In-situ X-ray absorption fine structure study of TiO₂ nanoparticles under ultraviolet light

The local structural properties of TiO₂ nanoparticles (NPs) were investigated under ultraviolet light (UV) using in-situ X-ray absorption fine structure measurements at the Ti K edge. XAFS analysis showed that the bond lengths of the atomic pairs were distorted by 0.1Å and that the Debye-Waller factors of the atomic pairs were increased substantially under UV light, compared with those of no UV light. These results suggested that the local structural changes were caused by the photocatalyst reactivity of oxygen atoms in the NPs. Unlike other techniques, in-situ XAFS is sensitive to detect local structural changes during the photocatalytic reactivity.