Suppressed recombination of electrons and holes and its role on the improvement of photoreactivity of flame-synthesized TiO2 nanopowders

An in-situ NEXAFS study was performed to directly investigate the change in the hole structures in the conduction band of TiO2 nanopowders synthesized using a flame method under UV irradiation. The anatase/rutile phase boundary was found to suppress the hole–electron recombination, leading to improved photoreactivity of TiO2 nanopowders.