Photoelectron Properties of Multi-Walled and Single-Walled Titania a Nanotubes

Fluorescence, conductivity, photocatalysis, and photoinduced reactions of defects in titanium dioxide (TiO2) nanotubes of various morphologies (single-walled and multi-walled) were studied. It has been established that fluorescence is due to interband recombination of photoexcited charge carriers. It was found that the transport of charge carriers is significantly affected by defects such as Ti3+ centers, which are present in the samples under study, and their activation energies were obtained. The position of the defects energy levels in the band gap of the samples was determined, and their band diagrams were plotted. It has been found that the presence of both donor and acceptor defects in TiO2 nanotubes leads to additional electrons and holes generation during illumination. The data obtained indicate the competitive ability of the prepared samples as photocatalysts.