Photocatalytic Activity Enhancement of Anatase TiO2by Using TiO

Abstract

We employed high-energy ball-milling technique to fabricate TiO/TiO2heterogeneous nanostructures. XRD proved the existence of TiO/TiO2heterogeneous structures. SEM and HRTEM investigation evidenced that the mean particle size and mean grain size of the as-prepared samples are 23 nm and 13 nm, respectively. UV-Vis spectra exhibited that TiO has enhanced the visible light absorption ofTiO2and has changed theEgofTiO2. UPS examination indicated that the electron work function (EWF) of TiO is higher than that ofTiO2. Photocatalytic degradation experiments revealed that an appropriate TiO content can enhance the photocatalytic activity of pure anataseTiO2. The best photocatalytic activity of TiO/TiO2heterogeneous nanostructures is even better than that of Au-depositedTiO2by keeping high degradation efficiency of 93%. The internal electrical field producing in TiO/TiO2heterogeneous nanostructures was considered to be dominantly responsible for the enhanced photocatalytic activity. Therefore, the substitution of TiO with noble metal inTiO2will be widely used in the future due to its low cost. This study also provides a clear direction of enhancing photocatalytic activity ofTiO2: incorporating a guest compound intoTiO2with an appropriate content if the compound has much higher electron work function than that ofTiO2.