(Au@Ag)@Au double shell nanoparticles loaded on rutile TiO2 for photocatalytic decomposition of 2-propanol under visible light irradiation
作者：Sunao Kamimura，Takeshi Miyazaki，Ming Zhang，Yuqing Li，Toshiki Tsubota，Teruhisa Ohno
關鍵字：Photocatalyst,Titanium oxide, Visible light-responsive photocatalyst, Localized surface plasmon resonance
論文來源：期刊
具體來源：Applied Catalysis B: Environmental
發表時間：2016年
We synthesized (core@shell)@shell ((Au@Ag)@Au) nanoparticles (NPs) by a multistep citrate reduction method for utilization as photosensitizers of TiO2. The (Au@Ag)@Au NPs exhibited strong photoabsorption in visible light response due to LSPR excitation of the Ag shell, and its LSPR characteristics were stable under visible light irradiation for a long time because oxidation of the Ag shell was prevented by the outermost Au shell. Furthermore, we successfully loaded (Au@Ag)@Au NPs on rutile TiO2 by an impregnation method. (Au@Ag)@Au/TiO2 could oxidize 2-propanol into acetone and CO2 under visible light irradiation (λ > 440 nm), and its acetone evolution rate was approximately 15-times higher than that of Au/TiO2. From a comparison of action spectra for acetone evolution and the Kubelka–Munk function, it was confirmed that photocatalytic activity of (Au@Ag)@Au/TiO2was induced by photoabsorption based on LSPR excitation of the Ag shell. In addition, photoelectrochemical measurements revealed electron injection from LSPR-excited (Au@Ag)@Au NPs into TiO2 under visible light irradiation. We proposed the photocatalytic reaction process of (Au@Ag)@Au/TiO2 in conjunction with optical, structural and photoelectrochemical properties.