Ag or Au Nanoparticle-Embedded One-Dimensional Composite TiO₂ Nanofibers Prepared via Electrospinning for Use in Lithium-Ion Batteries

We prepared metallic-nanoparticle-embedded one-dimensional titanium dioxide (1D-TiO 2 ) via a one-step electrospinning process, in which Au or Ag metallic nanoparticles between 5 and 10 nm in diameter were incorporated within the TiO 2 nanofibers. After calcination of the composite nanofibers at high temperature of 450 °C, the nanofibers were converted to 1D-TiO 2 by the thermal decomposition of polyvinylpyrrolidone (PVP). This process simultaneously changed the metal precursors (AgNO 3 or HAuCl 4 ·3H 2 O) to metallic nanoparticles (Ag or Au) to produce 1D-TiO 2 nanofiber composites (Ag@1D-TiO 2 or Au@1D-TiO 2 ). The influences of Ag or Au incorporation into the 1D-TiO 2 nanofibers were studied using various microscopic and X-ray spectroscopic methods. Because of the changes in crystallinity and size of TiO 2 in the Ag@1D-TiO 2 and Au@1D-TiO 2 nanostructures, lithium-ion diffusion and charge transfer were promoted. In particular, in comparison to pristine 1D-TiO 2, the specific capacity of metal nanoparticle-embedded 1D-TiO 2 nanofiber composites was increased by at least 20%, and the rate performance was improved 2-fold. Consequently, we propose that these metal-nanoparticle-embedded 1D-nanostructures prepared via electrospinning may be useful as electrodes in lithium-ion batteries.