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• Single-atomic electrocatalyst with abundant Ni-N 4 active sites is developed via NH 4 Cl-assited pyrolysis method. • High catalytic performance with CO Faradaic efficiency of 98% is observed at a small overpotential of 510 mV. • Optimized mesopore size, increased concentrations of Ni-N 4 active sites and pyridinic N species are achieved by NH 4 Cl addition. • Unveiling the synergistic catalytic effect of Ni-N 4 active sites and pyridinic N species in catalyzing CO 2 reduction. Single-atomic transition metal-nitrogen codoped carbon (M-N-C) are efficient substitute catalysts for noble metals to catalyze the electrochemical CO 2 reduction reaction (CO 2 RR). However, the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N x active sites are frequently observed in the commonly used pyrolysis procedure. Herein, single-atomic nickel (Ni)-based sheet-like electrocatalysts with abundant Ni-N 4 active sites were created by using a novel ammonium chloride (NH 4 Cl)-assited pyrolysis method. Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N 4 structure. The addition of NH 4 Cl optimized the mesopore size to 7–10 nm and increased the concentrations of pyridinic N (3.54 wt%) and Ni-N 4 (3.33 wt%) species. The synergistic catalytic effect derived from Ni-N 4 active sites and pyridinic N species achieved an outstanding CO 2 RR performance, presenting a high CO Faradaic efficiency (FE CO) up to 98% and a large CO partial current density of 8.5 mA cm−2 at a low potential of -0.62 V vs. RHE. Particularly, the FE CO maintains above 80% within a large potential range from -0.43 to -0.73 V vs. RHE. This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO 2 conversion systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Rechargeable batteries play an increasingly important role in the field of energy storage. To further improve battery performances, the controllable construction of heterostructures and superlattices based on existing promising materials is a very important strategy. Among different stacking structures, vertical two-dimensional (2D) heterostructures and superlattices have unique advantages and broad development prospects. This review sheds light on the significance and progress of vertical 2D heterostructures and superlattices for lithium batteries and beyond. It begins by introducing the advantages and classification of heterostructures and superlattices. Subsequently, it thoroughly examines the preparation and characterization methods of vertical 2D heterostructures and superlattices in a controlled manner. The discussion then shifts to the diverse applications of vertical 2D heterostructures and superlattices in various rechargeable batteries. Finally, the challenges and future developments of vertical 2D heterostructures and superlattices for rechargeable batteries are highlighted.

It is always challenging to fabricate two-dimensional transition-metal dichalcogenides into multiple hollow micro-/nanostructures with improved properties for various potential applications. Here, hierarchically porous MoS2–C hollow rhomboids (MCHRs) have been creatively synthesized via a facile self-templated solvothermal approach. It has been clarified that the obtained MCHRs assembled beneath ultrathin γ-MnS and carbon cohybridized MoS2nanosheets under the structural direction of the MnMoO4·0.49H2O self-template. The prepared MCHR anode of sodium-ion batteries exhibited a reversible capacity of 506 mA h g–1at 0.1 A g–1, ultrahigh rate capabilities up to 10 A g–1with 310 mA h g–1, and exceptional stability over 3000 cycles. This study provides inspiration for the rational design of hierarchically porous hollow nanostructures with specific geometries as an excellent electrode material for outstanding performance energy storage equipment.

One major obstacle in the advancement of proton exchange membrane (PEM) technology is the development of highly active and durable electrocatalysts for the oxygen evolution reaction (OER) in an acid environment. In comparison with conventional catalysts in the powdery form, the self-supported nanostructures are more promising for practical applications. However, the preparation of self-supported nanocatalysts with high stability in acidic media remains challenging. Herein, IrOxnanostructures anchored on carbon cloth were prepared by a facile two-step method, which involved a fast dip-coating process and a subsequent annealing treatment under different temperatures. High hydroxide contents and mixed valence of iridium were observed for the obtained samples. By optimizing the annealing temperature, we achieved a low overpotential of 220 mV at the current density of 20 mA cm–2. The optimal activity was attributed to a balance between hydroxide content and electrochemical surface area. Moreover, the self-supported IrOxnanostructure showed a good stability over 50 h.

Rapid deactivation by coke deposition is the main obstacle of ethane aromatization over Zn/ZSM-5. In this work, using the prepared nanosized Zn/HZSM-5, an almost threefold product yield and significantly improved stability were achieved in comparison with those of the microsized catalyst. XRD and XPS analyses indicated that a higher percentage of reactive [ZnOZn]2+species was maintained during ethane aromatization over nano-Zn/HZSM-5 than micro-Zn/HZSM-5. In addition, the evolution of carbon deposits over nanosized and microsized Zn/ZSM-5 was investigated during prolonged ethane aromatization reaction using Raman spectroscopy and thermogravimetry measurements. Compared to the microsized catalyst, the nanosized zeolite facilitated the faster escape of light aromatics and the precursors of carbon deposits from the zeolite pores, thus suppressing the accumulation of coke deposits and improving the catalyst stability. Based on the nanosized Zn/HZSM-5, a protocol of isothermal reaction followed by regeneration was developed by periodically removing carbonaceous deposits, and an ∼25–35% product yield was achieved after 10 reaction–regeneration cycles.

A highly reactive bis-naphthalene tetracarboxylic diimide (bis-NDI) intermediate, TBrDNDI, was designed and synthesized for core-expanded NDIs. Based on this intermediate, we achieved 9- and 11-membered core-expanded bis-NDI derivatives. Through expanding the NDI core and introducing electron-donor or electron-acceptor groups, the frontier energy orbitals, optical and electrical properties of these bis-NDIs can be finely tuned to obtain air-stable ambipolar or n-type materials.

The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect of interlayer distance of layered double hydroxides (LDHs) on pseudocapacitors. Here, we obtained the CoAl–LDH with different interlayer distance via the reaction in aqueous media hydrothermally. Electrochemical characterization reveals that the CoAl(DS–(dodecyl sulfate))–LDHs with an interlayer distance of 2.58 nm can deliver higher specific capacitance of 1481.7 F g–1than CoAl(SO42–)–LDH (0.87 nm, 1252.7 F g–1) and CoAl (CO32–)–LDH (0.76 nm, 1149.2 F g–1) at a discharge current density of 1 A g–1. An asymmetric supercapacitor with the CoAl(DS–)–LDHs║activated carbon also shows a better electrochemical performance, including a high energy density of 54.2 W h kg–1at a power density of 0.9 kW kg–1and a longterm stability, in comparison with CoAl(SO42–)–LDH and CoAl (CO32–)–LDH║activated carbon. 在电化学储能过程中, 层状结构材料中较窄的层间距一般会抑制电解液离子的嵌入, 进而限制其层间内部结构在电化学储能过程 中的充分利用. 本文分别选用3种不同尺寸的阴离子(CO32–, SO42–, DS–(十二烷基硫酸根)), 通过简单的一步水热过程, 成功对CoAl–LDH (层状双羟基复合金属氧化物)进 行插层, 获得了3种具有不同层间距的复合材料: CoAl(CO32–)–LDH (0.76 nm), CoAl(SO42–)–LDH (0.87 nm), CoAl(DS–)–LDHs (2.58 nm). 超级电容器性能研究表明, 在1 A g–1充放电电流密度下, 3种材料单电极比电 容表现出与其层间距大小的一致 性, 即CoAl(DS–)–LDHs (1481.7 F g–1)>CoAl(SO42–)–LDH (1252.7 F g–1)>CoAl(CO32–)–LDH (1149.2 F g–1). 此外, 将3种材料与活性炭(AC) 组 建非对称超级电容器, 结果表明: 基于电极材料总质量, CoAl(DS–)–LDHs║AC 展现了54.2 W h kg–1的高能量密度和长循环寿命, 且显著高 于CoAl(SO42–)–LDH║AC 和CoAl(CO32–)–LDH║AC 非对称电容器. 该方法为寻找新型高性能超级电容器用层状结构材料提供了新的途径.