Encapsulation of Fe3O4 Nanoparticles into N, S co-Doped Graphene Sheets with Greatly Enhanced Electrochemical Performance

Abstract

Particular N, S co-doped graphene/Fe3O4 hybrids have been successfully synthesized by the combination of a simple hydrothermal process and a subsequent carbonization heat treatment. The nanostructures exhibit a unique composite architecture, with uniformly dispersed Fe3O4 nanoparticles and N, S co-doped graphene encapsulant. The particular porous characteristics with many meso/micro holes/pores, the highly conductive N, S co-doped graphene, as well as the encapsulating N, S co-doped graphene with the high-level nitrogen and sulfur doping, lead to excellent electrochemical performance of the electrode. The N-S-G/Fe3O4 composite electrode exhibits a high initial reversible capacity of 1362.2 mAhg−1, a high reversible specific capacity of 1055.20 mAhg−1 after 100 cycles, and excellent cycling stability and rate capability, with specific capacity of 556.69 mAhg−1 when cycled at the current density of 1000 mAg−1, indicating that the N-S-G/Fe3O4 composite is a promising anode candidate for Li-ion batteries.

Chitosan overlaid Fe3O4/rGO nanocomposite for targeted drug delivery, imaging, and biomedical applications

“…The intermediate region of Fe 3 O 4 , CS, and rGO was uniformly and tightly attached to the rGO sheet's surface, as shown in the HR-TEM images presented in Fig. 4 C. The rGO/Fe 3 O 4 /CS (15%) composites' lattice spacing was measured as 0.25 nm, which corresponds to the (311) plane of the Fe 3 O 4 crystal system face-centered cubic system, as shown in the HR-TEM images 27 . The selected area electron diffraction further investigated the crystalline morphology of Fe 3 O 4 NPs incorporated in the nanocomposite (15%).…”

Fabrication of Fe3O4 Dots Embedded in 3D Honeycomb‐Like Carbon Based on Metallo–Organic Molecule with Superior Lithium Storage Performance

“…Figure g is local magnification of the rectangle area in Figure f, in which lots of small dots can be found. According to high‐resolution TEM image of Figure h, the diameter of small dots is ≈3 nm, which is lower than that of most current Fe 3 O 4 /C composites . The crystal phase of small dots were confirmed by X‐ray diffraction (XRD) pattern, in which typical diffraction peaks at 30.4, 35.4, 43.5, 53.8, 56.9, and 62.7° appear, corresponding to the crystal planes of (220), (331), (400), (422), (511), and (440) of Fe 3 O 4 ( Figure a, JCPDS Card No.…”

“…A typical example of electrostatic attraction is graphene oxide, on the surface of which is full of oxygen‐containing groups with strong electronegativity, and then metal cations or nanoparticles could be anchored by electrostatic interaction. Based on this principle, plenty of carbon/MO x composites involving G/Fe 3 O 4 , G/SnO 2 , G/NiO, and G/MnO 2, have been obtained. Because of intrinsic characterization of graphene, these composites always have very thin sheet‐like morphology and present improved electrochemical properties.…”

First Report on High Entropy Alloy Nanoparticle Decorated Graphene

“…Common methods used for synthesizing graphene reinforced metal/polymer matrix composites are electrodeposition technique 19 , 20 which involves dispersion of graphene in the electrolyte bath used for electrodeposition, powder metallurgy 21 , 22 technique in which graphene is initially mixed with mechanically milled powder followed by compaction and sintering of the polymer/metal powder-graphene mixture, stir casting 23 technique in which graphene is added into molten metal or polymer slurry under stirring condition followed by casting in a mold. Common methods used for synthesizing graphene based composites in which graphene forms the support over which nano-sized solids are attached are mechanical-milling 24 – 28 , solvothermal process 29 , hydrothermal process 30 , 31 , two-steps hydrothermal and solvothermal process 32 , polyol method 33 , sol-gel method 34 , pulsed laser ablation 35 , in-situ electrochemical polymerization method 36 , ex-situ method involving attachment of metallic nanoparticles to the surface of graphene sheets by covalent or non-covalent interactions 37 .…”