Facile fabrication of transparent TiO2-C@TiO2-C free-standing film for visible-light photocatalytic application

Abstract A transparent TiO 2 -C@TiO 2 -C free-standing film has been synthesized by two-step hydrothermal method and subsequent thermal annealing. The chemical composition and morphological features of the TiO 2 -C@TiO 2 -C film are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and N 2 adsorption-desorption measurement. The results indicate that the flower-like micro/nanostructure TiO 2 -C particle layers are intimately inhered to porous TiO 2 -C fibers. The fibers in film are interconnected each other to form a three-dimensional reticulate microstructure, and exhibit intense visible light absorption and high adsorptivity of dye molecules. The interaction between TiO 2 and its surface carbon layer in TiO 2 -C particle promotes the generation of Ti- O -C bonds, which leads to effective charge transfer. Under visible-light irradiation, TiO 2 -C@TiO 2 -C film presents enhanced photocatalytic activity for degradation of methylene blue. This work may provide a new viewpoint for designing transparent photocatalytic film for promising applications in heterogeneous photocatalysis.