Localization Of The Photocatalytic Reaction On The Grain Boundary Of Bicrystalline Tio_2

摘要

Bicrystalline rutile TiO_2(001) crystals were employed for the direct observation of grain-boundary effects on the photocatalytic properties of this material. Irradiating the surface of the bicrystal with UV light in aqueous AgNO_3 solution caused photocatalytic reduction of Ag ions, resulting in Ag precipitation on the surface. The Ag precipitation was significantly enhanced at the grain boundary, and an array of large Ag particles was clearly observed. Thus, direct evidence for a charge-separation enhanced photocatalytic reaction caused by the lattice strain localized at the grain boundary was obtained.