(Invited) In-Situ Raman Observation of Reaction Intermediates at Plasmon-Induced Water Oxidation Processes

Efficient multi-electron transfer reaction is important target for the developments on various energy technologies in future. Plasmon-induced photochemical reaction system should be one of the choices. Although it has been demonstrated that the excitation of localized surface plasmon resonance (LSPR) at Au metal nanoparticle on metal oxide semiconductors enable efficient water oxidation even under near-infrared light illumination, mechanis. In this work, we observed plasmon-induced water oxidation process using in-situ surface enhanced Raman scattering (SERS) measurement. Size-controlled metal nanodimer arrays was fabricated on titanium dioxide single crystalline by angle-resolved nanosphere lithography. The phonon vibrations of metal oxides were observed as the intermediate of water oxidation. The formation of the intermediate at relatively negative potential is attributed to the water oxidation process via holes generated by LSPR. We concluded that novel mechanisms exist for water oxidation on plasmonic electrode, compared with that at bulk Au electrode.