[9a-W621-1~12] 3.12 Nanoscale optical science and near-field optics

▼ [9a-W621-1] Plasmon-induced Photocurrent Generation on Ga₂O₃ Loaded with Gold Nanoparticles

〇(D)Yaguang Wang¹, Xu Shi¹, Tomoya Oshikiri¹, Kosei Ueno¹, Hiroaki Misawa^1,2 (1.RIES-Hokkaido Univ., 2.National Chiao Tung Univ.)

Keywords:Localized surface plasmon resonance, Interface Modification, Gallium oxide

Ga₂O₃ is a promising photocatalyst with the more negative conduction band compared with commonly used TiO₂ due to its much more negative conduction band position which is beneficial to improving efficient water splitting. In this work, the size effect of Au-NPs and the effect of interface modification on the performance of the plasmonic Ga₂O₃ photoelectrode are investigated.
Different sizes of Au-NPs were obtained from Au film with various thicknesses deposited onto Ga₂O₃ upon annealing process (Au-NPs/Ga₂O₃). The samples with Au-NPs size of 13 nm showed the best photocurrent measured under the conventional three-electrode photoelectrochemical measurement system.
To further improve the oxidation process in the water splitting, a thin TiO₂ layer with several nanometers was deposited on the Au-NPs/Ga₂O₃. The IPCE and absorption of the Au-NPs/Ga₂O₃ system showed an increment compared with samples without the interface modification. Also, the onset potential shifted to positive with modification by TiO₂ on Au-NPs/Ga₂O₃, indicating the positive shift of the flat-band potential of the photoelectrode.