Plasmon-induced artificial photosynthesis

Abstract

We have successfully developed a plasmon-induced artificial photosynthesis system that uses a gold nanoparticle-loaded oxide semiconductor electrode to produce useful chemical energyas hydrogen andammonia. Themost important feature of this systemis that both sides of a strontiumtitanate single-crystal substrate are used without an electrochemical apparatus. Plasmon-induced water splitting occurred even with a minimum chemical bias of 0.23 V owing to the plasmonic effects based on the efficient oxidation of water and the use of platinum as a co-catalyst for reduction. Photocurrent measurements were performed to determine the electron transfer between the gold nanoparticles and the oxide semiconductor. The efficiency ofwater oxidationwas determined through spectroelectrochemical experiments aimed at elucidating the electron density in the gold nanoparticles. A set-up similar to the water-splitting systemwas used to synthesize ammonia via nitrogen fixation using ruthenium instead of platinum as a co-catalyst.