Incorporation of Vanadium Oxide in Silica Nanofiber Mats via Electrospinning and Sol‐Gel Synthesis

Abstract

Submicron scale vanadia/silica hybrid nanofiber mats have been produced by electrospinning silica sol-gel precursor containing vanadium oxytriisopropoxide (VOTIP), followed by calcinations at high temperature. The properties of the resulting inorganic hybrid nanofiber mats are compared to those of electrospun pure silica nanofibers. SEM images show fibers are submicron in diameter and their morphology is maintained after calcination. Physisorption experiments reveal that silica nanofiber mats have a high specific surface area of 63 m 2 /g. FT-IR spectra exhibit Si O vibrations and indicate the presence of V 2 O 5 in the fibers. XPS studies reveal that the ratio of Si to O is close to 0.5 on the surface of fibers and the amount of vanadium on the surface of fibers increases with calcination. XRD diffraction patterns show that silica nanofibers are amorphous and orthorhombic V 2 O 5 crystals have formed after calcination. EFTEM images demonstrate the growth of crystals on the surface of fibers containing vanadium after calcination. SEM images of fibers with high-vanadium content (50 mol% V : Si) show that vanadia crystals are mostly aligned along the fiber axis. XPS shows an increase in vanadium contents at the surface, and XRD patterns exhibit an increase in the degree of crystallinity. A coaxial electrospinning scheme has successfully been employed to selectively place V 2 O 5 in the skin layer.

Electrospun Nanofibers: From Rational Design, Fabrication to Electrochemical Sensing Applications

“…Only a few types of inorganic fibers could be obtained by carefully selecting metallic precursors and solvents [47][48][49]. Recent studies demonstrated that the combination of electrospinning and sol-gel process could be used for direct producing inorganic fibers, for example TiO 2 /SiO 2 and Al 2 O 3 [50], SiO 2 [51], V 2 O 5 /SiO 2 [52], SiO 2 /ZrO 2 [53]. The key point of this method was to control the hydrolysis rate of sol-gel precursors by adjusting the pH value or aging conditions.…”

Synthesis of Highly Crystalline Hollow TiO2 Fibers Using Atomic Layer Deposition on Polymer Templates

“…The oily core was extracted with octane, producing hollow fibers after suitable calcination. After this work, synthesis of hollow fibers of various oxide materials including TiO 2 , Fe 2 O 3 , LiCoO 2 , and VO 2 has been reported by other research groups …”

“…After this work, synthesis of hollow fibers of various oxide materials including TiO 2 , Fe 2 O 3 , LiCoO 2 , and VO 2 has been reported by other research groups. [12][13][14][15] Hollow oxide fibers synthesized by this one-step electrospinning with a specially designed core-shell needle are polycrystalline in nature. Individual fibers consist of small grains that are randomly oriented.…”

Synthesis of titanium carbide–carbon nanofibers via carbothermal reduction of titania with carbon

“…Although most of electrospinning has focused on the synthesis of nanoscale polymeric materials, inorganic nanofibers such as silica have also been synthesized by electrospinning their precursors, followed by thermal treatment [13,14]. Precursors of metal oxides such as TiO 2 , V 2 O 5 and Fe 3 O 4 have successfully been incorporated into electrospun inorganic silica or carbon nanofibers [15][16][17][18]. In addition, electrospinning and self-assembly of block copolymers have been utilized in controlling dispersion of metal oxide nanoparticles in electrospun nanofibers [19].…”