In situ electron microscopy investigation of Fe(III)-doped TiO2 nanoparticles in an aqueous environment

Three-dimensional networks of Fe(III)-doped TiO2 nanoparticles ( 2 - 4 nm) prepared from organic precursors are detected by Cryo-TEM ( transmission electron microscopy) in an aqueous environment. High-resolution TEM studies show that the nanoparticles prefer to align along their crystallographic orientation. A novel energy transfer mechanism is suggested in which these three-dimensional networks act as antenna systems thus leading to an enhanced photocatalytic activity of the colloidal preparations.