Hot-Electron-Transfer Enhancement for the Efficient Energy Conversion of Visible Light

• Published in: Angewandte Chemie (International ed.) Vol. 53; no. 42; pp. 11203 - 11207
• Main Authors: Yu, Sungju, Kim, Yong Hwa, Lee, Su Young, Song, Hyeon Don, Yi, Jongheop
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 13.10.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Decay; Electron transfer; Harvesting; Hot electrons; Irradiation; kinetics; nanomaterials; Nanoparticles; Nanostructure; photocatalysis; Plasmonics; Quantum dots; Semiconductors; solar energy conversion; Spectroscopy; surface plasmon resonance; solar energy conversion; nanomaterials; kinetics; photocatalysis; surface plasmon resonance
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201405598

Great strides have been made in enhancing solar energy conversion by utilizing plasmonic nanostructures in semiconductors. However, current generation with plasmonic nanostructures is still somewhat inefficient owing to the ultrafast decay of plasmon‐induced hot electrons. It is now shown that the ultrafast decay of hot electrons across Au nanoparticles can be significantly reduced by strong coupling with CdS quantum dots and by a Schottky junction with perovskite SrTiO3 nanoparticles. The designed plasmonic nanostructure with three distinct components enables a hot‐electron‐assisted energy cascade for electron transfer, CdS→Au→SrTiO3, as demonstrated by steady‐state and time‐resolved photoluminescence spectroscopy. Consequently, hot‐electron transfer enabled the efficient production of H2 from water as well as significant electron harvesting under irradiation with visible light of various wavelengths. These findings provide a new approach for overcoming the low efficiency that is typically associated with plasmonic nanostructures. A core–shell nanostructure with three distinct components enables the efficient production of H2 from water and significant electron harvesting under visible‐light irradiation because of enhanced hot‐electron injection, the formation of a Schottky junction, and high‐performance electron filtering. The electron transfer pathway is elucidated through steady‐state and time‐resolved photoluminescence spectroscopy.