Ultrasmall SnFe2O4 nanoparticles anchored on N-doped carbon nanofibers for ultralight and high-performance microwave absorption.

One-dimensional (1D) N-doped carbon nanofibers decorated with ultrafine (∼4.5 nm) SnFe2O4 nanoparticles (denoted as SFO/N-CNFs) are successfully synthesized by a combination of electrospinning and solvothermal process, and their microwave absorption (MA) properties are reported for the first time. With only 5 wt% filler loading in a silicone rubber matrix, the optimum reflection loss (RL) could reach -46.5 dB and the qualified frequency bandwidth (RL < -10 dB) can be capable of 4.8 GHz at 1.6 mm, exhibiting better comprehensive absorption performance relative to other analogous absorbers. The lightweight and highly efficient MA of SFO/N-CNFs is largely ascribed to the improved impedance matching and satisfactory attenuation ability caused by the synergistic effect between the ultrasmall-sized SFO nanoparticles (NPs) and 1D N-CNF matrix. This work not only offers a novel and promising high-performance microwave absorber, but also offers a general approach to designing and fabricating ultrasmall transition metal oxide nanoparticle decorated carbon-based composite nanostructures for multifunctional applications.

Fe2P nanoparticle-decorated carbon nanofiber composite towards lightweight and highly efficient microwave absorption.

An Fe2P nanoparticle (Fe2P NP)-decorated carbon nanofiber (represented as Fe2P@CNF) composite was in situ prepared by electrospinning and subsequent high-temperature treatment. Benefitting from the synergy effect between Fe2P NPs and CNFs, as well as improved interface polarization and impedance matching, the Fe2P@CNF composite exhibits excellent microwave absorption performance relative to pure CNFs, in which the Fe2P@CNF composite with a fill loading of only 10 wt% possesses a minimum reflection loss (RL) of -49.2 dB at 3.0 mm and a maximum effective absorption bandwidth of 6.0 GHz at 2.2 mm. Therefore, this work provides a promising approach for the design and synthesis of an Fe2P@CNF composite with high-performance microwave absorption.

Enhanced electrochemical performances based on ZnSnO3 microcubes functionalized in-doped carbon nanofibers as free-standing anode materials.

The binary composite, ZnSnO3 microcubes (ZSO MC) homogeneously parceled in an N-doped carbon nanofiber membrane (ZSO@CNFM), was synthesized via a mild hydrothermal, electrospinning and carbonization process as a flexible lithium-ion battery (LIB) anode material. The unique carbon-coating layer architecture of ZSO@CNFM not only plays a crucial role in alleviating the volume change of ZSO MC during lithium ion insertion/extraction processes, but also constructs a three-dimensional (3D) transport network with the help of interconnected carbon nanofibers (CNFs) to ensure the structural integrity of the material and promote the electrochemical reaction kinetics. Due to its good flexibility characteristics, the as-prepared ZSO@CNFM can be directly adopted as an anode material for LIBs without the use of copper foil, conductive carbon black and any binder. Electrochemical surveying results manifest that the optimal ZSO@CNFM electrode displays excellent cycling stability (582.6 mA h g-1 after 100 lithiation/delithiation cycles at 100 mA g-1), high coulombic efficiency (CE, 99.6% at 100th cycles), and superior rate performance (349.5 mA h g-1 at 2 A g-1). The good electrochemical properties can be ascribed to the synergistic effect of the high theoretical specific capacity of ZSO MC, favourable stability of the carbon substrate, the open structure of ZSO@CNFM and the 3D continuous highly conductive framework for rapid electron/ion transfer.

A novel three-dimensional Fe3SnC/C hybrid nanofiber absorber for lightweight and highly-efficient microwave absorption.

3D Fe3SnC/C hybrid nanofibers are proposed as a novel high-performance microwave absorber. At only 20 wt% filler loading, the optimal reflection loss reaches -119.2 dB at 17.1 GHz and the effective absorption bandwidth is 7.4 GHz with a thickness of 2.3 mm, outperforming most of the reported absorbers.

Ultrafine MoO2 nanoparticles encapsulated in a hierarchically porous carbon nanofiber film as a high-performance binder-free anode in lithium ion batteries.

Flexible free-standing hierarchically porous carbon nanofibers embedded with ultrafine (∼3.5 nm) MoO2 nanoparticles (denoted as MoO2@HPCNFs) have been synthesized by electrospinning and subsequent heat treatment. When evaluated as a binder-free anode in Li-ion batteries, the as-obtained MoO2@HPCNFs film exhibits excellent capacity retention with high reversible capacity (≥1055 mA h g-1 at 100 mA g-1) and good rate capability (425 mA h g-1 at 2000 mA g-1), which is much superior to most of the previously reported MoO2-based materials. The synergistic effect of uniformly dispersed ultrasmall MoO2 nanoparticles and a three-dimensionally hierarchical porous conductive network constructed by HPCNFs effectively improve the utilization rate of active materials, enhance the transport of both electrons and Li+ ions, facilitate the electrolyte penetration, and promote the Li+ storage kinetics and stability, thus leading to a greatly enhanced electrochemical performance.