A Highly Active Titanium Dioxide Based Visible-Light Photocatalyst with Nonmetal Doping and Plasmonic Metal Decoration

摘要

Since the discovery of its photocatalytic activity under UV light, TiO2 has been widely studied as a photocatalyst in applications such as water splitting and purification. As pristine TiO2 only absorbs UV light, much effort has been devoted to developing visible-light-active TiO2 photocatalysts that can make use of both UV and visible radiation. Many strategies, including metal-ion and nonmetal doping, have been proposed to extend the absorption of TiO2 to the visible spectrum, but, to date, new materials have typically suffered from low doping concentration and/or low stability against photocorrosion. Noble-metal nanoparticles such as Au and Ag have also been used to enhance the activity of photocatalysts in visible light because of their plasmonic properties. In any case, an improved absorption of photons may not necessarily guarantee significantly better photo-catalytic performance because the efficiency of a photocatalyst is also determined by charge separation and transport.