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High‐entropy oxides (HEOs) have been showing great promise in a wide range of applications. There remains a lack of clarity regarding the influence of nanostructure and composition on their Li storage performance. Herein, a dealloying technique to synthesize hierarchical nanoporous HEOs with tunable compositions is employed. Building upon the extensively studied quinary AlFeNiCrMnOx, an additional element (Co, V, Ti, or Cu) is introduced to create senary HEOs, allowing for investigation of the impact of the added component on Li storage performance. With higher specific surface areas and oxygen vacancy concentrations, all their HEOs exhibit high Li storage performances. Remarkably, the senary HEO with the addition of V (AlNiFeCrMnVOx) achieves an impressive capacity of 730.2 mAh g−1 at 2.0 A g−1, which surpasses all reported performance of HEOs. This result demonstrates the synergistic interaction of the six elements in one HEO nanostructure. Additionally, the battery cycling‐induced reconstruction and cation diffusion in the HEOs is uncovered, which results in an initial capacity decrease followed by a subsequent continuous capacity increase and enhanced Li ion diffusion. The results highlight the crucial roles played by both nanoporous structure design and composition optimization in enhancing Li storage of HEOs. [ABSTRACT FROM AUTHOR]

Highlights Due to the exceptional flame retardancy, environmental protection, cost‐effectiveness, and ease of processing, halogen‐free flame‐retardant polyethylene (PE) composites are attracting wide attention. However, the addition of halogen‐free flame retardants usually leads to significantly decreased mechanical properties of PE composites, which greatly limits its application. Herein, we report a halogen‐free flame‐retardant PE/ethylene‐vinyl acetate copolymer composite (PE/EVA) with excellent flame retardancy and mechanical properties by combining compatibilizer, crosslinking agent, and carbon fiber. The presence of compatibilizer not only improves the compatibility of halogen‐free flame retardants and matrix, but also interacts with the crosslinking agent to form a cladding structure on the surface of carbon fiber. The enhanced interaction between carbon fiber surface and matrix then results in significantly enhanced flame retardancy and mechanical properties of the composite. Specifically, adding 4 phr compatibilizer, 0.5 phr crosslinking agent, and 10 phr carbon fiber will lead to the halogen‐free flame‐retardant PE/EVA composite with a UL‐94 V‐1 level, limiting oxygen index of 27.1, and an increased tensile strength by 84.02% reaching 19.12 MPa. Moreover, further carbon fiber surface modification can further enhance the flame retardancy of the composite probably due to a synergistic flame‐retardant effect caused by the surface modified nitrogen and silicon elements. As a result, the composite achieves UL‐94 V‐0 level and the limiting oxygen index of 27.7 with well‐retained high tensile strength of 15.19 MPa. This work provides a practical strategy for enhancing the flame retardancy and mechanical property of PE‐based composite simultaneously. Compatibilizer interacts with crosslinking agent to form a cladding structure on the surface of carbon fiber. Crosslinking agent promotes the formation of chemical bonds between modified carbon fiber, compatibilizer, and matrix. Carbon fiber surface modification can enhance the flame retardancy of the composite due to the synergistic flame‐retardant effect. [ABSTRACT FROM AUTHOR]

With a high theoretical capacity, the MnS anode, however, exhibits a rather complex sodium diffusion kinetics and poor mechanical stability that hinder its application in sodium-ion batteries (SIBs). In this work, a simple, economical, and scalable strategy is developed to inherently coat nanoporous MnS with a 3D N, S co-doped thin carbon layer by using commercially available MnCO 3 as precursors. Specifically, the strategy involves a two-step annealing process, which converts the MnCO 3 microparticles into nanoporous Mn 2 O 3 and MnS step by step. The 3D N, S codoped carbon layer is in situ formed during the second annealing process by first coating the nanoporous Mn 2 O 3 with a polyaniline layer. Due to the inherent 3D carbon protection and the strong electronic interaction between N, S dopants and MnS, the N, S codoped carbon protected MnS obtained at 900 °C (NS-C@MnS-900) anode displays a high specific capacity of 845 mAh g -1 at 0.1 A g -1 , which is higher than all reported MnS-based SIB anodes. It also shows an outstanding cyclability and rate performance, maintaining a stable capacity of ≈493 mAh g -1 after 1300 cycles at 10 A g -1 , which is also the best according to knowledge. These exceptional electrochemical performances and the scalable/simple/low-cost synthesis make the NS-C@MnS-900 attractive for industry application., (© 2024 Wiley‐VCH GmbH.)

Developing electrocatalysts with excellent activity and stability for water splitting in acidic media remains a formidable challenge due to the sluggish kinetics and severe dissolution. As a solution, a multi-component doped RuO 2 prepared through a process of dealloying-annealing is presented. The resulting multi-doped RuO 2 possesses a nanoporous structure, ensuring a high utilization efficiency of Ru. Furthermore, the dopants can regulate the electronic structure, causing electron aggregation around unsaturated Ru sites, which mitigates Ru dissolution and significantly enhances the catalytic stability/activity. The representative catalyst (FeCoNiCrTi-RuO 2 ) shows an overpotential of 167 mV at 10 mA cm -2 for oxygen evolution reaction (OER) in 0.5 m H 2 SO 4 solution with a Tafel slope of 53.1 mV dec -1 , which is among the highest performance reported. Moreover, it remains stable for over 200 h at a current density of 10 mA cm -2 . This work presents a promising approach for improving RuO 2 -based electrocatalysts, offering a crucial advancement for electrochemical water splitting., (© 2024 Wiley‐VCH GmbH.)

Developing single-atomic catalysts with superior selectivity and outstanding stability for CO 2 electroreduction is desperately required but still challenging. Herein, confinement strategy and three-dimensional (3D) nanoporous structure design strategy are combined to construct unsaturated single Ni sites (Ni-N 3 ) stabilized by pyridinic N-rich interconnected carbon nanosheets. The confinement agent chitosan and its strong interaction with g-C 3 N 4 nanosheet are effective for dispersing Ni and restraining their agglomeration during pyrolysis, resulting in ultrastable Ni single-atom catalyst. Due to the confinement effect and structure advantage, such designed catalyst exhibits a nearly 100% selectivity and remarkable stability for CO 2 electroreduction to CO, exceeding most reported state-of-the-art catalysts. Specifically, the CO Faradaic efficiency (FE CO ) maintains above 90% over a broad potential range (-0.55 to -0.95 V vs. RHE) and reaches a maximum value of 99.6% at a relatively low potential of -0.67 V. More importantly, the FE CO is kept above 95% within a long-term 100 h electrolyzing. Density functional theory (DFT) calculations explain the high selectivity for CO generation is due to the high energy barrier required for hydrogen evolution on the unsaturated Ni-N 3 . This work provides a new designing strategy for the construction of ultrastable and highly selective single-atom catalysts for efficient CO 2 conversion., (© 2023 Wiley‐VCH GmbH.)