction between PEG-functionalized shells endows them with a pH-responsive switch and rate-regulator capability. These features are present in the form of rapid release of molecules wrapped in the outer shell, and controlled diffusion of antimicrobials stored in the inner shell by electrostatic interaction, resulting in a long-lasting mildew resistance for up to 71 days. The versatility of the hierarchical interactions of HoMSs will inspire the design of promising smart drug carriers.