Surface Plasmon-Driven Water Reduction: Gold Nanoparticle Size Matters

• Published in: Journal of the American Chemical Society Vol. 136; no. 28; pp. 9842 - 9845
• Main Authors: Qian, Kun, Sweeny, Brendan C, Johnston-Peck, Aaron C, Niu, Wenxin, Graham, Jeremy O, DuChene, Joseph S, Qiu, Jingjing, Wang, Yi-Chung, Engelhard, Mark H, Su, Dong, Stach, Eric A, Wei, Wei David
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 16.07.2014
• Subjects: electron transfer; energy conversion; gold; nanogold; photocatalysis; photocatalysts; titanium dioxide
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/ja504097v

Water reduction under two different visible-light ranges (λ > 400 nm and λ > 435 nm) was investigated in gold-loaded titanium dioxide (Au-TiO2) heterostructures with different sizes of Au nanoparticles (NPs). Our study clearly demonstrates the essential role played by Au NP size in plasmon-driven H2O reduction and reveals two distinct mechanisms to clarify visible-light photocatalytic activity under different excitation conditions. The size of the Au NP governs the efficiency of plasmon-mediated electron transfer and plays a critical role in determining the reduction potentials of the electrons transferred to the TiO2 conduction band. Our discovery provides a facile method of manipulating photocatalytic activity simply by varying the Au NP size and is expected to greatly facilitate the design of suitable plasmonic photocatalysts for solar-to-fuel energy conversion.