scholarly journals A facile synthesis of a carbon-encapsulated Fe3O4 nanocomposite and its performance as anode in lithium-ion batteries

2013 ◽  
Vol 4 ◽  
pp. 699-704 ◽  
Author(s):  
Raju Prakash ◽  
Katharina Fanselau ◽  
Shuhua Ren ◽  
Tapan Kumar Mandal ◽  
Christian Kübel ◽  
...  

A carbon-encapsulated Fe3O4 nanocomposite was prepared by a simple one-step pyrolysis of iron pentacarbonyl without using any templates, solvents or surfactants. The structure and morphology of the nanocomposite was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis and Raman spectroscopy. Fe3O4 nanoparticles are dispersed intimately in a carbon framework. The nanocomposite exhibits well constructed core–shell and nanotube structures, with Fe3O4 cores and graphitic shells/tubes. The as-synthesized material could be used directly as anode in a lithium-ion cell and demonstrated a stable capacity, and good cyclic and rate performances.

2019 ◽  
Vol 43 (3-4) ◽  
pp. 135-139
Author(s):  
Pegah Farokhian ◽  
Manouchehr Mamaghani ◽  
Nosrat Ollah Mahmoodi ◽  
Khalil Tabatabaeian ◽  
Abdollah Fallah Shojaie

An efficient protocol for the facile synthesis of a series of pyrido[2,3- d]pyrimidine derivatives has been developed applying Fe3O4–ZnO–NH2–PW12O40 nanocatalyst in water. This novel method has the benefits of operational simplicity, green aspects by avoiding toxic solvents and high to excellent yields of products. Fe3O4–ZnO–NH2–PW12O40 was synthesized and characterized by Fourier transform infrared, X-ray diffraction, vibrating sample magnetometer, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy analyses. The nanocatalyst is readily isolated and recovered from the reaction mixture by an external magnet.


2016 ◽  
Vol 09 (03) ◽  
pp. 1650045 ◽  
Author(s):  
Pei-Ying Li ◽  
Kai-Yu Cheng ◽  
Xiu-Cheng Zheng ◽  
Pu Liu ◽  
Xiu-Juan Xu

Chitosan-ionic liquid conjugation (CILC), which was prepared through the reaction of 1-(4-bromobutyl)-3-methylimidazolium bromide (BBMIB) with chitosan, was firstly used to prepare functionalized graphene composite via the chemical reduction of graphene oxide (GO). The obtained water soluble graphene-based composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectroscopy and so on. CILC-RGO showed excellent dispersion stability in water at the concentration of 2.0 mg/mL, which was stable for several months without any precipitate. This may be ascribed to the electrostatic attraction and [Formula: see text]–[Formula: see text] interaction between CILC and graphene.


2020 ◽  
Vol 98 (12) ◽  
pp. 771-778
Author(s):  
Xin Chang ◽  
Xiangyang Xu ◽  
Zhifeng Gao ◽  
Yingrui Tao ◽  
Yixuan Yin ◽  
...  

A nanocomposite, reduced graphene oxide (RGO) modified ZnCo2O4 (ZnCo2O4–RGO) was synthesized via one-step solvothermal method for activating persulfate (PS) to degrade bisphenol A (BPA). The morphology and structure of the nanocomposite were identified by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. RGO provides nucleation sites for ZnCo2O4 to grow and inhibits the agglomeration of the nanoparticles. The influence of different reaction conditions on the oxidation of BPA catalyzed by ZnCo2O4–RGO was investigated, including the content of RGO, the dosage of catalyst, the concentration of humic acid (HA), anions in the environment, the reaction temperature, and pH. BPA can be totally degraded within 20 min under optimized reaction conditions. The presence of HA, Cl−, and NO3− only has a slight effect on the oxidation of BPA, whereas the presence of either H2PO4− or HCO3− can greatly inhibit the reaction. ZnCo2O4–RGO shows good cycling stability and practical application potential. A reaction mechanism of the degradation of BPA was also explored.


2020 ◽  
Vol 20 (3) ◽  
pp. 1962-1967
Author(s):  
Zhen Liu ◽  
Wei Zhou ◽  
Guilin Zeng ◽  
Yuling Zhang ◽  
Zebin Wu ◽  
...  

Oroxylum as a traditional Chinese medicine, was used as a green and novel bio-template to synthesize tremella-like Li3V2(PO4)3/C composite (LVPC) cathode materials by adopting a facile immersion method. The microstructures were analyzed by X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties were investigated by galvanostatic charge–discharge experiments. The LVPC revealed specific capacity of 95 mAh·g-1 at 1 C rate within potential range of 3.0–4.3 V. After 100 cycles at 0.2 C, the retention of discharge capacity was 96%. The modified electrochemical performance is mainly resulted from the distinct tremella-like structure.


2016 ◽  
Vol 697 ◽  
pp. 706-709
Author(s):  
Ming Gong ◽  
Chang An Wang

V2O5 hollow microspheres were synthesized by a one-step solvothermal method, with the assistance of PVP as the soft template, ethylene glycol (EG) as the solvent, and vanadium (iii) acetylacetonate (acac) as the metal-ions source. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM). The size of V2O5 hollow microspheres, which can be easily tuned by using PVP of different molecular weights, was about 2.5μm, 4.5μm and 6μm when using PVP-K17, PVP-K30 and PVP-K60 as the template, respectively.


2011 ◽  
Vol 233-235 ◽  
pp. 2289-2293
Author(s):  
Pin Jiang Li ◽  
Wen Jun Fa ◽  
Yan Ge Zhang ◽  
Bao Jun Huang ◽  
Yi Dong Zhang

Hairball-like bismuth trisulphide microcrystallines has been successfully prepared via one step solvothermal process and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) techniques. The morphologies of the Bi2S3 microcrystallines were influenced by reaction time, temperature, the mole ratio of the reactants and concentration of starting materials, and the growth process has been proposed. The electrochemical behavior of Bi2S3 was investigated using the cyclic voltammetry.


2020 ◽  
Vol 20 (5) ◽  
pp. 2911-2916
Author(s):  
Zhen Zhang ◽  
Xiao Chen ◽  
Guangxue Zhang ◽  
Chuanqi Feng

The MoO3/V2O5/C, MoO3/C and V2O5/C are synthesized by electrospinning combined with heat treatment. These samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and thermogravimetric analysis (TG) techniques. The results show that sample MoO3/V2O5/C is a composite composed from MoO3, V2O5 and carbon. It takes on morphology of the nanofibers with the diameter of 200~500 nm. The TG analysis result showed that the carbon content in the composite is about 40.63%. Electrochemical properties for these samples are studied. When current density is 0.2 A g−1, the MoO3/V2O5/C could retain the specific capacity of 737.6 mAh g−1 after 200 cycles and its coulomb efficiency is 92.99%, which proves that MoO3/V2O5/C has better electrochemical performance than that of MoO3/C and V2O5/C. The EIS and linear Warburg coefficient analysis results show that the MoO3/V2O5/C has larger Li+ diffusion coefficient and superior conductivity than those of MoO3/C or V2O5/C. So MoO3/V2O5/C is a promising anode material for lithium ion battery application.


2014 ◽  
Vol 496-500 ◽  
pp. 297-300 ◽  
Author(s):  
Bi Tao Liu ◽  
Liang Liang Tian ◽  
Ling Ling Peng

A series of composites of the high photoactivity of {001} facets exposed BiOCl and grapheme sheets (GS) were synthesized via a one-step hydrothermal reaction. The obtained BiOCl/GS photocatalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, transmission electron microscopy (TEM), Ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy. The as-prepared BiOCl/GS photocatalyst showed enhanced photocatalytic activity for the degradation of methyl orange (MO) under UV and visible light (λ > 400 nm). The enhanced photocatalytic activity could be attributed to oxygen vacancies of the {001} facets of BiOCl/GS and the high migration efficiency of photo-induced electrons, which could suppress the charge recombination effectively.


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