ABSTRACT
Fe3O4@CNF anode material for Li-ion batteries (LIBs) was designed and fabricated using lyotropic cellulose acetate as the carbon nanofiber (CNF) phase and Fe(acac)3 as the Fe3O4 phase through the electrospinning approach. Because the CNFs could retard the change of Fe3O4 volume during the electrochemical cycling and improve the electrical conductivity and the introduction of Fe3O4 could offer a larger specific surface area and more mesopores to promote electrolyte penetration and Li+ diffusion, the Fe3O4@CNFs electrode showed high reversible capacities (RCs) of 773.6 and 596.5 mAh g-1 after 300 cycles and capacity residuals of 98.0 and 99.0% at high current densities 1 and 2 A g-1, respectively. This simple method to fabricate Fe3O4@CNFs composite as anode material can be widely applied to fabricate metal oxides and bio-carbon composite nanofibers for high-performance energy storage materials.
ABSTRACT
We developed a facile one-pot method to synthesize multishelled hollow mesoporous SiO2 microspheres (HMSs) with controllable interior structures including one-shell, double-shell, and yolk-shell. Single reagent formaldehyde could fully control the morphology of HMSs, in that formaldehyde was crucial to the SiO2 precursor's hydrolysis rate and the template pore size.
ABSTRACT
Graft copolymer starch-graft-polyacrylonitrile (St-g-PAN) was synthesized by homo-grafting acrylonitrile (AN) from water soluble starch as Ce(IV) was used as an initiator. St-g-PAN nanofibers were prepared via electrospinning St-g-PAN solution in dimethyl sulfoxide (DMSO). The effects of the spinning parameters such as flow rate, spinning voltage, and collector distance on the St-g-PAN nanofiber diameter were investigated. Fourier transform infrared spectra (FT-IR), solid-state nuclear magnetic resonance (13C NMR) and scanning electron microscope (SEM) were used to characterize the structure and surface morphology of the nanofibers. The results showed that the nanofiber diameter depended strongly on the processing parameters. Moreover, the nanofiber had good water resistance, biocompatibility, and tensile intensity. As the cyano groups on St-g-PAN nanofibers were transformed to amidoxime groups, the obtained St-g-PAO nanofiber displayed an excellent adsorption ability, with the adsorption of Cr 533.4â¯mg·g-1 at pHâ¯=â¯2.0 as K2Cr2O7 solution 500â¯mg·L-1 in water was used as the adsorption target. Therefore, these St-g-PAN nanofibers may find potential applications in a wide variety of fields such as tissue engineering, pharmaceutics, energy, and environmental science and engineering.
