Direct observation of suppressed recombination of electron-hole pairs in the TiO2 nanopowders with anatase-rutile interface: in-situ NEXAFS study under UV irradiation

High-performance TiO
2
photocatalysts have been mainly issued in the area of photoactive materials for a long time. The role of anatase-rutile phase boundary on the photoactivity of TiO2 could be demonstrated combining the materials data with NEXAFS results. An interface between anatase and rutile phases (phase boundary) was directly proved to trap the electrons excited from the valance band, for the first time, by in-situ NEXAFS study under UV light irradiation. Long-life electrons in the trap sites contributed to improve drastically the photocatalytic property of TiO
2
nanopowders made by chemical vapor synthesis.