Developing nonprecious oxygen evolution electrocatalysts that can work well at large current densities is of primary importance in a viable water‐splitting technology. Herein, a facile ultrafast (5 ...s) synthetic approach is reported that produces a novel, efficient, non‐noble metal oxygen‐evolution nano‐electrocatalyst that is composed of amorphous Ni–Fe bimetallic hydroxide film‐coated, nickel foam (NF)‐supported, Ni3S2 nanosheet arrays. The composite nanomaterial (denoted as Ni‐Fe‐OH@Ni3S2/NF) shows highly efficient electrocatalytic activity toward oxygen evolution reaction (OER) at large current densities, even in the order of 1000 mA cm−2. Ni‐Fe‐OH@Ni3S2/NF also gives an excellent catalytic stability toward OER both in 1 m KOH solution and in 30 wt% KOH solution. Further experimental results indicate that the effective integration of high catalytic reactivity, high structural stability, and high electronic conductivity into a single material system makes Ni‐Fe‐OH@Ni3S2/NF a remarkable catalytic ability for OER at large current densities.
An ultrafast (5 s) synthetic approach that produces a novel, nonprecious oxygen‐evolution electrocatalyst comprising a 3D hierarchical core@shell Ni‐Fe‐OH@Ni3S2 nanostructure supported on nickel foam is presented. The material integrates the structural and catalytic advantages of amorphous Ni–Fe–OH and Ni3S2 nanosheet arrays, possessing an excellent ability to efficiently and stably electrocatalyze the oxygen evolution reaction at large current densities.
Superefficient water‐splitting materials comprising sub‐nanometric copper clusters and quasi‐amorphous cobalt sulfide supported on copper foam are reported. While working together at both the anode ...and cathode sides of an alkaline electrolyzer, this material gives a catalytic output of overall water splitting comparable with the Pt/C–IrO2‐coupled electrolyzer.
Sodium‐ion batteries (SIBs) are considered as promising alternatives to lithium‐ion batteries (LIBs) for large‐scale electrical‐energy‐storage applications due to the wide availability and the low ...cost of Na resources. Along with the avenues of research on flexible LIBs, flexible SIBs are now being actively developed as one of the most promising power sources for the emerging field of flexible and wearable electronic devices. Here, the recent progress on flexible electrodes based on metal substrates, carbonaceous substrates (i.e., graphene, carbon cloth, and carbon nanofibers), and other materials, as well as their applications in flexible SIBs, are summarized. Also, some future research directions for constructing flexible SIBs are proposed, with the aim of providing inspiration to the further development of advanced flexible SIBs.
Flexible sodium‐ion batteries (SIBs) are being actively developed as one of the most promising power sources for the emerging field of flexible and wearable electronic devices. The recent progress on flexible electrodes based on metal substrates, carbonaceous substrates, and other materials, is summarized, along with their applications in flexible SIBs.
The electrochemical N2 fixation, which is far from practical application in aqueous solution under ambient conditions, is extremely challenging and requires a rational design of electrocatalytic ...centers. We observed that bismuth (Bi) might be a promising candidate for this task because of its weak binding with H adatoms, which increases the selectivity and production rate. Furthermore, we successfully synthesized defect‐rich Bi nanoplates as an efficient noble‐metal‐free N2 reduction electrocatalyst via a low‐temperature plasma bombardment approach. When exclusively using 1H NMR measurements with N2 gas as a quantitative testing method, the defect‐rich Bi(110) nanoplates achieved a 15NH3 production rate of 5.453 μg mgBi−1 h−1 and a Faradaic efficiency of 11.68 % at −0.6 V vs. RHE in aqueous solution at ambient conditions.
Beneficial defects: Defect‐rich bismuth nanoplates achieve a 15NH3 production rate of 5.453 μg mgBi−1 h−1 and a Faradaic efficiency of 11.68 % at −0.6 V vs. RHE in aqueous solutions at ambient conditions because of their poor binding with H adatoms, which increases the selectivity and production rate. Also, 1H NMR measurements with N2 gas ware used as a quantitative test method in aqueous electrolytes.
A flexible and wearable lithium–oxygen (air) battery inspired by Chinese bamboo slips is constructed. In this novel battery, cathodes and anodes are woven without an air diffusion layer and any outer ...packaging; besides, the woven structure allows oxygen to access the cathodes from both sides freely, endowing the battery with a record energy density of over 523 W h kg−1.
With the rising demand for flexible and wearable electronic devices, flexible power sources with high energy densities are required to provide a sustainable energy supply. Theoretically, ...rechargeable, flexible Li‐O2/air batteries can provide extremely high specific energy densities; however, the high costs, complex synthetic methods, and inferior mechanical properties of the available flexible cathodes severely limit their practical applications. Herein, inspired by the structure of human blood capillary tissue, this study demonstrates for the first time the in situ growth of interpenetrative hierarchical N‐doped carbon nanotubes on the surface of stainless‐steel mesh (N‐CNTs@SS) for the fabrication of a self‐supporting, flexible electrode with excellent physicochemical properties via a facile and scalable one‐step strategy. Benefitting from the synergistic effects of the high electronic conductivity and stable 3D interconnected conductive network structure, the Li‐O2 batteries obtained with the N‐CNTs@SS cathode exhibit superior electrochemical performance, including a high specific capacity (9299 mA h g−1 at 500 mA g−1), an excellent rate capability, and an exceptional cycle stability (up to 232 cycles). Furthermore, as‐fabricated flexible Li‐air batteries containing the as‐prepared flexible super‐hydrophobic cathode show excellent mechanical properties, stable electrochemical performance, and superior H2O resistibility, which enhance their potential to power flexible and wearable electronic devices.
Inspired by blood capillary tissue, a self‐standing, flexible N‐CNTs@SS Li‐O2 battery cathode with an interpenetrative structure is fabricated via a facile and scalable one‐step strategy. The flexible Li‐O2 batteries with N‐CNTs@SS exhibit excellent mechanical properties, stable electrochemical performance, and superior H2O resistibility.
Nanoscale inorganic wheel-shaped structures are one of the most striking types of molecular aggregations. Here, we report the synthesis of a gigantic lanthanide wheel cluster containing 140 Gd3+ ...atoms. As the largest lanthanide cluster reported thus far, {Gd 140 } features an attractive wheel-like structure with 10-fold symmetry. The nanoscopic molecular wheel possesses the largest diameter of 6.0 nm and displays high stability in solution, which allows direct visualization by scanning transmission electron microscopy. The newly discovered lanthanide {Gd 140 } cluster represents a new member of the molecular wheel family.
The performance of electrode material is correlated with the choice of electrolyte, however, how the solvation has significant impact on electrochemical behavior is underdeveloped. Herein, ...N‐heteropentacenequinone (TAPQ) is investigated to reveal the solvation effect on the performance of sodium‐ion batteries in different electrolyte environment. TAPQ cycled in diglyme‐based electrolyte exhibits superior electrochemical performance, but experiences a rapid capacity fading in carbonate‐based electrolyte. The function of solvation effect is mainly embodied in two aspects: one is the stabilization of anion intermediate via the compatibility of electrode and electrolyte, the other is the interfacial electrochemical characteristics influenced by solvation sheath structure. By revealing the failure mechanism, this work presents an avenue for better understanding electrochemical behavior and enhancing performance from the angle of solvation effect.
N‐heteropentacenequinone (TAPQ) is studied as electrode material to investigate the solvation effect in different sodium‐ion battery electrolytes. By revealing the failure mechanism of TAPQ in carbonate‐based electrolytes, we discuss how the solvation effect influences interfacial electrochemical characteristics and attributed the electrolyte compatibility to the stabilization effect of reaction intermediate via solvation effect.
In recent years, advances in novel photosensitive materials have been expected to drive the development of next-generation smart devices, especially in the field of high visible-light utilization. ...Limited by synthetic techniques, the development of sensitive photoresponsive materials driven by visible light has been slow, especially as the distribution of strictly ordered photoresponsive groups cannot be solved. Here, we report the synergistic construction of a photosensitive metal-organic framework (MOF) consisting of uniform photoresponsive groups. By means of two photoactive units and D-A-D characteristics, short-range photo-generated electron transfer (PET) efficiency is ensured; by virtue of lophine, radical-induced photochromism is generated; thanks to the spatial confinement effect of Zr-MOF and the affinity of the anthracene ring toward singlet oxygen, unlike the previously reported dimerization reaction, the photochemical polymerization of adjacent anthracene rings can be monitored
via
SCXRD, clearly illustrating the detailed mechanism of visible-light-etching at the nanoscale. The occurrence of polymerization not only induces a contraction of the framework, but also improves the long-range PET and overall photon utilization, which is also demonstrated by the effective photocatalytic activation of C(sp
3
)-H and construction of C-N. The related results demonstrate that exploiting the structural tailoring of MOF can provide valuable insights into the development of highly sensitive visible-light-driven lithography designs.
By utilizing an organic linker containing two photoactive groups, Zr-MOF with multiple photofunctionalities, such as photochromism, photo-induced structural transformation, and photo-catalysis, has been explored.
N-Glycosylated heterocycles play important roles in biological systems and drug development. The synthesis of these compounds heavily relies on ionic N-glycosylation, which is usually constrained by ...factors such as labile glycosyl donors, precious metal catalysts, and stringent conditions. Herein, we report a dehydroxylative radical method for synthesizing N-glycosides by leveraging copper metallaphotoredox catalysis, in which stable and readily available 1-hydroxy carbohydrates are activated for direct N-glycosylation. Our method employs inexpensive photo- and copper- catalysts and can tolerate some extent of water. The reaction exhibits a broad substrate scope, encompassing 76 examples, and demonstrates high stereoselectivity, favoring 1,2-trans selectivity for furanoses and α-selectivity for pyranoses. It also exhibits high site-selectivity for substrates containing multiple N-atoms. The synthetic utility is showcased through the late-stage functionalization of bioactive compounds and pharmaceuticals like Olaparib, Axitinib, and Metaxalone. Mechanistic studies prove the presence of glycosyl radicals and the importance of copper metallaphotoredox catalysis.
