Fabrication of Hierarchical V2O5 Nanorods on TiO2 Nanofibers and Their Enhanced Photocatalytic Activity under Visible Light

We report photocatalytic activities of a set of mesoporous, hierarchical nanorods-on-nanofiber heterostructures produced from the organization of vanadium pentoxide (V2O5) nanorods on titanium dioxide (TiO2) nanofibers fabricated using gas jet fiber (GJF) spinning process. The precursor nanofibers spun from solutions of poly(vinylpyrrolidone), titanium tetraisopropoxide, and vanadium oxytriisopropoxide are calcined at 500-600 degrees C in air to yield the above hierarchical nanostructures. The calcination temperature and the composition of the spinning solutions are used as factors to obtain different sizes of the nanorods, nanofibers, and the crystallites. Photocatalytic oxidation of gas-phase ethanol on the heterostructures under visible light at room temperature is studied. The materials calcined at 500 degrees C show oxidation of ethanol into carbon dioxide and water with about three orders of magnitude higher rate than single-component V2O5 nanofibers and reference material V2O5 powder. The higher photocatalytic activity is attributed to the slowdown of the electron-hole charge recombination phenomena in the heterostructures as inferred from photoluminescence study. The heterostructure V2O5-TiO2 photocatalyst can be easily regenerated without sacrificing any photocatalytic performance.