Yan Lei, Xu Jiyu, Wang Fangwei, Meng Sheng
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Collaborative Innovation Centre of Quantum Matter , Beijing 100190, China.
J Phys Chem Lett. 2018 Jan 4;9(1):63-69. doi: 10.1021/acs.jpclett.7b02957. Epub 2017 Dec 18.
Hydrogen gas production from solar water splitting provides a renewable energy cycle to address the grand global energy challenge; however, its dynamics and fundamental mechanism remain elusive. We directly explore by first-principles the ultrafast electron-nuclear quantum dynamics on the time scale of ∼100 fs during water photosplitting on a plasmonic cluster embedded in liquid water. Water molecule splitting is assisted by rapid proton transport in liquid water in a Grotthuss-like mechanism. We identify that a plasmon-induced field enhancement effect dominates water splitting, while charge transfer from gold to the antibonding orbital of a water molecule also plays an important role. "Chain-reaction" like rapid H production is observed via the combination of two hydrogen atoms from different water molecules. These results provide a route toward a complete understanding of water photosplitting in the ultimate time and spatial limit.
