Yolk-Shell Sb@Void@Graphdiyne Nanoboxes for High-Rate and Long Cycle Life Sodium-Ion Batteries

Antimony (Sb) has been pursued as a promising anode material for sodium-ion batteries (SIBs). However, it suffers from severe volume expansion during the sodiation-desodiation process. Encapsulating Sb into a carbon matrix can effectively buffer the volume change of Sb. However, the sluggish Na⁺ diffusion kinetics in traditional carbon shells is still a bottleneck for achieving high-rate performance in Sb/C composite materials. Here we design and synthesize a yolk-shell Sb@Void@graphdiyne (GDY) nanobox (Sb@Void@GDY NB) anode for high-rate and long cycle life SIBs. The intrinsic in-plane cavities in GDY shells offer three-dimensional Na⁺ transporting channels, enabling fast Na⁺ diffusion through the GDY shells. Electrochemical kinetics analyses show that the Sb@Void@GDY NBs exhibit faster Na⁺ transport kinetics than traditional Sb@C NBs. In situ transmission electron microscopy analysis reveals that the hollow structure and the void space between Sb and GDY successfully accommodate the volume change of Sb during cycling, and the plastic GDY shell maintains the structural integrity of NBs. Benefiting from the above structural merits, the Sb@Void@GDY NBs exhibit excellent rate capability and extraordinary cycling stability.

Sodium-Ion Battery with a Wide Operation-Temperature Range from -70 to 100 °C

Sodium-ion batteries (SIBs), as one of the potential candidates for grid-scale energy storage systems, are required to tackle extreme weather conditions. However, the all-weather SIBs with a wide operation-temperature range are rarely reported. Herein, we propose a wide-temperature range SIB, which involves a carbon-coated Na₄ Fe₃ (PO₄ )₂ P₂ O₇ (NFPP@C) cathode, a bismuth (Bi) anode, and a diglyme-based electrolyte. We demonstrate that solvated Na⁺ can be directly stored by the Bi anode via an alloying reaction without the de-solvent process. Furthermore, the NFPP@C cathode exhibits a high Na⁺ diffusion coefficient at low temperature. As a result, the Bi//NFPP@C battery exhibits perfect low-temperature behavior. Even at -70 °C, this battery still delivers 70.19 % of the room-temperature capacity. Furthermore, benefitting from the high boiling point of the electrolyte, this battery also works well at a high temperature of up to 100 °C. These results are encouraging for the further exploration of wide-temperature range SIBs.

In Situ Growth of Three-Dimensional MXene/Metal-Organic Framework Composites for High-Performance Supercapacitors

In this study, we propose a versatile method for synthesizing uniform three-dimensional (3D) metal carbides, nitrides, and carbonitrides (MXenes)/metal-organic frameworks (MOFs) composites (Ti₃ C₂ T_X /Cu-BTC, Ti₃ C₂ T_X /Fe,Co-PBA, Ti₃ C₂ T_X /ZIF-8, and Ti₃ C₂ T_X /ZIF-67) that combine the advantages of MOFs and MXenes to enhance stability and improve conductivity. Subsequently, 3D hollow Ti₃ C₂ T_X /ZIF-67/CoV₂ O₆ composites with excellent electron- and ion-transport properties derived from Ti₃ C₂ T_X /ZIF-67 were synthesized. The specific capacitance of the Ti₃ C₂ T_X /ZIF-67/CoV₂ O₆ electrode was 285.5 F g^-1 , which is much higher than that of the ZIF-67 and Ti₃ C₂ T_X /ZIF-67 electrode. This study opens a new avenue for the design and synthesis of MXene/MOF composites and complex hollow structures with tailorable structures and compositions for various applications.

Design of Multi-Shelled Hollow Cr2 O3 Spheres for Metabolic Fingerprinting

Schizophrenia (SZ) detection enables effective treatment to improve the clinical outcome, but objective and reliable SZ diagnostics are still limited. An ideal diagnosis of SZ suited for robust clinical screening must address detection throughput, low invasiveness, and diagnosis accuracy. Herein, we built a multi-shelled hollow Cr₂ O₃ spheres (MHCSs) assisted laser desorption/ionization mass spectrometry (LDI MS) platform for the direct metabolic profiling of biofluids towards SZ diagnostics. The MHCSs displayed strong light absorption for enhanced ionization and microscale surface roughness with stability for the effective LDI of metabolites. We profiled urine and serum metabolites (≈1 μL) with the enhanced LDI efficacy in seconds. We discriminated SZ patients (SZs) from healthy controls (HCs) with the highest area under the curve (AUC) value of 1.000 for the blind test. We identified four compounds with optimal diagnostic power as a simplified metabolite panel for SZ and demonstrated the metabolite quantification for clinic use. Our approach accelerates the growth of new platforms toward a precision diagnosis in the near future.

Rationally Designed Three-Layered Cu2 S@Carbon@MoS2 Hierarchical Nanoboxes for Efficient Sodium Storage

Hybrid materials, integrating the merits of individual components, are ideal structures for efficient sodium storage. However, the construction of hybrid structures with decent physical/electrochemical properties is still challenging. Now, the elaborate design and synthesis of hierarchical nanoboxes composed of three-layered Cu₂ S@carbon@MoS₂ as anode materials for sodium-ion batteries is reported. Through a facile multistep template-engaged strategy, ultrathin MoS₂ nanosheets are grown on nitrogen-doped carbon-coated Cu₂ S nanoboxes to realize the Cu₂ S@carbon@MoS₂ configuration. The design shortens the diffusion path of electrons/Na⁺ ions, accommodates the volume change of electrodes during cycling, enhances the electric conductivity of the hybrids, and offers abundant active sites for sodium uptake. By virtue of these advantages, these three-layered Cu₂ S@carbon@MoS₂ hierarchical nanoboxes show excellent electrochemical properties in terms of decent rate capability and stable cycle life.

A robust host-guest interaction controlled probe immobilization strategy for the ultrasensitive detection of HBV DNA using hollow HP5-Au/CoS nanobox as biosensing platform

The combination of supramolecular chemistry and nanotechnology has potentially applied in the construction of biosensors, and thus improves the analytical performance and robustness of electron devices. Herein, a new sandwich-type DNA sensor was constructed for ultrasensitive determination of hepatitis B virus (HBV) DNA, a recognized marker for chronic hepatitis B. The water-soluble pillar[5]arene stabilized Pd NPs combined with reduced graphene oxide nanosheet (WP5-Pd/RGO) was synthesized and employed as supporting material for the modification of electrode surface. The probe DNA was immobilized onto the electrode surface through a new strategy based on the host-guest interaction between WP5 and methylene blue labeled DNA (MB-DNA). Moreover, MOF-derived cobalt sulfide nanobox was prepared to anchor the hydroxylatopillar[5]arene stabilized Au NPs (HP5-Au/CoS), which had superior electrocatalytic performance towards H₂O₂ reduction to achieve signal amplification. Under the optimized conditions, the proposed sensor displayed a linear relationship between amperometric currents and the logarithm of tDNA solution from 1 × 10^-15 mol/L to 1 × 10^-9 mol/L, and a low detection limit of 0.32 fmol/L. What's more, the DNA sensor had remarkable behaviors of stability, reproducibility, specificity, and accuracy, which provided a potential and promising prospect for clinical diagnosis and analysis.

Topotactic Transformation Synthesis of 2D Ultrathin GeS2 Nanosheets toward High-Rate and High-Energy-Density Sodium-Ion Half/Full Batteries

Currently, development of metal sulfide anodes for sodium-ion batteries (SIBs) with high capacity, fast charging/discharging, and good cycling performance continues to present a great challenge. Hence, a topochemical conversion strategy is reported to fabricate 2D ultrathin GeS₂ nanosheets (thickness: ∼1.2 nm) as the potential anodes for sodium storage. The 2D ultrathin nanostructure can mitigate the electrode-electrolyte contact issue faced by bulk material and provide shorter transport/diffusion pathways for Na ions and electrons, resulting in excellent rate performance. Impressively, ultrathin GeS₂ nanosheets can bring a large capacity of 515 mAh g^-1 even after 2000 cycles under 10 A g^-1. Additionally, as revealed by calculations and in situ/ex situ technique analysis, a favorable mechanism of Na⁺ intercalation/deintercalation into/from the GeS₂ interlayer region (GeS₂ ↔ Na_xGeS₂) is demonstrated. Furthermore, when coupled with the advanced cathode of Na₃V₂(PO₄)₂O₂F, the sodium-ion full cell shows a stable high energy density (213 Wh kg^-1), which makes our ultrathin GeS₂ nanosheets a promising candidate for SIBs.

Constructing MoS2/CoMo2S4/Co3S4 nanostructures supported by graphene layers as the anode for lithium-ion batteries

With the increasing energy demand, it is very urgent to develop new anode materials for lithium ion batteries (LIBs). Designing nanostructures and constructing multicomponent metal sulfides are vital for enhancing the electrochemical performance. This study reports a new synthetic method to construct MoS2/CoMo2S4/Co3S4 nanostructures supported by graphene. A key step in the process, high temperature annealing, promotes the interdiffusion of metal sulfides to form multicomponent metal sulfides and establishes a strong C-S bond between the MoS2/CoMo2S4/Co3S4 nanostructure and graphene. The unique nanostructure and synergistic effects between the conductive graphene and the MoS2/CoMo2S4/Co3S4 nanostructure endows the material with good lithium storage. As a result, it exhibits a good rate performance (360 mA h g-1 at 10 A g-1) and a high specific capacity (770 mA h g-1 at 0.2 A g-1). This study provides a unique method to construct promising anode materials for the application of LIBs.

Construction of Hierarchical Nanotubes Assembled from Ultrathin V3 S4 @C Nanosheets towards Alkali-Ion Batteries with Ion-Dependent Electrochemical Mechanisms

Ultrathin core-shell V₃ S₄ @C nanosheets assembled into hierarchical nanotubes (V₃ S₄ @C NS-HNTs) are synthesized by a self-template strategy and evaluated as general anodes for alkali-ion batteries. Structural/physicochemical characterizations and DFT calculations bring insights into the intrinsic relationship between crystal structures and electrochemical mechanisms of the V₃ S₄ @C NS-HNTs electrode. The V₃ S₄ @C NS-HNTs are endowed with strong structural rigidness owing to the layered VS₂ subunits and interlayer occupied V atoms, and efficient alkali-ion adsorption/diffusion thanks to the electroactive V₃ S₄ -C interfaces. The resulting V₃ S₄ @C NS-HNTs anode exhibit distinct alkali-ion-dependent charge storage mechanisms and exceptional long-durability cyclic performance in storage of K⁺ , benefiting from synergistic contributions of pseudocapacitive and reversible intercalation/de-intercalation behaviors superior to those of the conversion-reaction-based Li⁺ -/Na⁺ -storage counterparts.

Engineering the coupling interface of rhombic dodecahedral NiCoP/C@FeOOH nanocages toward enhanced water oxidation

Hydrogen, regarded as one of the most promising green and sustainable energy resources, could be generated by splitting water with electrochemical methods. The challenge for efficient hydrogen generation is the sluggish kinetics at the anodes for the oxygen evolution reaction (OER). Here, a novel catalyst with remarkably enhanced OER activity was prepared by coupling FeOOH and NiCoP/C. The enhanced OER activity of the hybrid catalyst should be ascribed to the synergistic effect of the individual components. First, NiCoP/C derived from ZIF-67 with a hollow rhombic dodecahedral architecture not only allows exposure of numerous active sites but also provides high conductivity. Second, the re-localization of electrons at the coupling interface optimizes the adsorption/desorption nature of intermediate oxygenated species and imparts a high OER activity. The hybrid NiCoP/C@FeOOH catalyst exhibits very high OER activity with a low overpotential of 271 mV for producing a current density of 10 mA cm^-2 in 1 M KOH aqueous solution, markedly surpassing the individual counterparts of pure NiCoP/C nanocages and bare FeOOH. This work represents a universal strategy for boosting the OER kinetics of catalysts and pushing boundaries for high-efficiency water oxidation.

Recent advances in metal sulfides: from controlled fabrication to electrocatalytic, photocatalytic and photoelectrochemical water splitting and beyond

This review describes an in-depth overview and knowledge on the variety of synthetic strategies for forming metal sulfides and their potential use to achieve effective hydrogen generation and beyond.

Self-ZIF template-directed synthesis of a CoS nanoflake array as a Janus electrocatalyst for overall water splitting

Self-ZIF template-directed synthesis of a CoS nanoflake array as a Janus electrocatalyst for overall water splitting.