Nanostructured TiO2 photocatalyst and pump-probe spectroscopic study

Titanium dioxide (TiO2), with its large band gap, has attracted much attention due to its excellent photocatalytic activity. TiO2 ball-shaped nano-particles were deposited on silicon substrates by a thermal oxidation approach. With an increase in the annealing temperature the surface morphology and the structure of TiO2 remained stable, exhibiting good heat stability; meanwhile, the hydrogen production rate also increased. The femtosecond pump-probe spectroscopic study showed that the lifetime of carriers of the samples as- deposited and post-annealed at different temperatures were longer than 20 ps.