Photoelectrocatalytic studies of mesoporous Au/TiO2 submicro-spheres by XANES
Kai-Siang Yang (楊凱翔)1,2, Meng-Fan Chai (蔡夢帆)3, Ying-Rui Lu (盧英睿)4, Jeng-Lung Chen (陳政龍)4, Chin-Jung Lin (林進榮)3, Ya-Hsuan Liou (劉雅瑄)5, Chung-Li Dong (董崇禮)4, Ting-Shan Chan (詹丁山)4, Chi-Liang Chen (陳啟亮)1*
1Institute of Physics, Academia Sinica, Taipei, Taiwan
2Department of Mechanical Engineering, National Taipei University of Technology, Taipei, Taiwan
3Department of Environmental Engineering, National I-Lan University, I-Lan, Taiwan
4National Synchrotron Radiation Research Center, Hsinchu, Taiwan
5Department of Geosciences, National Taiwan University, Taipei, Taiwan
* presenting author:楊凱翔,
Plasmonic photocatalyst of TiO2 hollow spheres incorporated with different concentration of Au nanoparticles (0.1, 0.25, 0.5, and 1%) were successfully synthesized by a hydrothermal method. The mean diameters of Au particles are 5~10nm on the surface of anatase TiO2 hollow spheres. The results of X-ray absorption spectroscopy (XAS) indicate that the Au ions are nulvalent. Au is expected to provide a conductive path for moving charge carrier upon the illumination. The UV-Visible absorption spectra and the I–V measurements were used to study localized surface plasmon resonance (LSPR) and activity of photoelectrocatalyst. Ex- and in-situ XAS further reveal the electronic/atomic structure and demonstrate the plasmonic effect that is produced by the Au incorporation. The spectra confirm the oxygen vacancies is formed by TiF4 synthesis process and would play a role in the enhancement of the plasmonic resonance and photo-to-current conversion efficiencies.

Keywords: X-ray absorption spectroscopy(XAS), localized surface plasmon resonance (LSPR)