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Sn-based materials have been expected as promising anodes in lithium-ion batteries (LIBs) owing to the high theoretical specific capacity (over 2 times of graphite), low price and environmentally friendliness. However, the development of Sn-based materials is always restricted by the poor cyclic and rate performance caused by low conductivity. To address these problems, NiO&SnO 2 (NiSnO x) surface oxides overlayer confined Ni 3 Sn 2 particles supported on carbon nanotubes (Ni 3 Sn 2 @NiSnO x /CNT) are fabricated via a simple impregnation-reduction-oxidation method. Noteworthy, such hierarchical composites feature several merits including: (i) the oxides overlayer in-situ generates a nanometric matrix of Li 2 O, which separates the electrolyte from the active anodes, and accelerate lithium extraction from the anode material; (ii) the Ni matrix provides sufficient space to adjust the volume change during lithiation/delithiation processes; (iii) the CNT provides interconnected electronic conductive networks. As LIBs anodes, Ni 3 Sn 2 @NiSnO x /CNT exhibits higher specific capacitance values (1521 mA h g−1), superior rate capability (46% capacity remain at 50 times current amplification) and better cyclic stability (1041 mA h g−1 after 1000 cycles). Relying on the excellent electrochemical performance, the hierarchical Ni 3 Sn 2 @NiSnO x /CNT nanocomposites are considered as a promising anode material for LIBs. • Oxides overlayer confined Ni 3 Sn 2 alloy are fabricated via simple method. • The Ni matrix and oxides overlayer ameliorate electrochemical behavior. • Ni 3 Sn 2 @NiSnO x /CNT exhibits high capacitive contribution. [ABSTRACT FROM AUTHOR]

To achieve high energy density and superior rate capacity of carbon-based supercapacitors, the integration of large specific area, hierarchical porous structure and abundant heteroatom doping is considered to be a powerful engineered strategy. Unfortunately, such porous carbon materials with multiple synergistic effects are difficult to be achieved simultaneously by conventional synthesis methods in few steps. Herein, we report a series of micro-dominant hierarchical porous carbon with rich heteroatom doping amounts derived by hypercrosslinked polymerization approach for high-performance supercapacitors. Among them, the N/S co-doped porous carbon (N, S-MC) exhibits a micro-dominant (77.5%) hierarchical porous structure, a large surface area (1339 m2 g−1), and rich heteroatom doping amount (4.5% for N, 5.8% for S). Remarkably, the N, S-MC (symmetric capacitors in two-electrode system) delivers a specific capacitance as high as 464 F g−1 at 0.2 A g−1, hence a high energy density of 16.2 W h kg−1 at 50 W kg−1. Meanwhile, the capacitance retention of N, S-MC remains over 92% after 10,000 cycles. This work reports a hypercrosslinked polymerization approach to construct hierarchical porous N, S co-doped carbon for high-performance supercapacitor device, which is look forward to provide a new strategy to prepare carbon-based materials for ultrafast electron/ion transport supercapacitors. In this manuscript, we demonstrate a facial cationic hypercrosslinked polymerization strategy and achieve a perfect phase transformation from 0 D micro-molecule monomer to 3 D hypercrosslinked polymers, with further activation and annealing treatment, the micro-dominant porous carbon with abundant N, S doping (N, S-MC) is well achieved. Based on the excellent electrochemical performance and ultrafast electron/ion diffusion rate, the N, S-MC are considered as a promising electrode for supercapacitors. Image 1 • Microporous structure is simultaneously generated accompany with the hypercrosslinked polymerization. • Hierarchical porous structure attributing to fast electron/ion transport. • Ultrahigh specific surface area, supplying more active sites and pathway for ions diffusion. • N, S doping enhancing considerable pseudo-capacitance and surface wettability. [ABSTRACT FROM AUTHOR]

Iron corrosion is always harmful to our industrial manufacture and thus numerous effects have been conducted for corrosion protection. However, the detrimental corrosion may be applied to produce serviceable materials, resulting in "upcycling waste into wealth". Herein, a novel corrosion engineering is employed to fabricate hierarchical iron rusts/Ni(OH) 2 nanosheet-on-microsphere arrays as effective oxygen evolution reaction (OER) electrocatalysts. Through physically mixing the fabricated ultrathin iron rusts with Ni(OH) 2 microspheres, the as-prepared catalyst requires an overpotential of only 318 mV to achieve the current density of 20 mA cm−2. Besides, negligible increasement of overpotential is observed after continuous chronopotentiometric determination for 30 h. The excellent OER property is attributed to the formed oxygen bridges of Fe–O–Ni on the solid-solid contact sites, which promote oxidation of Ni2+ specieses via the interfacial Fe3+ of iron rusts (FeOOH). In particular, a large-scale production of 2.968 g iron rusts/Ni(OH) 2 catalysts was successfully prepared by using this simple, lowcost yet valid corrosion engineering. This work provides a novel avenue towards large-scale production of efficient OER catalysts by combing with corrosion science, which is beneficial for boosting the progress of water splitting. The achieved hierarchical iron rusts/Ni(OH) 2 nanosheet-on-microsphere arrays exhibit excellent OER activity owing to the promoted oxidation of interfacial Ni2+ specieses by the formed oxygen bridges of Fe–O–Ni on the solid-solid contact sites. Image 1 • Corrosion engineering is employed to fabricate iron rusts/Ni(OH) 2 catalyst for OER. • Hierarchical nanosheet-on-microsphere arrays were achieved by physical mixing. • The excellent OER is attributed to the Fe–O–Ni on the solid-solid contact sites. • A large-scale production of 2.968 g catalysts was successfully prepared. [ABSTRACT FROM AUTHOR]

Exploring high-efficient non-noble metal hydrogen evolution reaction (HER) electrocatalysts is still a challenge for high purity hydrogen producing. The sluggish water dissociation kinetics (Volmer step) in alkaline electrolyte results in poorer HER activities than that in acid media. In this work, an efficient strategy to accelerate the Volmer step in alkaline media is proposed through the synergistic effect between metal and metal oxide. A hybrid catalyst composed of Ni/MoO 2 was prepared by using a facile hydrothermal-reduction method. The metal nickel acts as the adsorption site for hydrogen, while MoO 2 promotes the dissociation of water molecules and optimizes the Ni–H bond energy. In addition, the nanosheet structure is beneficial for exposing more active sites. Electrochemical test reveals that the Ni/MoO 2 catalyst exhibits outstanding HER performance with a small overpotential of 40 mV to deliver the current density of 10 mA cm−2 as well as excellent stability. Hydrogen oxidation reaction (HOR) experiment was performed to study the mechanistic insights into the activity enhancement. Ni/MoO 2 hybrid catalyst with excellent HER performance in alkaline media was prepared by using a facile hydrothermal-reduction method. HOR test demonstrated that the MoO 2 accelerated the OH adsorption thus the Volmer step, which corresponding to the main reason for performance improvement. Image 1 • High efficient catalyst for hydrogen evolution reaction (HER) composed of Ni/MoO 2 was prepared by using a facile hydrothermal-reduction method. • The MoO 2 favors the adsorption and dissociation of water molecules. • Hydrogen oxidation reaction (HOR) test was performed to study the mechanistic insights into the activity enhancement. [ABSTRACT FROM AUTHOR]