Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries

This paper presents a review of living radical polymerization achieved with thiocarbonylthio compounds [ZC(=S)SR] by a mechanism of reversible addition–fragmentation chain transfer (RAFT). Since we first introduced the technique in 1998, the number of papers and patents on the RAFT process has increased exponentially as the technique has proved to be one of the most versatile for the provision of polymers of well defined architecture. The factors influencing the effectiveness of RAFT agents and outcome of RAFT polymerization are detailed. With this insight, guidelines are presented on how to conduct RAFT and choose RAFT agents to achieve particular structures. A survey is provided of the current scope and applications of the RAFT process in the synthesis of well defined homo-, gradient, diblock, triblock, and star polymers, as well as more complex architectures including microgels and polymer brushes.

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Living radical polymerization by the RAFT process

Three-dimensional (3D) N-doped graphene aerogel (N-GA)-supported Fe3O4 nanoparticles (Fe3O4/N-GAs) as efficient cathode catalysts for the oxygen reduction reaction (ORR) are reported. The graphene hybrids exhibit an interconnected macroporous framework of graphene sheets with uniform dispersion of Fe3O4 nanoparticles (NPs). In studying the effects of the carbon support on the Fe3O4 NPs for the ORR, we found that Fe3O4/N-GAs show a more positive onset potential, higher cathodic density, lower H2O2 yield, and higher electron transfer number for the ORR in alkaline media than Fe3O4 NPs supported on N-doped carbon black or N-doped graphene sheets, highlighting the importance of the 3D macropores and high specific surface area of the GA support for improving the ORR performance. Furthermore, Fe3O4/N-GAs show better durability than the commercial Pt/C catalyst.

3D Nitrogen-Doped Graphene Aerogel-Supported Fe3O4 Nanoparticles as Efficient Electrocatalysts for the Oxygen Reduction Reaction

Two-photon excitation provides a means of activating chemical or physical processes with high spatial resolution in three dimensions and has made possible the development of three-dimensional fluorescence imaging, optical data storage, and lithographic microfabrication. These applications take advantage of the fact that the two-photon absorption probability depends quadratically on intensity, so under tight-focusing conditions, the absorption is confined at the focus to a volume of order λ3 (where λ is the laser wavelength). Any subsequent process, such as fluorescence or a photoinduced chemical reaction, is also localized in this small volume. Although three-dimensional data storage and microfabrication have been illustrated using two-photon-initiated polymerization of resins incorporating conventional ultraviolet-absorbing initiators, such photopolymer systems exhibit low photosensitivity as the initiators have small two-photon absorption cross-sections (δ). Consequently, this approach requires high laser power, and its widespread use remains impractical. Here we report on a class of π;-conjugated compounds that exhibit large δ (as high as 1, 250 × 10−50 cm4 s per photon) and enhanced two-photon sensitivity relative to ultraviolet initiators. Two-photon excitable resins based on these new initiators have been developed and used to demonstrate a scheme for three-dimensional data storage which permits fluorescent and refractive read-out, and the fabrication of three-dimensional micro-optical and micromechanical structures, including photonic-bandgap-type structures.

Two-photon polymerization initiators for three-dimensional optical data storage and microfabrication

Structure and nanostructure in ionic liquids.

Advanced applications of ionic liquids in polymer science

Black phosphorus (BP), a star-shaped two-dimensional material, has attracted considerable attention owing to its unique chemical and physical properties. BP shows great potential in photocatalysis area because of its excellent optical properties; however, its applications in this field have been limited to date. Now, a Z-scheme heterojunction of 2D/2D BP/monolayer Bi2 WO6 (MBWO) is fabricated by a simple and effective method. The BP/MBWO heterojunction exhibits enhanced photocatalytic performance in photocatalytic water splitting to produce H2 and NO removal to purify air; the highest H2 evolution rate of BP/MBWO is 21042 μmol g-1 , is 9.15 times that of pristine MBWO and the NO removal ratio was as high as 67 %. A Z-scheme photocatalytic mechanism is proposed based on monitoring of . O2 - , . OH, NO2 , and NO3 - species in the reaction. This work broadens applications of BP and highlights its promise in the treatment of environmental pollution and renewable energy issues.

Z‐Scheme 2D/2D Heterojunction of Black Phosphorus/Monolayer Bi2WO6 Nanosheets with Enhanced Photocatalytic Activities

The construction of heterostructures is regarded as an excellent strategy to achieve efficient charge separation and improved photocatalytic activity. Herein, a series of Bi2MoO6/ZnO hierarchical heterostructured photocatalysts were synthesized by a solvothermal method. The morphology of Bi2MoO6 grown on the surface of ZnO nanorods could be controlled by adjusting the experimental conditions. The synthesized samples were characterized by various analytical techniques and their photocatalytic performance was evaluated by photocatalytic reduction of Cr(VI) under visible-light irradiation. Compared with those of pure Bi2MoO6 and ZnO, the Bi2MoO6/ZnO composites showed higher photocatalytic activity towards the reduction of Cr(VI). The enhanced photocatalytic activity was mainly attributed to the formation of a heterojunction between Bi2MoO6 and ZnO, which effectively facilitated the separation and transfer of electrons and holes. In addition, the Bi2MoO6/ZnO photocatalysts maintained good stability after three cycles of Cr(VI) photoreduction. A possible photocatalytic mechanism of the as-synthesized composites was proposed.

Fabrication of Bi2MoO6/ZnO hierarchical heterostructures with enhanced visible-light photocatalytic activity

Reversible lithium-ion storage in silver-treated nanoscale hollow porous silicon particles.

Graphene-encapsulated ordered aggregates of Fe3O4 nanoparticles with nearly spherical geometry and hollow interior were synthesized by a simple self-assembly process. The open interior structure adapts well to the volume change in repetitive Li+ insertion and extraction reactions; and the encapsulating graphene connects the Fe3O4 nanoparticles electrically. The structure and morphology of the graphene-Fe3O4 composite were confirmed by X-ray diffraction, scanning electron microscopy, and high-resolution transmission microscopy. The electrochemical performance of the composite for reversible Li+ storage was evaluated by cyclic voltammetry and constant current charging and discharging. The results showed a high and nearly unvarying specific capacity for 50 cycles. Furthermore, even after 90 cycles of charge and discharge at different current densities, about 92% of the initial capacity at 100 mA g–1 was still recoverable, indicating excellent cycle stability. The graphene-Fe3O4 composite is therefore a capab...

Jianmei Lu

Papers

Advanced applications of ionic liquids in polymer science

Z‐Scheme 2D/2D Heterojunction of Black Phosphorus/Monolayer Bi2WO6 Nanosheets with Enhanced Photocatalytic Activities

Fabrication of Bi2MoO6/ZnO hierarchical heterostructures with enhanced visible-light photocatalytic activity

Reversible lithium-ion storage in silver-treated nanoscale hollow porous silicon particles.

Graphene-Encapsulated Hollow Fe3O4 Nanoparticle Aggregates As a High-Performance Anode Material for Lithium Ion Batteries