Highly concentrated electrolytes have been found to improve the cycle life and Coulombic efficiency of lithium metal anodes, as well as to suppress dendrite growth. However, the mechanism for these improvements is not well understood. Partly, this can be linked to the difficulty of accurately characterizing the solid electrolyte interphase (SEI), known to play an important role for anode stability and stripping/plating efficiency. Herein, in situ neutron reflectometry is used to obtain information about SEI formation in a highly concentrated ether-based electrolyte. With neutron reflectometry, the thickness, scattering length density (SLD), and roughness of the SEI layer formed on a Cu working electrode are nondestructively probed. The reflectivity data point to the formation of a thin (5 nm) SEI in the highly concentrated electrolyte (salt:solvent ratio 1:2.2), while a considerably thicker (13 nm) SEI is formed in an electrolyte at lower salt concentration (salt:solvent ratio 1:13.7). Further, the SEI formed in the electrolyte with high salt concentration has a higher SLD, suggesting that the chemical composition of the SEI changes. The results from neutron reflectometry correlate well with the electrochemical data from SEI formation.

As a thriving family of 2D nanomaterials, early transition metal carbides and carbonitrides (MXenes) are regarded as promising candidates in various applications. To enhance the mechanical robustness and environmental stability of MXenes, research on their polymer-based nanocomposites with improved oxidation and damage tolerance has attracted increasing attention. As a reinforcing and functional filler, MXenes can also endow polymer with desired thermal/electrical properties. Compared to the powder-based direct dispersion, assembling MXene nanosheets into MXene macrostructures (MMs) is proven as an effective strategy to unite with polymer. In particular, performance of the nanocomposites can be readily optimized by manipulating the structure of MMs and their interactions with polymer. In this Review, recent research progress on the MMs/polymer nanocomposites is summarized to provide a systematic understanding of the relationships among structures, fabrication techniques, and performance. Beyond diverse exfoliation methods for synthesizing MXene flakes, special attention is given to the assembly routes to construct mechanically robust macrostructures and hybrid techniques to build various MMs/polymer nanocomposites. Then, their applications in several areas of fundamental research and practical application are discussed, including heat/electrical conduction, electromagnetic shielding, and flexible devices. Finally, the challenges and perspectives are summarized to guide the future exploration for multifunctional MMs/polymer nanocomposites.

A novel recycling process of the conductive agent in spent lithium iron phosphate batteries is demonstrated. Wet chemistry is applied in recovering lithium and iron phosphate, and the filter residue is calcined with a small amount of recovered iron phosphate in N2 at 900 °C to form a FeNP-codoped carbon catalyst, which exhibits a low half-wave potential and excellent durability for oxygen reduction. When applied in a rechargeable Zn–air battery, the power density can reach 80 mW cm−2.

The growth of Li dendrites in a solid electrolyte is commonly idealized by a pressure-filled crack. Recent observations in both garnet and sulfide electrolytes show that sparsely filled cracks exist prior to shorting of the cell, thereby invalidating this assumption. Herein, a variational principle that uses the Onsager formalism to couple Li deposition into the crack, elastic deformation of the electrolyte, and cracking of the electrolyte with the electrochemical driving forces and dissipation within the electrolyte and interfaces is developed. Consistent with observations, it is shown that Li ingress and cracking occur together for garnet electrolytes, but the cracks are sparsely filled. This sparse filling is a direct consequence of the mismatch between the elastic opening of the cracks and the deposition of Li into the cracks across the crack flanks. An increase in the resistance of Li ingress into the tips of Li filaments results in crack propagating ahead of the Li filaments, as observed for sulfide electrolytes. In such cases, the cracks are largely dry. The results provide a framework to model Li ingress into solid electrolytes and explain why the observations are qualitatively so different from dendrites in liquid electrolytes.

High-strength and high-toughness bio-based fibers attract broad interest in biomechanical applications. Herein, strong and tough organic–inorganic regenerated silk fibroin/hydroxyapatite (RSF/HAP) hybrid fibers are prepared using a single-channel microfluidic device. Calcium phosphate oligomers (CPOs) dispersed in the RSF matrix first grow into spherical amorphous calcium phosphates (ACPs), which then crystallize into needle-like HAPs under a humidity condition, mimicking the biomineralization in collagen bundles. HAPs are better aligned along the RSF/HAP fiber direction after poststretching, forming a highly ordered and densely packed microstructure within the fiber and thus facilitating highly dense noncovalent interactions between rigid inorganic HAP nanocrystals and flexible organic RSF matrix. The highly dense noncovalent interactions endow the organic–inorganic hybrid fibers with superior mechanical properties and twisted RSF/HAP fiber bundles demonstrate a remarkable tensile strength of 778 MPa, a high Young's modulus of 17.8 GPa, a large tensile strain of 19.9%, and an excellent toughness of 121 MJ m−3 after proper twisting treatments. RSF/HAP hybrid fibers also show good performances against static loading, dynamic impact, and extreme cold condition and they can maintain their mechanical properties down to −50 °C. Therefore, the fibers are strong and tough and the strategy is facile and efficient.

Metal–organic gels (MOG) as new types of soft materials have shown promising applications in various fields such as chemosensors, environmental remediation, and gas adsorption/separation, owing to their high porosity, low density, and high surface area. However, the application of MOG materials in energy electrocatalysis and the active components made from them are rarely perceived. Herein, a new electrochemistry-driven reconstruction strategy to synthesize the NiOOH/FeOOH heterostructure from MOG materials is reported. The reconstructed NiOOH/FeOOH exhibits superior oxygen evolution reaction activity and excellent stability, owing to the synergistic effect of bimetallic centers, the abundant interface between NiOOH and FeOOH, and the plentiful defects. Impressively, the activated Re–FeNi–MOG-4 electrocatalyst displays remarkable catalytic activity with a low overpotential of 220 mV at a current density of 10 mA cm−2 and a small Tafel slope of 48 mV dec−1 in alkaline electrolyte, outperforming most recently reported electrocatalysts. Herein, a facile and effective electrochemical reconstruction engineering of pre-catalysts is provided and the evolution of self-reconstruction of MOG materials for accelerating the kinetics of the electrocatalytic process is highlighted.

The equine hoof wall has a unique hierarchical structure that allows it to survive high-impact scenarios. Previous authors have explored the compressive, viscoelastic, and fracture control properties of the hoof wall and suggested that this complex structure plays a vital role in the hoof's behavior. However, the link between the structure and the behavior of the hoof wall has been made primarily with the use of post-fracture analysis. Here, periodic microcomputed tomography scans are used to observe the temporal behavior of the hoof's meso and microstructures during compression, fracture, and relaxation. These results shed light on the structural anisotropy of the hoof wall and how its hollow tubules behave when compressed in different directions, at different hydration levels, and in various locations within the hoof wall. The behavior of tubule bridges during compression is also reported for the first time. This study elucidates several fracture phenomena, including the way cracks are deflected at tubule interfaces and tubule bridging, tubule arresting, and fiber bridging. Finally, relaxation tests are used to show how the tubule cavities can regain their shape after compression.

Reasonable regulation of iodine redox has gradually shown potential as a desirable cathodic reaction in zinc-based batteries, but suffers from poor cyclic reversibility caused by uncontrollable side reactions. Also, the irregular growth of dendrites and unavoidable occurrences of hydrogen evolution reaction in H2O-rich environment have become permanent topics in anodic zinc. Herein, a cross-linked gel based on carboxymethyl chitosan is proposed and serves as an artificial electrolyte interphase for zinc anode (marked as Zn-CMCS). Such a coating formed by crosslinking among a monodentate carboxyl group, a hydroxyl, an amino, and Zn2+ from adding solution closely adheres on the surface of the zinc foil with toughness, ductility, and ideal electrochemical kinetics. Additionally, its homogenized surface charge distribution provides a “flexible” substrate for zinc plating/stripping, resulting in a flat real-time interface. While introducing I−/I0 conversion by matching adsorptive activated carbon on carbon fiber cloth (AC-CFC) as cathode, the internal space restricted by CMCS gel enables the assembled Zn-CMCS/AC-CFC battery to exhibit a greatly improved reversibility under long-cycling condition within 28 000 cycles (measured for more than 2 years) in a narrow operating voltage range of 0.23 V.

A simple strategy to fabricate Cu single atoms (SAs) layer-intercalated MoS2 only by stirring Cu metals with MoS2 nanosheets solution at room temperature is reported. An ultra-high concentration (Cu: Mo = 98 at%) of Cu SAs is achieved and the intercalated Cu atoms strongly enhance the stability of the thermodynamically unstable 1T-phase dominant MoS2. Notably, the as-synthesized MoS2/Cu-SAs exhibit a surprisingly high proportion of the metallic phase (64%) even after annealing at 800 °C in 5% H2/Ar foaming gas, indicating extraordinary thermostability of the Cu intercalated 1 T-MoS2. In addition to, the as-prepared MoS2/SAs exhibit outstanding catalytic performance owing to the improved electrical conductivity and the highly active unsaturated Cu SAs. This strategy is confirmed as a universal method for producing SAs of other metals and other 2D nanosheets can also be used as the host for SAs intercalation other than MoS2. This study may provide an effective strategy to fabricate facile and low-cost SAs catalysts.

Lithium-ion batteries (LIBs) have dominated the secondary batteries market in the past few decades. However, their widespread application is seriously hampered by the limited lithium resource and high cost. Recently, sodium-ion batteries (SIBs) have generated significant attention because of their characteristics of abundant raw sources, low cost, and similar “rocking chair” mechanism with LIBs, which hold great application potential in large-scale energy storage. Cathode materials with excellent electrochemical performance are in urgent demand for next-generation SIBs. Herein, this review provides a comprehensive overview of the recent advances of the most promising SIBs cathode candidates, including layered oxides, polyanionic materials, and Prussian blue analogues. The currently existing issues that need to be addressed for these cathodes are pointed out, such as insufficient energy density, low electron conductivity, air sensitivity, and so on. This review also details the structural characteristics of these three cathode candidates. Moreover, the recent optimization strategies for improving the electrochemical performance are summarized, including element doping, morphology modification, structure architecture, and so on. Finally, the current research status and proposed future developmental directions of these three cathode materials are concluded. This review aims to provide practical guidance for the development of cathode materials for next-generation SIBs.

MXenes have great potential as fast-charging anodes for sodium storage due to their excellent electrical conductivity, high pseudocapacitive charge storage, and large interlayer distance. The intercalation pseudocapacitance provided by the active sites within the laminate MXene nanosheets is generally the major contributor to their sodium-storage capacity. Thus, it is highly preferred to construct porous materials with abundant laminate structures to overcome the ion-diffusion limitation in MXene multilayer films and increase the accessible interlayer sites. Herein, the enhancement of laminate structures in a pre-assembled Ti3C2Tx network is achieved, under the effects of interlayer slipping of MXene nanosheets during capillary densification, and finally obtained a dense monolith with both high density (2.37 g cm−3) and high porosity (87.3 m2 g−1). This MXene anode material delivers a high capacity of 185 mAh g−1 and a superior rate performance of 55 mAh g−1 (5 A g−1). With improvement of both density and gravimetric capacity, this monolith has a high volumetric capacity of up to 200 mAh cm−3 at 1 A g−1 even after 2000 cycles. Herein, new insights are provided into the design of high-capacity MXene anodes for sodium-ion batteries and control of different 2D materials in compact structures.

The clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein (CRISPR/Cas) system has been exploited as an efficient gene editing tool with precise site specificity and high efficiency; the delivery of the CRISPR/Cas system is critical for the efficacy of therapeutics and remains challenging. DNA nanomaterials are widely utilized as promising delivery carriers for gene agents because of their excellent molecular recognition capabilities, sequence programmability, and biocompatibility. Herein, recent advances in DNA nanomaterials for the delivery of CRISPR/Cas systems are summarized. Based on their construction strategy, DNA nanomaterial-based carriers are categorized as branched DNA-based nanostructures or rolling circle amplification (RCA)-based DNA nanostructures. Representative studies on the design of DNA nanomaterials as CRISPR/Cas system delivery carriers are highlighted. The current challenges and opportunities for the development of DNA nanomaterials for the delivery of CRISPR/Cas systems are also discussed. It is envisioned that with the development of DNA nanotechnology, DNA nanomaterials will open up new possibilities for CRISPR/Cas-based therapeutics.

Although the internal electric field (IEF) of bismuth oxyiodide (BiOI) is acknowledged as a potent driving force for efficient charge separation, enhancing the intensity of IEF remains a challenge. Herein, highly crystalline BiOI nanosheets with I-rich surface are employed to intensify IEF and direct the charge migration. In comparison to I-poor BiOI nanosheets, which possess Bi−O layer termination and I-defects, the I-rich BiOI demonstrates 62.5-fold improvement in IEF intensity to its well-developed high crystalline structure, and its IEF direction is reversed by the surface I-rich layers. This intensified IEF of I-rich BiOI induces numerous holes (h+) to migrate to the surface of primary exposed (001) facets and electrons (e−) to the lateral facets efficiently, resulting in efficient charge separation spatially. Additionally, the surface accumulates h+ and superoxide radicals and acts in synergy to enhance the photodegradation of phenol. The photocatalytic activity of the I-rich BiOI is found to be approximately fivefold and threefold higher than that of I-poor BiOI under full spectra and visible light, respectively. Herein, the manipulation of IEF through surface and bulk structure regulation of BiOI for efficient charge separation is discussed, expecting to rationally improve photocatalytic performances.

Bimetallic metal−organic framework (MOF)-derived multidimensional composites have garnered tremendous attention in electromagnetic wave absorption owing to their remarkable attenuation capacity. And the diversified application scenarios require microwaves absorption materials (MAMs) with robust environmentally adaptive, but efficiently integrating multifunctionality within single MAMs is extremely challenging. Herein, a multifunctional CoC@FeNiG-F nanocomposite is fabricated by synergistic strategy of in situ growth, C–F···π interaction and microwave irradiation. The MAMs exhibit a strong reflection loss of −75.18 dB with 3.95 GHz effective absorption bandwidth benefited from magnetic–dielectric attenuation, impedance matching, and multiple-reflection loss. Remarkably, it is first time to obtain the efficient MAMs accompanied with excellent mechanical (80.3 MPa), superamphiphobicity (153° and 151°), anticorrosion (45 d), and flame retardancy (V-0 rating), which illustrate that the combination of CoC@FeNiG 3D-skeleton and long-chain perfluorinated epoxy remarkably improve robust multifunctionality and environmentally adaptive. In particular, the MAMs are assembled into liquid–solid triboelectric nanogenerator, and the output performance (19.7 V, 1.68 μA) and durability (10 000s) are obviously improved benefiting from the trap effect of carbonized MOF. Therefore, this work provides an efficient guideline for designing advanced MAMs with robust environmentally adaptive and sustainable energy harvesting performance in extreme environment application.

The thriving of Internet-of-Things and integrated wireless sensor networks has brought an unprecedented demand for sustainable micro-Watt-scale power supplies. Development of high-performing micro-thermoelectric generator (μ-TEG) that can convert waste thermal energy into electricity and provide sustainable micro-Watt-scale power is therefore extremely timely and important. Herein, a significant advance in the development of earth-abundant, nontoxic thermoelectric materials of aluminum-doped zinc oxide (AZO) is presented. Through nanostructure engineering using a novel in situ O2 plasma treatment, AZO films are demonstrated with ultralow thermal conductivity of 0.16 W m−1 K−1 which is the lowest reported in the literature. This nanostructured film yields a power factor of 294 μW m−1 K−2 at 563 K and has resulted in a state-of-the-art ZT of 0.11 at room temperature and 0.72 at 563 K for AZO thin films. Furthermore, the fabrication and testing of a prototype lateral μ-TEG are reported based on the AZO thin film which achieves a power output of 1.08 nW with an applied temperature difference of 16.9 °C.

As devices become ever smaller and more efficient, the crystallochemically controlled synthesis of high-performance materials that comprise their core has attracted enormous attention. Integration of complex functional materials into the next generation of electronic devices will require exquisite control of anisotropic form, either as nanotubes, nanotapes, or nanowires, yet the easy preparation of abundant quantities of them remains stubbornly challenging. Herein, a template-free, flux-mediated growth of vast quantities of three compositions of phase-pure, high-temperature superconductor nanowires, including for the first time, nanowires of the technologically important quinternary superconductor Bi2Sr2CaCu2O8+x (B2212) is demonstrated. The results of this work may provide an opportunity to investigate the physics and chemistry of highly anisotropic superconductor nanowires and enable their incorporation into nanoelectronics and energy generation systems.

In the past decades, remarkable progress has been achieved in the exploration of electrocatalysts with high activity, long durability, and low cost. Among these, defective graphene (DG)-based catalysts are considered as one of the most potential substitutes for precious metal-based electrocatalysts. DG-based catalysts contain abundant active centers with different configurations resulting from their extraordinary high-structural tunability. Herein, an overview on recent advancements in developing four kinds of DG-based catalysts is presented: 1) heteroatoms-doped graphene; 2) intrinsic DG (vacancy and topological defect); 3) nonmetal atoms or/and metal species-modified intrinsic DG (heterogeneous species and intrinsic defects co-tuned DG); and 4) DG-based van der Waals-type multilayered heterostructures. In particular, the synergistic effects between various defects are discussed, and the origin of catalytic activity is reviewed. Meanwhile, the established defect-derived catalytic mechanism is summarized, which is beneficial for the rational design and fabrication of high-performance electrocatalysts for practical energy-related applications. Finally, challenges and future research directions on defect engineering in noble metal-free materials for electrocatalysis are proposed.

Although various fabrication methods for metal–oxide nanostructures have been well developed for enlarged surface area, numerous efforts to further enhance the effective surface area for their chemical sensor applications are still being studied. Herein, a high-power laser is irradiated on the existing metal–oxide nanostructures to expose the hidden inner surface of the nanostructures for full participation in the surface gas-sensing reactions, resulting in extraordinary gas-sensing performance. In addition, noble metal catalyst decoration at both the inner and outer surfaces of the nanostructures records extremely high gas response and selectivity to volatile organic compounds. The numerical simulation and experimental verification of the effects of high-power laser irradiation for morphological evolution of the metal–oxide nanostructures can provide a new perspective toward the time-efficient development of nanostructure-based electronic devices.

Plant-based flow microreactors with natural channel structures, renewable properties, and environmental friendliness have increasingly gained popularity in heterogeneous catalysis. However, firmly immobilizing the catalysts simultaneously with ease and adaptability, maintaining great effectivity and long-term stability, is still a fundamental challenge. Herein, a highly efficient and ultrastable bamboo-based catalytic microreactor (CMR) containing mesoporous TiO2 (M-TiO2)-encapsulating ultrafine Pd nanoparticles (NPs) is constructed for the continuous-flow hydrogenation of nitroaromatics. The fabrication of the Pd-TiO2 catalysts in required bamboo microchannels (Pd-TiO2/B CMR) mainly involves a two-step region-selective synthetic strategy with ultra-low chemical usage, fast preparation, and low catalyst loading (0.007 wt%). The M-TiO2 films: 1) provide abundant oxygen vacancies and enough open cavities to facilitate the growth of Pd NPs; 2) improve Pd dispersion and reduce particle size; 3) allow diffusion of reactants, and 4) induce strong metal-support interactions for enhanced catalytic activity and stability. The optimized Pd-TiO2/B CMR demonstrates high efficiency (>97%) and excellent stability (1,000 h) for the continuous-flow hydrogenation of nitroaniline, even under intermittent operation (12 h on/12 h off for five cycles) or in a real aqueous matrix (>200 h), making it a promising candidate for Pd-catalyzed hydrogenation.

Traditional-metal-containing scintillators are widely used in X-ray imaging due to their efficient X-ray absorption and output of visible light. However, they suffer from heavy-metal toxicity, environmental stability, harsh preparation, and afterglow. Metal-free organic scintillators show a rising momentum, especially organic-halogen-containing molecules. Halogens are introduced to improve their X-ray absorption, but the resulting increase in spin–orbit coupling leads to significant delayed fluorescence or phosphorescence, affecting the response speed to X-rays. Moreover, there is still insufficient practice in fabricating microstructured organic scintillators for high spatial resolution of imaging. Herein, the preparation of nano organic co-crystals (t-Bpe-IFB co-crystal, abbreviated as BIC, t-Bpe for trans-1,2-bis(4-pyridyl)ethylene, and IFB for 1,3,5-trifluoro-2,4,6-triiodobenzene) and its application in X-ray imaging are explored. In contrast to previous single organic-halogen-containing molecules, BIC generates nanosecond-scale fluorescence through the charge-transfer state of the donor–acceptor. Its high iodine content ensures large X-ray absorption, strong radioluminescence, and a low detection limit of 85 nGyair s−1. The composite film made of nano-sized BICs and polydimethylsiloxane exhibits a high spatial resolution of 16.7 lp mm−1. Herein, the application of organic co-crystals is expanded and ideas are provided for the development of new scintillators.