Self-assembled gold nanoparticles on strontium titanate for efficient photocatalytic water oxidization and visible light response

A gold (Au) nanoparticle (NP) supported photocatalyst is synthesized by vapor-depositing Au atoms onto SrTiO3 (100) and the photocatalytic water oxidation efficiency is investigated by measuring the photocurrent. Loading of Au NPs onto SrTiO3 dramatically improves the photocurrent and induces a visible-light response of SrTiO3. Small-sized NPs with plateau shape and larger NPs with spherical shape are more reactive under UV and visible irradiation, respectively. The maximum photocurrents under UV and visible-light illumination approach 7.0 mA cm−2 and 32.0 μA cm−2. The onset of visible light response is attributed to the localized surface plasmon resonance of the Au NPs.