TiO2 NFs Research Articles

In vitro chondrocyte interactions with TiO2 nanofibers grown on Ti–6Al–4V substrate by oxidation

High density titania nanofiber (TiO2 NFs) arrays were fabricated in situ on a Ti–6Al–4V substrate by a simple oxidation process, and the in vitro cellular response of chondrocytes on the resulting surfaces was evaluated. Results show that the TiO2 nanofibrous substrate triggers enhanced chondrocytes adhesion, proliferation, and production of extracellular matrix (ECM) fibrils compared to untreated substrate. These results suggest that chondrocytes have an affinity to the surface structure produced by the oxidation process and therefore has potential use in implants designed for cartilaginous applications.

Nanosilver‐Decorated TiO2 Nanofibers Coated with a SiO2 Layer for Enhanced Light Scattering and Localized Surface Plasmons in Dye‐Sensitized Solar Cells

Enhanced harvesting of visible light is vital to the development of highly efficient dye-sensitized solar cells (DSSCs). Nanosilver-decorated TiO2 nanofibers (Ag@TiO2 NFs) were synthesized by depositing chemically reduced Ag ions onto the surface of electrospun TiO2 nanofibers (TiO2 NFs). The prepared Ag@TiO2 NFs were coated with SiO2 (SiO2@Ag@TiO2 NFs) by using PVP as coupling agent for protecting corrosion of Ag nanoparticle by I(-)/I3(-) solution. The fabricated SiO2@Ag@TiO2 NFs demonstrated a synergistic effect of light scattering and surface plasmons, leading to an enhanced light absorption. Moreover, an anode consisting of SiO2@Ag@TiO2 NFs incorporating TiO2 nanoparticles (NPs) increased light harvesting without substantially sacrificing dye attachment. The power conversion efficiency increased from 6.8 to 8.7 % for a thick film (10 μm), that is, 28 %. These results suggest that SiO2@Ag@TiO2 NFs are promising materials for enhanced light absorption in dye-sensitized solar cells.

Photo-Kelvin probe force microscopy for photocatalytic performance characterization of single filament of TiO2 nanofiber photocatalysts

This is an in-depth study on the photocatalytic performance characterization for single filament of TiO2 nanofiber photocatalysts by the novel photo-Kelvin probe force microscopy technique (photo-KPFM) and first principles calculations. Three kinds of TiO2 nanofibers: anatase TiO2 nanofibers (anatase TiO2 NFs), nitrogen doped TiO2 nanofibers (N-TiO2 NFs), and nitrogen doped TiO2 nanofibers decorated with platinum nanoparticles (N-TiO2-Pt NFs) were investigated. The N-TiO2-Pt NFs exhibit the largest negative photo surface potential shift (−182 mV) as compared to anatase TiO2 NFs (−29 mV). The first-principles calculations based on density functional theory (CASTEP simulation software) indicate that the significant photo surface potential shift obtained by adding nitrogen and platinum into TiO2 NFs is induced by two mechanisms: (1) enhancement in absorbance to increase exciton generation and (2) decreased charge recombination to increase surface charge. These changes in the photo surface potential of various TiO2 nanofibers are closely correlated with their photocatalytic activity. Thus, this novel photo-KPFM provides a useful technique to easily monitor the photocatalytic capability of materials in the development of high performance photocatalysts.