Acceleration effects of phosphate modification on the decay dynamics of photo-generated electrons of TiO2 and its photocatalytic activity.

The surface modification with a proper amount of phosphate accelerates the dynamic decay of photogenerated electrons in the nanocrystalline anatase TiO(2) film in the presence of O(2), consequently prolonging greatly the lifetime of photogenerated holes so as to improve the charge separation of TiO(2) and then its photocatalytic activity for degrading gas-phase acetaldehyde and liquid-phase phenol mainly based on the transient absorption spectra and the measurements of electrochemical O(2) reduction and the produced hydroxyl radical amount. The acceleration effects are attributed to the increased amount of adsorbed O(2) by means of the curves of O(2) temperature-programmed desorption.