Light Scattering and Enhanced Photoactivities of Electrospun Titania Nanofibers

Titania nanofibers with fiber diameters ranging from 194 to 441 nm were electrospun as light-scattering photoactive materials. Transmittance UV-vis spectroscopy revealed that the scattering behavior of these samples was linearly proportional to the fiber diameter and the fiber deposition density, which is in agreement with a scattering model based on the Mie theory. The photocurrent- voltage characteristics of the nanostructured samples with a scattering band that overlapped with the absorption band of titania demonstrated a photocurrent that increased steadily with the fiber deposition density. Scattering-enhanced superior photocurrent was found to be 4.8 times higher than that of other samples without direct overlapping between the scattering and absorption bands. Photocatalytic hydrogen evolution under UV irradiation was associated with a similar increase in scattering. The optimized hydrogen evolution rate was 34.9 mu mol/g.cm(2).h, which was more than two times higher than that for other samples that had less scattering.