Novel Au/La-SrTiO3 microspheres: Superimposed Effect of Gold Nanoparticles and Lanthanum Doping in Photocatalysis

Abstract

Novel multielement Au/La-SrTiO3 microspheres were synthesized by a solvothermal method using monodisperse gold and La-SrTiO3 nanocrystals as building blocks. The porous Au/La-SrTiO3 microspheres had a large surface area of 94.6 m2 g-1. The stable confined Au nanoparticles demonstrated strong surface plasmon resonance effect, leading to enhanced absorption in a broad UV/Vis/NIR range. Doping of rare-earth metal La also broadened the absorption band to the visible region. Both the conduction and valence bands of Au/La-SrTiO3 microspheres thus show favorable potential for proton reduction under visible light. The superimposed effect of Au nanoparticles and La doping in Au/La-SrTiO3 microspheres led to high photocurrent density in photoelectrochemical water splitting and good photocatalytic activity in photodegradation of rhodamine B. The photocatalytic activities are in the order of the following: Au/La-SrTiO 3 microspheres>Au/SrTiO3 microspheres>La-SrTiO 3 microspheres>SrTiO3 microspheres. Double up: Au/La-SrTiO3 microspheres have highly cylindrical and hierarchically mesoporous structure, affording a large surface area of 94.6 m2 g-1. They demonstrate a unique superimposed effect of Au nanoparticles and La doping, thus displaying much higher photocatalytic activity than pure SrTiO3 microspheres in both photoelectrochemical water splitting and photodegradation of rhodamine B. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.