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The commercialization of lithium-sulfur (Li-S) battery is seriously hindered by the shuttle behavior of lithium (Li) polysulfide, slow conversion kinetics, and Li dendrite growth. Herein, a novel hierarchical p-type iron nitride and n-type vanadium nitride (p-Fe 2 N/n-VN) heterostructure with optimal electronic structure, confined in vesicle-like N-doped nanofibers (p-Fe 2 N/n-VN⊂PNCF), is meticulously constructed to work as "one stone two birds" dual-functional hosts for both the sulfur cathode and Li anode. As demonstrated, the d-band center of high-spin Fe atom captures more electrons from V atom to realize more π* and moderate σ* bond electron filling and orbital occupation; thus, allowing moderate adsorption intensity for polysulfides and more effective d-p orbital hybridization to improve reaction kinetics. Meanwhile, this unique structure can dynamically balance the deposition and transport of Li on the anode; thereby, more effectively inhibiting Li dendrite growth and promoting the formation of a uniform solid electrolyte interface. The as-assembled Li-S full batteries exhibit the conspicuous capacities and ultralong cycling lifespan over 2000 cycles at 5.0 C. Even at a higher S loading (20 mg cm -2 ) and lean electrolyte (2.5 µL mg -1 ), the full cells can still achieve an ultrahigh areal capacity of 16.1 mAh cm -2 after 500 cycles at 0.1 C., (© 2024 Wiley‐VCH GmbH.)

Alloy-type materials are attractive for anodes in sodium-ion batteries (SIBs) owing to their high theoretical capacities and overall performance. However, the accumulation of stress/strain during repeated cycling results in electrode pulverization, leading to rapid capacity decay and eventual disintegration, thus hindering their practical applications. Herein, we report a 3D coral-like Sb-Cu alloy nanoarray with gradient distribution of both elements. The array features a Sb-rich bottom and a Cu-rich top with increasing Sb and decreasing Cu concentrations from top to bottom. The former is the active component that provides the high capacity, whereas the latter serves as an inert additive that acts against volume variation. The gradual transition in composition within the electrode introduces a ladder-type volume expansion effect, facilitating a smooth distribution and effective release of stress, thereby ensuring the wanted mechanical stability and structural integrity. The as-developed nanoarray affords a high reversible capacity (460 mAh g-1 at 0.5 C), stable cycling (89% retention over 120 cycles at 1.0 C), and superior rate capability (354 mAh g-1 at 10 C). The concentration dual-gradient strategy paves a new pathway of designing alloy-type materials for SIBs., (© 2024 Wiley‐VCH GmbH.)

Transition-metal carbides with metallic properties have been extensively used as electrocatalysts due to their excellent conductivity and unique electronic structures. Herein, NbC nanoparticles decorated carbon nanofibers (NbC@CNFs) are proposed as an efficient and robust catalyst for electrochemical synthesis of ammonia from nitrate/nitrite reduction, which achieves a high Faradaic efficiency (FE) of 94.4 % and a large ammonia yield of 30.9 mg h -1  mg -1 cat. . In situ electrochemical tests reveal the nitrite reduction at the catalyst surface follows the *NO pathway and theoretical calculations reveal the formation of NbC@CNFs heterostructure significantly broadens density of states nearby the Fermi energy. Finite element simulations unveil that the current and electric field converge on the NbC nanoparticles along the fiber, suggesting the dispersed carbides are highly active for nitrite reduction., (© 2024 Wiley-VCH GmbH.)

As the atmospheric carbon dioxide (CO 2 ) level keeps hitting the new record, humanity is facing an ever-daunting challenge to efficiently mitigate CO 2 from the atmosphere. Though electrochemical CO 2 reduction presents a promising pathway to convert CO 2 to valuable fuels and chemicals, the general lack of suitable electrocatalysts with high activity and selectivity severely constrains this approach. Herein, a novel class of electrocatalysts is investigated, the quasi-copper-mers, in which the CuN 4 rather than Cu atom itself serve as the basic building block. The respective quasi-copper-monomers, -dimers, and -trimers hosted in a graphene-like substrate are first synthesized and then performed both experimental characterization and density functional theory (DFT) calculations to examine their atomic structures, evaluate their electrocatalytical performance and understand their underlying mechanisms. The experimental results show that the quasi-copper-trimers not only outperform the quasi-copper-dimer and quasi-copper-monomer when catalyzing CO 2 to CO, it also shows a superior selectivity against the competing hydrogen evolution reaction (HER). The DFT calculations not only support the experimental observations, but also reveal the volcano curve and the physical origin for the qausi-copper-trimer superiority. The present work thus presents a new strategy in the design of high-performance electrocatalysts with high activity and selectivity., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Constructing Van der Waals heterojunction is a crucial strategy to achieve excellent photocatalytic activity. However, in most Van der Waals heterojunctions synthesized by ex situ assembly, electron transfer encounters huge hindrances at the interface between the two components due to the large spacing and potential barrier. Herein, a phosphate-bridged Van der Waals heterojunction of cobalt phthalocyanine (CoPc)/tungsten disulfide (WS 2 ) bridged by phosphate (xCoPc-nPO 4 - -WS 2 ) is designed and prepared by the traditional wet chemistry method. By introducing a small phosphate molecule into the interface of CoPc and WS 2 , creates an electron "bridge", resulting in a compact combination and eliminating the space barrier. Therefore, the phosphate (PO 4 - ) bridge can serve as an efficient electron transfer channel in heterojunction and can efficiently transmit photoelectrons from WS 2 to CoPc under excited states. These excited photoelectrons are captured by the catalytic central Co 2+ in CoPc and subsequently convert CO 2 molecules into CO and CH 4 products, achieving 17-fold enhancement on the 3CoPc-0.6PO 4 - -WS 2 sample compared to that of pure WS 2 . Introducing a small molecule "bridge" to create an electron transfer channel provides a new perspective in designing efficient photocatalysts for photocatalytic CO 2 reduction into valuable products., (© 2023 Wiley-VCH GmbH.)

Na 3 V 2 (PO 4 ) 3 (NVP) is a widely studied cathode material for sodium-ion batteries because of its high ionic conductivity and attractive charge/discharge plateau (3.4 V vs. Na/Na + ). However, its poor electronic conductivity and severe volume expansion during sodium storage need to be addressed before its intensive application could be realized. Herein, boron-doped NVP was synthesized through a facile electrospinning method. By adding boric acid into the reaction mixture during electrospinning followed by carbonization, boron could be directly inserted into the carbon matrix, giving rise to B-doped carbon nanofiber wrapped NVP. By tuning the doping amount, the boron-containing configurations could be facilely manipulated, playing different roles in promoting the sodium storage properties of the composite. Based on the calculation results, BC 2 O enhanced sodium diffusion by lowering the energy barrier, while BCO 2 improved the structural stability. Due to these specific functionalities of the configurations, the as-prepared composite with a balanced amount of BC 2 O and BCO 2 demonstrated superior sodium storage capacity of 113 mAh g -1 at 1 C, outstanding long cycling performance of 103 mAh g -1 at 10 C, and retained 91 mAh g -1 after 1500 cycles. This gave rise to a capacity loss of only 0.08‰ per cycle, much better than the undoped counterpart., (© 2022 Wiley-VCH GmbH.)

Atomically dispersed iron immobilized on nitrogen-doped carbon catalyst has attracted enormous attention for CO 2 electroreduction, but still suffers from low current density and poor selectivity. Herein, atomically dispersed FeN 5 active sites supported on defective N-doped carbon successfully formed by a multistep thermal treatment strategy with the aid of dicyandiamide are reported. This dual-functional strategy can not only construct intrinsic carbon defects by selectively etching pyridinic-N and pyrrolic-N, but also introduces an additional N from the neighboring carbon layer coordinating to the commonly observed FeN 4 , thus creating an FeN 5 active site supported on defective porous carbon nanofibers (FeN 5 /DPCF) with a local 3D configuration. The optimized FeN 5 /DPCF achieves a high CO Faradaic efficiency (>90%) over a wide potential range of -0.4 to -0.6 V versus RHE with a maximal FE CO of 93.1%, a high CO partial current density of 9.4 mA cm -2 at the low overpotential of 490 mV, and a remarkable turnover frequency of 2965 h -1 . Density functional theory calculations reveal that the synergistic effect between the FeN 5 sites and carbon defects can enhance electronic localization, thus reducing the energy barrier for the CO 2 reduction reaction and suppressing the hydrogen evolution reaction, giving rise to the superior activity and selectivity., (© 2022 Wiley-VCH GmbH.)

Aqueous Zn metal batteries (AZMBs) have been considered as a promising alternative to the existing Li-ion batteries. Nevertheless, the large-scale application of the AZMBs is restricted by the dendrite formation and side reactions within the Zn metal anodes (ZMAs) during cycling. Herein, an atomically dispersed Cu in leaf-like Zn-coordinated zeolitic imidazolate framework (ZIF-L) nanoflakes on Ti mesh (CuZIF-L@TM) as ZMA host is developed. The 3D conductive network formed by the interconnected ZIF-L nanoflakes can reduce the local current density and homogenize the electric field distribution. Moreover, experimental data and theoretical calculations reveal the Cu single atoms within the ZIF-L can serve as the zincophilic sites to facilitate the Zn deposition. As expected, the CuZIF-L@TM host enables a homogeneous Zn deposition on the surface without dendrites. The resultant CuZIF-L@TM/Zn electrode shows stable Zn plating/stripping over 1100 h at 1 mA cm -2 with a low voltage hysteresis of about 50 mV. As a proof of concept, a full cell based on the designed CuZIF-L@TM/Zn anode shows a stable cycling performance over 1000 cycles., (© 2022 Wiley-VCH GmbH.)

Tin-based compounds have received much attention as anode materials for lithium/sodium ion batteries owing to their high theoretical capacity. However, the huge volume change usually leads to the pulverization of electrode, giving rise to a poor cycle performance, which have severely hampered their practical application. Herein, highly durable yolk-shell SnSe 2 nanospheres (SnSe 2 @SeC) are prepared by a multistep templating method, with an in situ gas-phase selenization of the SnO 2 @C hollow nanospheres. During this process, Se can be doped into the carbon shell with a tunable amount and form SeC bonds. Density functional theory calculation results reveal that the SeC bonding can enhance the charge transfer properties as well as the binding interaction between the SnSe 2 core and the carbon shell, favoring an improved rate performance and a superior cyclability. As expected, the sample delivers reversible capacities of 441 and 406 mAh g -1 after 2000 cycles at 2 and 5 A g -1 , respectively, as the anode material for a sodium-ion battery. Such performances are significantly better than the control sample without the SeC bonding and also other metal selenide-based anodes, evidently showing the advantage of Se doping in the carbon shell., (© 2020 Wiley-VCH GmbH.)

The development of new electrode materials for lithium-ion batteries (LIBs) has always been a focal area of materials science, as the current technology may not be able to meet the high energy demands for electronic devices with better performance. Among all the metal oxides, tin dioxide (SnO₂) is regarded as a promising candidate to serve as the anode material for LIBs due to its high theoretical capacity. Here, a thorough survey is provided of the synthesis of SnO₂-based nanomaterials with various structures and chemical compositions, and their application as negative electrodes for LIBs. It covers SnO₂ with different morphologies ranging from 1D nanorods/nanowires/nanotubes, to 2D nanosheets, to 3D hollow nanostructures. Nanocomposites consisting of SnO₂ and different carbonaceous supports, e.g., amorphous carbon, carbon nanotubes, graphene, are also investigated. The use of Sn-based nanomaterials as the anode material for LIBs will be briefly discussed as well. The aim of this review is to provide an in-depth and rational understanding such that the electrochemical properties of SnO₂-based anodes can be effectively enhanced by making proper nanostructures with optimized chemical composition. By focusing on SnO₂, the hope is that such concepts and strategies can be extended to other potential metal oxides, such as titanium dioxide or iron oxides, thus shedding some light on the future development of high-performance metal-oxide based negative electrodes for LIBs., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)