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Highlights An air-breathing chemical self-charge concept of oxygen-enriched carbon cathode. The oxygen-enriched carbon material with abundant catechol groups. Rapid air-oxidation chemical self-charge of catechol groups. Abstract The self-charging concept has drawn considerable attention due to its excellent ability to achieve environmental energy harvesting, conversion and storage without an external power supply. However, most self-charging designs assembled by multiple energy harvesting, conversion and storage materials increase the energy transfer loss; the environmental energy supply is generally limited by climate and meteorological conditions, hindering the potential application of these self-powered devices to be available at all times. Based on aerobic autoxidation of catechol, which is similar to the electrochemical oxidation of the catechol groups on the carbon materials under an electrical charge, we proposed an air-breathing chemical self-charge concept based on the aerobic autoxidation of catechol groups on oxygen-enriched carbon materials to ortho-quinone groups. Energy harvesting, conversion and storage functions could be integrated on a single carbon material to avoid the energy transfer loss among the different materials. Moreover, the assembled Cu/oxygen-enriched carbon battery confirmed the feasibility of the air-oxidation self-charging/electrical discharging mechanism for potential applications. This air-breathing chemical self-charge concept could facilitate the exploration of high-efficiency sustainable air self-charging devices.

Abstract Magnetic nanomaterials have played a crucial role in promoting the application of nanotechnology in the biomedical field. Although conventional magnetic nanomaterials such as iron oxide nanoparticles (NPs) are used as biosensors, drug delivery vehicles, diagnostic and treatment agents for several diseases, the persistent pursuit of high‐performance technologies has prompted researchers to continuously develop new types of magnetic nanomaterials such as iron carbide NPs. Considering their potential application in biomedicine, magnetic NPs responsive to exogenous or endogenous stimuli are developed, thereby enhancing their applicability in more complex versatile scenarios. In this review, the synthesis and surface modification of magnetic NPs are focused, particularly iron carbide NPs. Subsequently, exogenous and endogenous stimuli‐responsive magnetic NP‐based theranostic platforms are introduced, particularly focusing on nanozyme‐based technologies and magnetic NP‐mediated immunotherapy, which are emerging stimuli‐responsive treatments. Finally, the challenges and perspectives of magnetic NPs to accelerate future research in this field are discussed.

Abstract Two-dimensional arrays of magnetically coupled nanomagnets provide a mesoscopic platform for exploring collective phenomena as well as realizing a broad range of spintronic devices. In particular, the magnetic coupling plays a critical role in determining the nature of the cooperative behavior and providing new functionalities in nanomagnet-based devices. Here, we create coupled Ising-like nanomagnets in which the coupling between adjacent nanomagnetic regions can be reversibly converted between parallel and antiparallel through solid-state ionic gating. This is achieved with the voltage-control of the magnetic anisotropy in a nanosized region where the symmetric exchange interaction favors parallel alignment and the antisymmetric exchange interaction, namely the Dzyaloshinskii-Moriya interaction, favors antiparallel alignment of the nanomagnet magnetizations. Applying this concept to a two-dimensional lattice, we demonstrate a voltage-controlled phase transition in artificial spin ices. Furthermore, we achieve an addressable control of the individual couplings and realize an electrically programmable Ising network, which opens up new avenues to design nanomagnet-based logic devices and neuromorphic computers.

2D nonlayered materials exhibit interesting properties for catalysis, nanoelectronics and spintronics applications, but their growth is still challenging. Here, the authors report a theoretical model and an experimental strategy to synthesize various 2D nonlayered transition metal oxides with room-temperature magnetic properties.

Potassium-ion batteries (PIBs) are potential “Beyond Li-ion Batteries” candidates for their resource advantage and low standard electrode potential. To date, the research on PIBs is in its early stages, the most urgent task is to develop high-performance electrode materials and reveal their potassium storage mechanism. For PIBs anode materials, carbon with tunable microstructure, excellent electrochemical activity, nontoxicity and low price is considered as one of the most promising anode materials for commercialization. Although some breakthrough works have emerged, the overall electrochemical performance of the reported carbon anode is still far away from practical application. Herein, we carry out a comprehensive overview of PIBs carbon anode in terms of three aspects of rational design of structure, performance evaluation criteria and characterization of potassium storage mechanism. First, the regulation mechanism of key structural features of carbon anode on its potassium storage performance and the representative structural regulation strategies are introduced. Then, in view of the undefined performance evaluation criteria of PIBs carbon anode, a reference principle for evaluating the potassium storage performance of carbon anode is proposed. Finally, the advanced characterization techniques for the potassium storage mechanism of carbon anode are summarize. This review aims to provide guidance for the development of practical PIBs anode.

Abstract Sodium‐ion batteries (SIBs) are potential candidates for the replacement of lithium‐ion batteries to meet the increasing demands of electrical storage systems due to the low cost and high abundance of sodium. Sodium superionic conductor (NASICON) structured materials have attracted enormous interest in recent years as electrode materials for safer and long‐term performance of SIBs for electric energy storage smart grids. These materials have a three‐dimensional robust framework, high redox potential, thermal stability, and a fast Na+‐ion diffusion mechanism. However, NASICON has low intrinsic electronic conductivity, which limits the electrochemical performance. This review describes the structural features of NASICONs to illustrate the ion storage mechanism and electrochemical performance of SIBs. Details of the NASICON crystal structure, the affiliated Na+‐ion diffusion mechanism, morphology, and electrochemical performance of these materials in sodium‐ion half‐cells as well as full cells are described. In addition to the application as electrode materials, the use of NASICONs as solid electrolytes is also elaborated in solid‐state SIBs. Based on these aspects, we have provided more perspectives in terms of the commercialization of SIBs and strategies to overcome the limitations of NASICONs. Hence, this review is expected to provide the researchers of energy storage with an in‐depth understanding of NASICON materials with the knowledge of structural features, which will provide a new avenue on the practicality of SIBs.

Abstract A major bottleneck underlying nanomaterial‐based tumor therapy lies in complex biological environment and physiological barriers. Micro/nanorobots with the features of self‐propulsion and controllable navigation have gradually become a research hotspot in the tumor therapeutic community, exhibiting their advantages in efficient cargo loading, controllable cargo delivery, stimuli‐triggered cargo release, deeper tumor tissue penetration, and enhanced cargo accumulation in tumor tissue. In this review, the self‐propulsion and controllable navigation are introduced as two major properties of micro/nanorobots, in which micro/nanorobots are propelled by chemical reactions, physical fields, and biological systems and could be navigated by chemotaxis, remote magnetic guidance, and light. Then, the recent advances of micro/nanorobots for chemotherapy, immunotherapy, photothermal therapy, photodynamic therapy, chemodynamic therapy, and multimodal tumor therapy would be discussed. Finally, the perspective and challenges are also mentioned. It is expected that this review gives an insight into intelligent micro/nanorobots for improved tumor therapy, aiming for more extensive and in‐depth investigations, and final applications in the clinic.

Since their discovery in 2011, the two-dimensional transition-metal carbides, nitrides, and carbonitrides known as MXenes have attracted considerable attention due to their metallic conductivity, mechanical properties, and hydrophilicity, which are closely related to their rich surface terminations. As a result, numerous novel synthesis strategies have been explored and new MXenes have been developed. Some have been applied in the field of energy storage, typically lithium–sulfur batteries (LSBs). This review summarizes recent advances in MXenes for LSBs. We first introduce the structural characterization of these materials, then provide detailed summaries of synthetic methods. Next, we give a comprehensive overview of research progress on MXenes for the cathodes, separators, and anodes in LSBs. Finally, we address challenges and offer perspectives on future directions for research. We hope this review will help researchers gain insight into multifunctional MXenes and their comprehensive applications in LSBs.

Chiral magnetic vortex has shown great potential for high-density magnetic storage, modern telecommunication and computation devices, thanks to its topological stability and rich dynamic behaviours. Particularly, the synchronization of magnetic vortex nano-oscillators leads to the emergence of fascinating collective phenomena used for microwave generator and neuromorphic computing. In this work, by means of micromagnetic simulations, we create stable chiral magnetic vortices by exploiting the chiral coupling principle and study the gyrotropic motion of the vortex core under spin-transfer torques. The gyrotropic oscillation frequency can be tuned by injecting spin-polarised current as well as the change of the magnetic anisotropy in the vortex area, resulting from the modification of the vortex confine potential and the size of the vortex core. Two vortex nano-oscillators can be synchronized wherein the synchronization state can be modulated by the spin-polarised current and the magnetic anisotropy. Moreover, we demonstrate that the magnetic anisotropy can modify the synchronization patterns when integrating six vortices into an oscillator network, making it potentially serve as an oscillator-based neural network. Our work provides a new route to constructing a flexible oscillator network for neuromorphic computing hardware.

Magnetic nanoparticles(NPs) are characterized by a rich variety of properties. Because of their excellent physical and chemical properties, they have come to the fore in biomedicine and other fields. The magnetic NPs were extensively studied in magnetic separation of cells, targeted drug delivery, tumor hyperthermia, chemo-photothermal therapy, magnetic resonance imaging (MRI) and other biomedical fields. Magnetic NPs are increasingly used in magnetic resonance imaging (MRI) based on their inherent magnetic targeting, superparamagnetic enzyme-like catalytic properties and nanoscale size. Poly(lactic-co-glycolic acid) (PLGA) is a promising biodegradable material approved by FDA and EU for drug delivery. Currently, PLGA-based magnetic nano-drug delivery systems have attracted the attention of researchers. Herein, we achieved the effective encapsulation of sized-controlled polyethylene glycol-3,4-dihydroxy benzyl-amine-coated superparamagnetic iron oxide nanoparticles (SPIO NPs) and euphorbiasteroid into PLGA nanospheres via a modified multiple emulsion solvent evaporation method (W1/O2/W2). NPs with narrow size distribution and acceptable magnetic properties were developed that are very useful for applications involving cancer therapy and MRI. Furthermore, SPIO-PLGA NPs enhanced the MRI T2 relaxation properties of tumor sites.The prepared SPIO NPs and magnetic PLGA nanospheres can be promising magnetic drug delivery systems for tumor theranostics. This study has successfully constructed a tumor-targeting and magnetic-targeting smart nanocarrier with enhanced permeability and retention, multimodal anti-cancer therapeutics and biodegradability, which could be a hopeful candidate for anti-tumor therapy in the future.

To broaden the scope of van der Waals 2D magnets, we report the synthesis and magnetism of covalent 2D magnetic Cr2Te3 with a thickness down to one-unit-cell. The 2D Cr2Te3 crystals exhibit robust ferromagnetism with a Curie temperature of 180 K, a large perpendicular anisotropy of 7 × 105 J m−3, and a high coercivity of ∼4.6 kG at 20 K. First principles calculations further show a transition from canted to collinear ferromagnetism, a transition from perpendicular to in-plane anisotropy, and emergent half-metallic behavior in atomically-thin Cr2Te3, suggesting its potential application for injecting carriers with high spin polarization into spintronic devices.

A mixture of nitrogen species in carbon materials typically hinders the precise identification of electrochemically active nitrogen configurations for specific reactions. Here the authors show single-site pyrrolic-nitrogen-doped sp 2-hybridized carbon materials and their pseudocapacitive properties.

Combination therapy has shown its promise in the clinic for enhancing the efficacy of tumor treatment. However, the dose control of multiple drugs and their non-overlapping toxicity from different drugs are still great challenge. In this work, a single model drug, paclitaxel (PTX), is used to realize combination therapy and solve the problems mentioned above. Either PTX or its triphenylphosphine derivative (TPTX) is encapsulated in galactose-modified liposomes (GLips) to obtain GLips-P or GLips-TP, which are simply mixed in different ratios to finely control the proportion of PTX and TPTX. These mixed liposomes, GLips-P/TP, feature a cascade target delivery of PTX, from tissue to cell, and then to organelle. PTX plays a primary role to cause the cytotoxicity by microtubule bindings in cytoplasm, while TPTX is proved to increase the intracellular levels of caspase-3 and caspase-9 that cause apoptosis via a mitochondria-mediated pathway. Notably, GLips-P/TP 3:1 exhibited the significant drug synergy in both cytotoxicity assay of HepG2 cells and the treatment efficacy in Heps xenograft ICR mouse models. This work not only demonstrates the great promise of a cascade targeting delivery for precise tumor treatment, but also offers a novel platform to design combinatory therapy systems using a single drug. KEY WORDS: Combin chemotherapy, Single drug, Paclitaxel, Microtubules, Mitochondria, Cytotoxicity

Nanoparticles that can change shape have attracted attention for improved circulation and tumor penetration. Here, the authors report on a size changeable nanoparticle that responds to near-infrared light and can be used for photothermal therapy, photodynamic therapy, and drug delivery applications.

Abstract Substitutional doping of layered transition metal dichalcogenides (TMDs) has been proved to be an effective route to alter their intrinsic properties and achieve tunable bandgap, electrical conductivity and magnetism, thus greatly broadening their applications. However, achieving valid substitutional doping of TMDs remains a great challenge to date. Herein, a distinctive molten‐salt‐assisted chemical vapor deposition (MACVD) method is developed to match the volatilization of the dopants perfectly with the growth process of monolayer MoS2, realizing the substitutional doping of transition metal Fe, Co, and Mn. This doping strategy effectively alters the electronic structure and phononic properties of the pristine MoS2. In addition, a temperature‐dependent Raman spectrum is employed to explore the effect of dopants on the lattice dynamics and first‐order temperature coefficient of monolayer MoS2, and this doping effect is illustrated in depth combined with the theoretical calculation. This work provides an intriguing and powerful doping strategy for TMDs through employing molten salt in the CVD system, paving the way for exploring new properties of 2D TMDs and extending their applications into spintronics, catalytic chemistry and photoelectric devices.

The shuttle effect hinders the practical application of lithium-sulfur (Li-S) batteries due to the poor affinity between a substrate and Li polysulfides (LiPSs) and the sluggish transition of soluble LiPSs to insoluble Li2S or elemental S. Here, we report that Ni hexatomic clusters embedded in a nitrogen-doped three-dimensional (3D) graphene framework (Ni-N/G) possess stronger interaction with soluble polysulfides than that with insoluble polysulfides. The synthetic electrocatalyst deployed in the sulfur cathode plays a multifunctional role: (i) selectively adsorbing the polysulfides dissolved in the electrolyte, (ii) expediting the sluggish liquid-solid phase transformations at the active sites as electrocatalysts, and (iii) accelerating the kinetics of the electrochemical reaction of multielectron sulfur, thereby inhibiting the dissolution of LiPSs. The constructed S@Ni-N/G cathode delivers an areal capacity of 9.43 mAh cm-2 at 0.1 C at S loading of 6.8 mg cm-2, and it exhibits a gravimetric capacity of 1104 mAh g-1 with a capacity fading rate of 0.045% per cycle over 50 cycles at 0.2 C at S loading of 2.0 mg cm-2. This work opens a rational approach to achieve the selective adsorption and expediting of polysulfide transition for the performance enhancement of Li-S batteries.

Abstract The desire for practical utilization of rechargeable lithium batteries with high energy density has motivated attempts to develop new electrode materials and battery systems. Here, without additional binders we present a simple vacuum filtration method to synthesize nitrogen and sulfur codoped graphene (N,S-G) blocking layer, which is ultra-lightweight, conductive, and free standing. When the N,S-G membrane was inserted between the catholyte and separator, the lithium–selenium (Li–Se) batteries exhibited a high reversible discharge capacity of 330.7 mAh g−1 at 1 C (1 C = 675 mA g−1) after 500 cycles and high rate performance (over 310 mAh g−1 at 4 C) even at an active material loading as high as ~ 5 mg cm−2. This excellent performance can be ascribed to homogenous dispersion of the liquid active material in the electrode, good Li+-ion conductivity, fast electronic transport in the conductive graphene framework, and strong chemical confinement of polyselenides by nitrogen and sulfur atoms. More importantly, it is a promising strategy for enhancing the energy density of Li–Se batteries by using the catholyte with a lightweight heteroatom doping carbon matrix.

Lithium‐based batteries possessing energy densities much higher than those of the conventional batteries belong to the most promising class of future energy devices. However, there are some fundamental issues related to their electrodes which are big roadblocks in their applications to electric vehicles (EVs). Nanochemistry has advantageous roles to overcome these problems by defining new nanostructures of electrode materials. This review article will highlight the challenges associated with these chemistries both to bring high performance and longevity upon considering the working principles of the various types of lithium‐based (Li‐ion, Li‐air and Li‐S) batteries. Further, the review discusses the advantages and challenges of nanomaterials in nanostructured electrodes of lithium‐based batteries, concerns with lithium metal anode and the recent advancement in electrode nanostructures.