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Sodium‐ion batteries are promising energy‐storage systems, but they are facing huge challenges for developing fast‐charging anode materials. Bismuth (Bi)‐based anode materials are considered as candidates for fast‐charging anodes of sodium‐ion batteries due to their excellent rate performance. Herein, we designed a two‐dimensional Bi/MXene anode material based on a hydrogen thermal reduction strategy. Benefitting from microstructure advantages, Bi/MXene anodes exhibited an excellent rate capability and superior cycle performance in Na//Bi/MXene half‐batteries and Na3V2(PO4)3/C//Bi/MXene full‐batteries. Moreover, full‐batteries can complete a charge/discharge cycle in 7 min and maintain an excellent cycle life (over 7000 cycles). The electrochemical test results showed that Bi/MXene is a promising anode material with fast charge/discharge capability for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

We discovered that the 2D Ti3C2Tx MXene sheet displays an ultra‐high removal capability for bilirubin (BR). In particular, MXene shows 47.6 times higher removal efficiency over traditional activated carbon absorbents. The effect of MXene on the removal rate of BR in BR solution containing different concentrations of bovine serum albumin (BSA) was studied. The adsorption capacity of BSA for BR at high concentration of 5 g L−1 was about 85% of the best adsorption capacity. The MXene before and after adsorption was characterized by SEM, FT‐IR and XPS. Furthermore, MXene beads were prepared, and the hemoperfusion simulation experiment was carried out. The results show that the adsorption capacity of MXene for bilirubin can reach 1192.9 mg g−1. This study suggests that MXene may be promising in the treatment of hyperbilirubinemia. [ABSTRACT FROM AUTHOR]

Nowadays, an ever‐increasing variety of organic contaminants in water has caused hazards to the ecological environment and human health. Many of them are persistent and non‐biodegradable. Various techniques have been studied for sewage treatment, including biological, physical and chemical methods. Photocatalytic advanced oxidation processes (AOPs) have received increasing attention due to their fast reaction rates and strong oxidation capability, low cost compared with the non‐photolytic AOPs. This review is dedicated to summarizing up‐to‐date research progress in photocatalytic AOPs, such as Fenton or Fenton‐like reaction, ozonation and sulfate radical‐based advanced oxidation processes. Mechanisms and activation processes are discussed. Then, the paper summarizes photocatalytic materials and modification strategies, including defect chemistry, morphology control, heterostructure design, noble metal deposition. The future perspectives and challenges are also discussed. [ABSTRACT FROM AUTHOR]

MXenes represent a category of two‐dimensional functional nanomaterials with remarkable structural and chemical properties, which have been manipulated into different architectures for versatile applications. These manipulation processes generally take place at the interfaces between liquid, solid, and gas; and therefore, the investigation of the interfacial property of MXenes is the key. Here we show that MXenes exhibit amphiphilic behaviours at interfaces. Different from common amphiphiles, MXenes have the dual function of both colloidal and molecular activities owing to their two abrupt structural length scales: their large lateral sheet size allows for behaving like colloidal amphiphiles for creating emulsions, while their small sheet thickness allows for serving as molecular amphiphiles for dispersing solid substances. Further, such dual colloidal‐molecular amphiphility has driven MXenes to accumulate at the interfaces of water and nitrogen gas, and the assembly into thin film electrodes for electrochemical energy storage. All these findings open up enormous opportunities for processing various MXenes‐related functional materials and devices. The dual amphiphilic properties of MXenes at liquid–liquid, liquid–solid, and liquid–gas interfaces are reported. They allow for creating emulsions, dispersing solid substrates, and assembly into thin film electrodes for electrochemical energy storage. [ABSTRACT FROM AUTHOR]

Abstract: Prussian blue and its analogues (PBAs) have been recognized as one of the most promising cathode materials for room‐temperature sodium‐ion batteries (SIBs). Herein, we report high crystalline and Na‐rich Prussian white Na2CoFe(CN)6 nanocubes synthesized by an optimized and facile co‐precipitation method. The influence of crystallinity and sodium content on the electrochemical properties was systematically investigated. The optimized Na2CoFe(CN)6 nanocubes exhibited an initial capacity of 151 mA h g−1, which is close to its theoretical capacity (170 mA h g−1). Meanwhile, the Na2CoFe(CN)6 cathode demonstrated an outstanding long‐term cycle performance, retaining 78 % of its initial capacity after 500 cycles. Furthermore, the Na2CoFe(CN)6 Prussian white nanocubes also achieved a superior rate capability (115 mA h g−1 at 400 mA g−1, 92 mA h g−1 at 800 mA g−1). The enhanced performances could be attributed to the robust crystal structure and rapid transport of Na ions through large channels in the open‐framework. Most noteworthy, the as‐prepared Na2CoFe(CN)6 nanocubes are not only low‐cost in raw materials but also contain a rich sodium content (1.87 Na ions per lattice unit cell), which will be favorable for full cell fabrication and large‐scale electric storage applications. [ABSTRACT FROM AUTHOR]

Antimony/porous biomass carbon nanocomposites have been prepared by a chemical reduction method and applied as anodes for sodium-ion batteries. The porous biomass carbon derived from a black fungus had a large Brunauer-Emmett-Teller (BET) surface area of 2233 m2 g−1 in which antimony nanoparticles were uniformly distributed in the porous carbon. The as-prepared antimony/porous biomass carbon nanocomposites exhibited a high reversible sodium storage capacity of 567 mA h g−1 at a current density of 100 mA g−1, extended cycling stability, and good rate capability. [ABSTRACT FROM AUTHOR]

Na-ion batteries have been attracting intensive investigations as a possible alternative to Li-ion batteries. Herein, we report the synthesis of SnS2 nanoplatelet@graphene nanocomposites by using a morphology-controlled hydrothermal method. The as-prepared SnS2/graphene nanocomposites present a unique two-dimensional platelet-on-sheet nanoarchitecture, which has been identified by scanning and transmission electron microscopy. When applied as the anode material for Na-ion batteries, the SnS2/graphene nanosheets achieved a high reversible specific sodium-ion storage capacity of 725 mA h g−1, stable cyclability, and an enhanced high-rate capability. The improved electrochemical performance for reversible sodium-ion storage could be ascribed to the synergistic effects of the SnS2 nanoplatelet/graphene nanosheets as an integrated hybrid nanoarchitecture, in which the graphene nanosheets provide electronic conductivity and cushion for the active SnS2 nanoplatelets during Na-ion insertion and extraction processes. [ABSTRACT FROM AUTHOR]

The synthesis of nanoporous graphene by a convenient carbon nanofiber assisted self-assembly approach is reported. Porous structures with large pore volumes, high surface areas, and well-controlled pore sizes were achieved by employing spherical silica as hard templates with different diameters. Through a general wet-immersion method, transition-metal oxide (Fe3O4, Co3O4, NiO) nanocrystals can be easily loaded into nanoporous graphene papers to form three-dimensional flexible nanoarchitectures. When directly applied as electrodes in lithium-ion batteries and supercapacitors, the materials exhibited superior electrochemical performances, including an ultra-high specific capacity, an extended long cycle life, and a high rate capability. In particular, nanoporous Fe3O4-graphene composites can deliver a reversible specific capacity of 1427.5 mAh g−1 at a high current density of 1000 mA g−1 as anode materials in lithium-ion batteries. Furthermore, nanoporous Co3O4-graphene composites achieved a high supercapacitance of 424.2 F g−1. This work demonstrated that the as-developed freestanding nanoporous graphene papers could have significant potential for energy storage and conversion applications. [ABSTRACT FROM AUTHOR]

Herein, we report a facile and 'green' synthetic route for the preparation of Ge@C core-shell nanocomposites by using a low-cost Ge precursor. Field-emission scanning and transmission analyses confirmed the core-shell nanoarchitecture of the Ge@C nanocomposites, with particle sizes ranging from 60 to 100 nm. Individual Ge nanocrystals were coated by a continuous carbon layer, which had an average thickness of 2 nm. When applied as an anode materials for lithium-ion batteries, the Ge@C nanocomposites exhibited a high initial discharge capacity of 1670 mAh g−1 and superior rate capability. In particular, Ge@C nanocomposite electrodes maintained a reversible capacity of 734 mAh g−1 after repeated cycling at a current density of 800 mA g−1 over 100 cycles. [ABSTRACT FROM AUTHOR]

Nickel oxide nanosheets have been successfully synthesized by a facile mediated hydrothermal method. The morphology and crystal structure of the nickel oxide nanosheets were characterized by X-ray diffraction, field-emission SEM, and TEM. When applied as electrode materials for lithium-ion batteries and supercapacitors, nickel oxide nanosheets exhibited a high, reversible lithium storage capacity of 1193 mA h g−1 at a current density of 500 mA g−1, an enhanced rate capability, and good cycling stability. Nickel oxide nanosheets also demonstrated a superior specific capacitance of 999 F g−1 at a current density of 20 A g−1 in supercapacitors. [ABSTRACT FROM AUTHOR]

CoFe2O4/multiwalled carbon nanotubes (MWCNTs) hybrid materials were synthesized by a hydrothermal method. Field emission scanning electron microscopy and transmission electron microscopy analysis confirmed the morphology of the as-prepared hybrid material resembling wintersweet flower 'buds on branches', in which CoFe2O4 nanoclusters, consisting of nanocrystals with a size of 5-10 nm, are anchored along carbon nanotubes. When applied as an anode material in lithium ion batteries, the CoFe2O4/MWCNTs hybrid material exhibited a high performance for reversible lithium storage. In particular, the hybrid anode material delivered reversible lithium storage capacities of 809, 765, 539, and 359 mA h g−1 at current densities of 180, 450, 900, and 1800 mA g−1, respectively. The superior performance of CoFe2O4/MWCNTs hybrid materials could be ascribed to the synergistic pinning effect of the wintersweet-flower-like nanoarchitecture. This strategy could also be applied to synthesize other metal oxide/CNTs hybrid materials as high-capacity anode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Sulfur/graphene nanocomposite material has been prepared by incorporating sulfur into the graphene frameworks through a melting process. Field-emission scanning electron microscope analysis shows a homogeneous distribution of sulfur in the graphene nanosheet matrix. The sulfur/graphene nanocomposite exhibits a super-high lithium-storage capacity of 1580 mAh g−1 and a satisfactory cycling performance in lithium-sulfur cells. The enhancement of the reversible capacity and cycle life could be attributed to the flexible graphene nanosheet matrix, which acts as a conducting medium and a physical buffer to cushion the volume change of sulfur during the lithiation and delithiation process. Graphene-based nanocomposites can significantly improve the electrochemical performance of lithium-sulfur batteries. [ABSTRACT FROM AUTHOR]