Enhancement of Photo-Oxidation Activities Depending on Structural Distortion of Fe-Doped TiO ₂ Nanoparticles

다국어 초록 (Multilingual Abstract)

<P>To design a high-performance photocatalytic system with TiO<SUB>2</SUB>, it is necessary to reduce the bandgap and enhance the absorption efficiency. The reduction of the bandgap to the visible range was investigated with reference to the surface distortion of anatase TiO<SUB>2</SUB> nanoparticles induced by varying Fe doping concentrations. Fe-doped TiO<SUB>2</SUB> nanoparticles (Fe@TiO<SUB>2</SUB>) were synthesized by a hydrothermal method and analyzed by various surface analysis techniques such as transmission electron microscopy, Raman spectroscopy, X-ray diffraction, scanning transmission X-ray microscopy, and high-resolution photoemission spectroscopy. We observed that Fe doping over 5 wt.% gave rise to a distorted structure, i.e., Fe<SUB>2</SUB>Ti<SUB>3</SUB>O<SUB>9</SUB>, indicating numerous Ti<SUP>3+</SUP> and oxygen-vacancy sites. The Ti<SUP>3+</SUP> sites act as electron trap sites to deliver the electron to O<SUB>2</SUB> as well as introduce the dopant level inside the bandgap, resulting in a significant increase in the photocatalytic oxidation reaction of thiol (–SH) of 2-aminothiophenol to sulfonic acid (–SO<SUB>3</SUB>H) under ultraviolet and visible light illumination.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s11671-016-1263-6) contains supplementary material, which is available to authorized users.</P>