Mesoporous N-doped graphene prepared by a soft-template method with high performance in Li-S batteries

Advances in nano-immunotherapy for hematological malignancies

Hematological malignancies (HMs) encompass a diverse group of blood neoplasms with significant morbidity and mortality. Immunotherapy has emerged as a validated and crucial treatment modality for patients with HMs. Despite notable advancements having been made in understanding and implementing immunotherapy for HMs over the past decade, several challenges persist. These challenges include immune-related adverse effects, the precise biodistribution and elimination of therapeutic antigens in vivo, immune tolerance of tumors, and immune evasion by tumor cells within the tumor microenvironment (TME). Nanotechnology, with its capacity to manipulate material properties at the nanometer scale, has the potential to tackle these obstacles and revolutionize treatment outcomes by improving various aspects such as drug targeting and stability. The convergence of nanotechnology and immunotherapy has given rise to nano-immunotherapy, a specialized branch of anti-tumor therapy. Nanotechnology has found applications in chimeric antigen receptor T cell (CAR-T) therapy, cancer vaccines, immune checkpoint inhibitors, and other immunotherapeutic strategies for HMs. In this review, we delineate recent developments and discuss current challenges in the field of nano-immunotherapy for HMs, offering novel insights into the potential of nanotechnology-based therapeutic approaches for these diseases.

Recent advances in nanoflowers: compositional and structural diversification for potential applications

In recent years, nanoscience and nanotechnology have emerged as promising fields in materials science. Spectroscopic techniques like scanning tunneling microscopy and atomic force microscopy have revolutionized the characterization, manipulation, and size control of nanomaterials, enabling the creation of diverse materials such as fullerenes, graphene, nanotubes, nanofibers, nanorods, nanowires, nanoparticles, nanocones, and nanosheets. Among these nanomaterials, there has been considerable interest in flower-shaped hierarchical 3D nanostructures, known as nanoflowers. These structures offer advantages like a higher surface-to-volume ratio compared to spherical nanoparticles, cost-effectiveness, and environmentally friendly preparation methods. Researchers have explored various applications of 3D nanostructures with unique morphologies derived from different nanoflowers. The nanoflowers are classified as organic, inorganic and hybrid, and the hybrids are a combination thereof, and most research studies of the nanoflowers have been focused on biomedical applications. Intriguingly, among them, inorganic nanoflowers have been studied extensively in various areas, such as electro, photo, and chemical catalysis, sensors, supercapacitors, and batteries, owing to their high catalytic efficiency and optical characteristics, which arise from their composition, crystal structure, and local surface plasmon resonance (LSPR). Despite the significant interest in inorganic nanoflowers, comprehensive reviews on this topic have been scarce until now. This is the first review focusing on inorganic nanoflowers for applications in electro, photo, and chemical catalysts, sensors, supercapacitors, and batteries. Since the early 2000s, more than 350 papers have been published on this topic with many ongoing research projects. This review categorizes the reported inorganic nanoflowers into four groups based on their composition and structure: metal, metal oxide, alloy, and other nanoflowers, including silica, metal-metal oxide, core-shell, doped, coated, nitride, sulfide, phosphide, selenide, and telluride nanoflowers. The review thoroughly discusses the preparation methods, conditions for morphology and size control, mechanisms, characteristics, and potential applications of these nanoflowers, aiming to facilitate future research and promote highly effective and synergistic applications in various fields.

Peptide-metal nanohybrids (PMN): Promising entities for combating neurological maladies

Nanotherapeutics are gaining traction in the modern scenario because of their unique and distinct properties which separate them from macro materials. Among the nanoparticles, metal NPs (MNPs) have gained importance due to their distinct physicochemical and biological characteristics. Peptides also exhibit several important functions in humans. Different peptides have received approval as pharmaceuticals, and clinical trials have been commenced for several peptides. Peptides are also used as targeting ligands. Considering all the advantages offered by these two entities, the conjugation of MNPs with peptides has emerged as a potential strategy for achieving successful targeting, diagnosis, and therapy of various neurological pathologies.

A review of nanoparticle synthesis and application in the suppression of diseases in fruits and vegetables

Fruits and vegetables are an integral part of our diet attributed to their appealing taste, flavor, and health-promoting characteristics. However, due to their high-water activity, they are susceptible to microbial spoilage and diseases at any step in the food supply chain, from pre-harvest treatment to post-harvest storage and transportation. As a result, food researchers and engineers are developing innovative technologies that can be used to reduce the loss of fruits and vegetables on-farm and during postharvest processing. The purpose of this study was to gather and discuss the scientific data on the disease-suppressive activity of nanoparticles against plant pathogens. The progress and limitations of innovative approaches for improving nanoparticles' efficiency and dependability have been studied to develop effective substitutes for synthetic chemical fungicides and pesticides, in managing disease in fruits and vegetables. The findings of this study strongly suggests that nanotechnology has the required ability for disease suppression in fruits and vegetables. Applications of specific nanoparticles under specified conditions can enhance nutrition delivery to plants, provide better antibacterial and disease suppression activity. Nanoparticles can also lessen the quantity of agrichemicals/metals released into the environment as compared to standard formulations, which is one of the most impressive advances.

Green and Scalable Template-Free Strategy to Fabricate Honeycomb-Like Interconnected Porous Micro-Sized Layered Sb for High-Performance Potassium Storage

The tremendous volume change and severe pulverization of micro-sized Sb anode generate no stable capacity in potassium-ion batteries (PIBs). The honeycomb-like porous structure provides free spaces to accommodate its volume expansion and offers efficient ion transport, yet complex synthesis and low yield limits its large-scale application. Here, a green, scalable template-free method for designing a 3D honeycomb-like interconnected porous micro-sized Sb (porous-Sb) is proposed. Its honeycomb-like porous formation mechanism is also verified. Under hydrothermal conditions, Sb reacts with water and dissolved oxygen in water, undergoing non-homogeneous and continuous corrosion at grain boundaries, and producing soluble H₂ Sb₂ O₆ (H₂ O), which regulates the porous structure of Sb by controlling reaction time. Benefiting from its porous structure and micron size, porous-Sb anode displays large gravimetric and volumetric capacities with 655.5 mAh g^-1 and 2,001.9 mAh cm^-3 at 0.05 A g^-1 and superior rate performance of 441.9 mAh g^-1 at 2.0 A g^-1 in PIBs. Furthermore, ex situ characterization and kinetic analysis uncover the small volume expansion and fast K⁺ reaction kinetics of porous Sb during potassiation/depotassiation, originating from its large electrolyte contact area and internal expansion mechanism. It verifies a green, scalable template-free strategy to construct honeycomb-like porous metals for energy storage and conversion.

Density functional theory study of active sites on nitrogen-doped graphene for oxygen reduction reaction

Oxygen reduction reaction (ORR) remains challenging due to its complexity and slow kinetics. In particular, Pt-based catalysts which possess outstanding ORR activity are limited in application with high cost and ease of poisoning. In recent years, nitrogen-doped graphene has been widely studied as a potential ORR catalyst for replacing Pt. However, the vague understanding of the reaction mechanism and active sites limits the potential ORR activity of nitrogen-doped graphene materials. Herein, density functional theory is used to study the reaction mechanism and active sites of nitrogen-doped graphene for ORR at the atomic level, focusing on explaining the important role of nitrogen species on ORR. The results reveal that graphitic N (GrN) doping is beneficial to improve the ORR performance of graphene, and dual-GrN-doped graphene can demonstrate the highest catalytic properties with the lowest barriers of ORR. These results provide a theoretical guide for designing catalysts with ideal ORR property, which puts forward a new approach to conceive brilliant catalysts related to energy conversion and environmental catalysis.

Engineering Oversaturated Fe-N5 Multifunctional Catalytic Sites for Durable Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries are regarded as a promising next-generation system for advanced energy storage owing to a high theoretical energy density of 2600 Wh kg^-1 . However, the practical implementation of Li-S batteries has been thwarted by the detrimental shuttling behavior of polysulfides, and the sluggish kinetics in electrochemical processes. Herein, a novel single atom (SA) catalyst with oversaturated Fe-N₅ coordination structure (Fe-N₅ -C) is precisely synthesized by an absorption-pyrolysis strategy and introduced as an effective sulfur host material. The experimental characterizations and theoretical calculations reveal synergism between atomically dispersed Fe-N₅ active sites and the unique carbon support. The results exhibit that the sulfur composite cathode built on the Fe-N₅ -C can not only adsorb polysulfides via chemical interaction, but also boost the redox reaction kinetics, thus mitigating the shuttle effect. Meanwhile, the robust three-dimensional nitrogen doped carbon nanofiber with large surface area, and high porosity enables strong physical confinement and fast electron/ion transfer process. Attributed to such unique features, Li-S batteries with S/Fe-N₅ -C composite cathode realize outstanding cyclability and rate capability, as well as high areal capacities under raised sulfur loading, which demonstrates great potential in developing advanced Li-S batteries.

Nickel-Embedded Carbon Materials Derived from Wheat Flour for Li-Ion Storage

The biomass-based carbons anode materials have drawn significant attention because of admirable electrochemical performance on account of their nontoxicity and abundance resources. Herein, a novel type of nickel-embedded carbon material (nickel@carbon) is prepared by carbonizing the dough which is synthesized by mixing wheat flour and nickel nitrate as anode material in lithium-ion batteries. In the course of the carbonization process, the wheat flour is employed as a carbon precursor, while the nickel nitrate is introduced as both a graphitization catalyst and a pore-forming agent. The in situ formed Ni nanoparticles play a crucial role in catalyzing graphitization and regulating the carbon nanocrystalline structure. Mainly owing to the graphite-like carbon microcrystalline structure and the microporosity structure, the NC-600 sample exhibits a favorable reversible capacity (700.8 mAh g⁻¹ at 0.1 A g⁻¹ after 200 cycles), good rate performance (51.3 mAh g⁻¹ at 20 A g⁻¹), and long-cycling durability (257.25 mAh g⁻¹ at 1 A g⁻¹ after 800 cycles). Hence, this work proposes a promising inexpensive and highly sustainable biomass-based carbon anode material with superior electrochemical properties in LIBs.

Ultrafine nanosulfur particles sandwiched in little oxygen-functionalized graphene layers as cathodes for high rate and long-life lithium-sulfur batteries

Although lithium-sulfur batteries are one of the promising candidates for next-generation energy storage systems, the practical applications are still hampered by the poor cycle life, which can be attributed to the insulating properties of sulfur and the shuttle effect of electrochemical intermediate polysulfides. To address these problems, we synthesize sandwich-like composites which consist of ultrafine nanosulfur particles enveloped by little oxygen-functionalized graphene layers (F-GS@S). In this structure, the little oxygen-functionalized graphene backbone can not only accelerate the redox kinetics of sulfur species, but also eliminate the shuttle effect of polysulfides by strong chemical interaction. Moreover, the sandwich confinement structures can further inhibit the dissolution of polysulfides by physical restraint and accommodate the volume contraction/expansion of sulfur during cycling. As a result, the F-GS@S composites used as cathodes for lithium-sulfur batteries display a superior rate capability with the high capacities of 1208 mAh g^-1 at 0.1 C and 601.7 mAh g^-1 at 2 C and high cycling stability with a capacity retention of 70.5% after 500 cycles at 2 C. In situ characterizations and real-time monitoring experiments during the charge-discharge process are carried out to elucidate the reaction mechanism of the F-GS@S composites as cathodes for high rate and long-life lithium-sulfur batteries.

Naturally derived honeycomb-like N,S-codoped hierarchical porous carbon with MS2 (M = Co, Ni) decoration for high-performance Li-S battery

Even though lithium-sulfur batteries have appealing advantages including a high theoretical capacity and energy density, their commercial implementation has been seriously hindered by some notorious reasons, particularly the severe shuttling effect, the insulating nature of sulfur, the large volumetric variation during cycling and the sluggish redox reaction kinetics. To tackle these issues, a biomass (ginkgo-nut) derived N,S-codoped porous carbon (GC) with an interconnected honeycomb-like hierarchical structure is synthesized by a templated carbonization method, followed by hydrothermal growth of transition metal sulfide MS2 (M = Co, Ni) nanocrystals, giving rise to a hybrid 3D electrocatalyst. The unique structure constructed by N,S-codoping can expose more active sites and polar surfaces to physically confine and chemically adsorb polysulfides. Meanwhile, the embedded MS2 polyhedral-like nanoparticles further enhance the interaction with polysulfides and improve conversion and redox kinetics of polysulfides. Remarkably, with 80 wt% sulfur loading (∼2.5 mg cm-2), GC-CoS2 exhibits a reversible capacity of 988.8 mA h g-1 after 500 cycles at 0.1 C and an excellent capacity of 610.3 mA h g-1 after 1000 cycles at 2 C, outperforming bare GC and GC-NiS2. Compared with the electrochemical performances of the representative reported biomass-derived sulfur host for Li-S batteries, evidently, both the discharge capacity and cycling stability of our GC-CoS2 sample are superior. Density functional theory (DFT) calculation results suggest that CoS2 exhibits a higher binding energy towards lithium polysulfides and a lower energy barrier for Li+ diffusion on the surface compared to the NiS2 counterpart, suggesting that CoS2 is a better choice for lithium-sulfur batteries than NiS2. This work provides a new avenue to rationally design a carbonaceous catalyst host for high-performance lithium-sulfur batteries.

Unique Flexible NiFe2O4@S/rGO-CNT Electrode via the Synergistic Adsorption/Electrocatalysis Effect toward High-Performance Lithium-Sulfur Batteries

A unique flexible NiFe₂O₄ hollow sphere@S/rGO-CNT (NiFe₂O₄@S/C) cathode was rationally designed and synthesized to tackle the issues of lithium-sulfur batteries. In this strategy, the introduced rGO and CNTs offer a flexible and conductive skeleton to facilitate the transport of electrons and/or ions and a physical barrier to confine polysulfides. Furthermore, as an efficient sulfur host, NiFe₂O₄ hollow spheres can further absorb the soluble polysulfides by strong chemical interaction due to their intrinsic polarity and also serve as a catalyst to promote the redox kinetics of polysulfide conversion. Benefiting from the synergism of the physical confinement, polar chemical adsorption, and catalytic conversion, the as-prepared flexible NiFe₂O₄@S/C electrode delivers a high initial capacity of 1193 mAh g^-1 at 100 mA g^-1 and excellent long-term cycling stability up to 500 cycles with a low decay rate of 0.059% per cycle at 500 mA g^-1.