State Key Laboratory of Metastable Materials Science and Technology

Lithium–sulfur batteries have attracted increasing attention as one of the most promising candidates for next-generation energy storage systems. However, the poor cycling performance and the low utilization of sulfur greatly hinder its practical applications. Here we report the improved performance of lithium–sulfur batteries by coating Ti3C2Tx MXene nanosheets (where T stands for the surface termination, such as -O, -OH, and/or -F) on commercial “Celgard” membrane. In favor of the ultrathin two-dimensional structure, the Ti3C2Tx MXene can form a uniform coating layer with a minimum mass loading of 0.1 mg cm–2 and a thickness of only 522 nm. Owing to the improved electric conductivity and the effective trapping of polysulfides, the lithium–sulfur batteries with MXene-functionalized separators exhibit superior performance including high specific capacities and cycling stability.

/MXene@Ag nanoparticle composite film fabricated by electrospinning and heat treatment as well as self-reduction reaction process. The obtained composite films showed high self-reduction ability because of the incorporation of MXene flakes. The intercalated MXene flakes in the composite nanofibers were evenly distributed, which not only solved the aggregation problem from MXene dispersion but also could self-reduce Ag nanoparticles in situ in composite materials. In addition, the composite nanofiber films exhibited good fiber structure, thermal stability, and magnetic properties. Moreover, the composite nanofiber films demonstrated excellent catalytic ability and cycle stability to 4-nitrophenol and 2-nitroaniline.

Single atom Pt significantly improves the sensing performances of ultrathin SnO₂ films for detection of triethylamine.

A universal and facile approach using a graphene oxide (GO) modified separator is used to suppress dendrite formation in Zn and Li metal anodes, <italic>via</italic> the preferential growth of non-protruding crystal planes.

A novel 2D material is prepared by<italic>in situ</italic>phase transformation of layered MXene with the induction of Fe(<sc>iii</sc>) ion. The urchin-like rutile TiO₂–C nanocomposite with a high amount of (110) facets exhibits a high Cr(<sc>vi</sc>) adsorption ability of ~225 mg g⁻¹, which is the highest value based on a simple adsorption mechanism reported so far

First-principles calculations predicted a MgH₆ phase with a high superconducting critical temperature of ∼260 K under high pressure.

Based on the detailed analysis of chemical bonds, we present a Vickers hardness expression for the covalency-dominant crystals such as transition-metal carbides and nitrides. Hardness is dependent not only on bond length, bond density, and ionicity of bond [F. M. Gao et al., Phys. Rev. Lett. 91, 015502 (2003)] but also on the metallicity of bond and orbital form in the crystal structure of a compound, and all of these parameters can be determined by first-principles calculations. The calculated hardness using our expression has a good agreement with the experimental values for known monocarbides, mononitrides of transition metals, and cubic Zr3N4 with Th3P4 structure. In addition, we have predicted the Vickers hardness of the recently predicted tetragonal BC3 and tetragonal B2CN, and the recently synthesized pyrite PtN2 and marcasite OsN2. Our method offers one useful technique to search for superhard materials in transition-metal carbides and nitrides.

Abstract Rechargeable aqueous zinc‐ion batteries (ZIBs) have attracted extensive interest owing to their low cost and high safety. Herein, oxygen‐defective potassium vanadate/amorphous carbon nanoribbons (C‐KVO|O d ) are successfully synthesized through a one‐step solid‐state sintering process as a high‐performance cathode material for ZIBs. This unique 3D interconnected network structure can not only act as a continuous conductive path but also decrease aggregation and provide more adsorption sites for zinc ions. The as‐prepared C‐KVO|O d exhibits a high capacity of 385 mAh g −1 at 0.2 A g −1 , superior rate performance (166 mAh g −1 even at 20 A g −1 ), and an outstanding cycling stability with a 95% capacity retention over 1000 cycles. Density functional theory calculations elucidate that the oxygen defects in the C‐KVO|O d remarkably reduce the Zn 2+ ion's adsorption Gibbs free energy and Zn 2+ ‐diffusion barriers. Meanwhile, the amorphous carbon networks enable the rapid electron transfer and provide additional active sites for Zn 2+ storage. This work can facilitate the development of high‐performance ZIBs for large‐scale energy storage.

A key challenge in synthesizing anisotropic nanocomposite magnets is to form crystallographic texture for R2Fe14B crystals in R-lean alloys (R=rare earth, R&amp;lt;10 at. %). Here, we demonstrate a (00l) texture development for Nd2Fe14B nanocrystals in a Nd-lean amorphous Nd9Fe85B6 under a hot deformation at a large uniaxial stress of ∼310 MPa. The unusual texture formation is attributed to a preferential nucleation of Nd2Fe14B crystals in amorphous matrix at the large stress. The present study provides an opportunity to yield anisotropic nanocomposite magnets from Nd-lean alloys and thus is of wide interest.

A low-cost and eco-friendly solution coating of nanoscale Al₂O₃ addresses the high-voltage fast degradation of LiCoO₂.

value could be assigned to a good packing induced strong luminescence of an excimer. This strategy provides an efficient way to fabricate higher dissymmetry factor CPL organic nanomaterials by only changing the supramolecular architectures while using the same chiral small molecules.

Abstract Fe–N–C catalyst for oxygen reduction reaction (ORR) has been considered as the most promising nonprecious metal catalyst due to its comparable catalytic performance to Pt in proton exchange membrane fuel cells (PEMFCs). The active centers of Fe–pyrrolic N 4 have been proven to be extremely active for ORR. However, forming a stable Fe–pyrrolic N 4 structure is a huge challenge. Here, a Cyan‐Fe–N–C catalyst with Fe–pyrrolic N 4 as the intrinsic active center is constructed with the help of axial Fe 4 C atomic clusters, which shows a half‐wave potential of up to 0.836 V (vs. RHE) in the acid environment. More remarkably, it delivers a high power density of 870 and 478 mW cm −2 at 1.0 bar in H 2 –O 2 and H 2 –Air fuel cells, respectively. According to theoretical calculation and in situ spectroscopy, the axial Fe 4 C can provide strong electronic perturbation to Fe–N 4 active centers, leading to the d‐orbital electron delocalization of Fe and forming the Fe–pyrrolic N 4 bond with high charge distribution, which stabilizes the Fe–pyrrolic N 4 structure and optimizes the OH* adsorption during the catalytic process. This work proposes a new strategy to adjust the electronic structure of single‐atom catalysts based on the strong interaction between single atoms and atomic clusters.

3D interconnected porous carbon nanosheets/carbon nanotubes as the host for lithium–sulfur batteries are synthesized <italic>via</italic> a simple one-pot pyrolysis strategy.

Abstract As wearable sensors advance rapidly, demands for multifunctional conductive soft materials are ever higher, including high stretchability, resilience, adhesiveness and stability, simultaneously in one material, for stable long‐term use. Nanocomposite hydrogels incorporating conductive two‐dimensional (2D) nanofillers, such as MXene‐composited gels, emerge as promising candidates. Yet, fulfilling all above requirements, particularly large stretchability with low hysteresis, remains a challenge, owing to the easy oxidation and weak interactions of MXene nanosheets with polymer chains. Herein, an interfacial engineering strategy is proposed, where tannic acid (TA) with high‐density hydroxyl groups is introduced to encapsulate MXene into a stable TA@MXene nano‐motif and meanwhile increase the hydrogen‐bonding interactions between TA@MXene and polymer network. By incorporating TA@MXene into poly(hydroxyethyl acrylate) (PHEA) network in a glycerol/water binary solvent, the obtained organohydrogel exhibits integrated properties of high stretchability (&gt;500%) with low hysteresis (&lt;3%), superior fatigue resistance (consistent hysteresis over 500 cycles at 300% strain), good adhesiveness, along with long‐term stability (&gt;7 days) and antifreezing abilities (−40 °C). Such organohydrogels demonstrate superior strain‐sensitivity and thermosensitive capacities, enabling accurate and reliable detection of human movements, electrocardiogram signals, and body temperature. This general approach of stabilizing nanomaterials while effectively enhancing nanomaterial‐polymer bonding is applicable for synthesizing diverse high‐performance nanocomposited gels.

This review summarizes the impact of the electro-chemo-mechanics of lithium on dendrites and interfaces in solid state lithium metal batteries.

In this work, we successfully prepared the mussel-inspired polydopamine microspheres (PDA-Ms) with controllable sizes, through a facile self-oxidative polymerization method. The prepared PDA-M biomaterial with environmentally benign properties exhibits efficient lead(II) sequestration against high salts of competitive Ca(II), Mg(II), or Na(I) ions. It reveals 30 times greater than the commercial ion-exchanger 001x7 by selectivity evaluation. Kinetic results show that an exceedingly rapid lead(II) uptake can be achieved below 1 min. More attractively, the prepared PDA-Ms further exhibit the distinguished application ability with superior treated capacity of ∼42000 kg contaminated water/kg sorbent, and the effluents can be reduced from 1000 μg/L to below 10 μg/L, reaching the drinking water standard (WHO), which is equal to 200 times greater than commercial ion exchanger resin (∼210 kg) and granular activated carbon (∼120 kg). In addition, the exhaust PDA-M material can be well regenerated and repeated use using binary 1% HCl + 5% Ca(NO3)2 solution. X-ray photoelectron spectroscopy (XPS), zeta potential, and FT-IR analysis prove that such satisfactory performances can be ascribed to the following aspects (1) the well-dispersed nanoscale morphology and highly charged property will achieve the rapid adsorption and sufficient sorbent utilization. That is, the negatively-charged PDA sphere can exert the famous Donnan membrane effects for target lead(II) enrichment and diffusion enhancement; (2) the strong amine and carbonyl/hydroxyl group within the matrix can offer sorption selectivity for powerful lead(II) capture. Effective performances as well as environmentally friendly features suggest PDA-M material is a promising lead(II)-removing candidate for water remediation.

Photodynamic therapy (PDT) is a promising treatment against multiantibiotic-resistant bacteria with the advantage of a low tendency towards antibiotic resistance. Due to their high PDT efficiencies and superior chemical stabilities, fullerenes have been proposed as effective photosensitizers for the photodynamic inactivation of bacteria. However, the biomedical applications of fullerenes are hindered by their limited aqueous solubility and apparent tendency to undergo aggregation. Herein, we report a hybrid supramolecular hydrogel prepared by the peptide-modulated self-assembly of fullerenes for targeted and sustained photodynamic antibacterial therapy. Aggregation of the fullerene in the hydrogel is largely inhibited through the non-covalent interactions between the peptide and the fullerene. Consequently, the PDT efficiency of the peptide-fullerene hydrogel is highly improved as compared to the untreated fullerene. The incorporation of fullerene profoundly improves the mechanical properties of the hydrogel, making the peptide-fullerene hydrogel a better injectable formulation for biomedical applications. In vitro and in vivo antibacterial results indicate that the peptide-fullerene hydrogels can effectively inhibit multiantibiotic-resistant Staphylococcus aureus and promote wound healing. This study offers a promising paradigm to adapt self-assembling small peptides with integration of multiple functions for biomedical applications.

occupancy in the lithium layer enhances the electrochemical performance of layered NMC materials and that this occurs through a "pillaring" effect. The results provide new insights into "cation mixing" as a new concept for material design utilization of layered cathodes for lithium-ion batteries, thereby promoting their further application in lithium-ion batteries with new functions and properties.

The useful functionalization and self-assembly of two-dimensional layered materials like hydrotalcite (LDH) are critical for the wide application of nanomaterials. In this work, some self-assembled Langmuir films of ion-exchanged LDH and dyes with different molecular structures were prepared by the Langmuir–Blodgett (LB) technique. The aggregation states of used dye molecules on the surface of the obtained membrane and the structures/properties of the membrane were studied. The hydroxyethyl sulfonate-inserted LDH (LDH-Ise) nanosheets were able to induce the dye formation of highly ordered H- and/or J-aggregate structures. Surface-enhanced Raman scattering (SERS) spectroscopy results demonstrated the uniformity and repeatability of the film. Interestingly, the good acid–base gas response characteristics of present LDH-Ise/dye LB films were investigated by UV–vis and Fourier transform infrared (FT-IR). The present research work provides new clues for the development of gas sensors and chemical switches as well as the preparation of effective functional self-assembled films.

The power factor was significantly enhanced benefiting from texture modulation, resulting in a<italic>ZT</italic>of ∼1.0 in p-type polycrystalline SnSe.