High-Efficient Photocatalytic Performance under Visible Light of Functionalized TiO2 Nanofibers via Steam and Pressure Co-Modification

Surface structure plays a key role on the sensitization process. Mesoporous TiO2 nanofibers with high surface area and improved dye coupling mode were successfully fabricated via a simple, template-free, and effective water steam and pressure co-modified route. Compared with the commercial P-25, the modulated surface structure and efficient coupling interaction with a sensitized dye promoted the electron transfer from visible-light-excited chromophores of the dye to the conduction band of TiO2, and thus more than 4 times higher photodegradation of dyes was obtained under visible light (>420 nm). With RhB as a typical dye sensitizer, the photodegradation on other dyes (methyl orange and methylene blue) were all enhanced under visible light. Moreover, the detailed photodegradation mechanism and the coupling mode between the dye and TiO2 were proposed based on the experimental results. The water steam and pressure co-modified strategy could inspire similar attempts to modulate the surface electronic structure and interaction mode of dyes of TiO2 for its applications in environmental, chemical, and biological areas in the future.