Synthesis, Electron Microscopy and Photocatalytic Activity Studies of Hierarchical TiO_2 Based Nanofiber Catalysts for Photocatalysis and Hydrogen-Generation Applications

摘要

A newly developed, focused-jet, vertical style electrospinning process was employed to synthesize nanofibers of TiO_2 doped with 2% and 2.5% w/v Ag nanoparticles. The as-spun nanofibers were calcined at 510 °C for 24 h in a tube furnace, with a ramp-rate of 5 °C/min, to yield polycrystalline nanofibers. Structural characterization of the prepared nanofibers was done using HR-TEM operated at 200 kV. High-resolution lattice-fringe measurements showed the presence of a mixed-phase anatase and rutile TiO_2 nanostructure along with elemental Ag nanoparticles. BET analysis showed an average specific surface-area of 18.31 m~2/g for the catalyst nanofibers. To measure the photocatalytic activity, a model compound, rhodamine-B dye, was used. Experimental results showed decay rates of 10.64 × 10~(-3) min~(-1) and 12.32 × 10~(-3) min~(-1) for the decay of rhodamine-B dye by TiO_2/2% Ag and TiO_2/2.5% Ag nanoparticles respectively.