Aluminum Nanocrystals as a Plasmonic Photocatalyst for Hydrogen Dissociation

• Published in: Nano letters Vol. 16; no. 2; pp. 1478 - 1484
• Main Authors: Zhou, Linan, Zhang, Chao, McClain, Michael J, Manjavacas, Alejandro, Krauter, Caroline M, Tian, Shu, Berg, Felix, Everitt, Henry O, Carter, Emily A, Nordlander, Peter, Halas, Naomi J
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 10.02.2016
• Subjects: Aluminum; Hot electrons; Hydrogen storage; Nanocrystals; Photocatalysis; Photocatalysts; Plasmonics; Surface chemistry; hot electron; interband transition; hydrogen dissociation; aluminum nanocrystals; Plasmonic photocatalysis
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.5b05149

Hydrogen dissociation is a critical step in many hydrogenation reactions central to industrial chemical production and pollutant removal. This step typically utilizes the favorable band structure of precious metal catalysts like platinum and palladium to achieve high efficiency under mild conditions. Here we demonstrate that aluminum nanocrystals (Al NCs), when illuminated, can be used as a photocatalyst for hydrogen dissociation at room temperature and atmospheric pressure, despite the high activation barrier toward hydrogen adsorption and dissociation. We show that hot electron transfer from Al NCs to the antibonding orbitals of hydrogen molecules facilitates their dissociation. Hot electrons generated from surface plasmon decay and from direct photoexcitation of the interband transitions of Al both contribute to this process. Our results pave the way for the use of aluminum, an earth-abundant, nonprecious metal, for photocatalysis.