关键词: 光解水/
金纳米颗粒/
量子选择性/
量子动力学
English Abstract
Water photosplitting: Atomistic mechanism and quantum dynamics
Shen Yu-Tian1,Meng Sheng1,2
1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
2. Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
Received Date:06 July 2018
Accepted Date:30 September 2018
Published Online:05 January 2019
Abstract:Directly splitting water into carbon-free H2 fuel and O2 gases by sunlight is one of the most environmentally-friendly and potentially low cost approaches to solving the grand global energy challenge. Recent progress of electronic structure theory and quantum simulations allow us to directly explore the atomistic mechanism and ultrafast dynamics of water photosplitting on plasmonic nanoparticles. Here in this paper, we briefly introduce the relevant researches in our group. First we propose that the supported gold nanoparticles on oxide thin film/mental should be able to potentially serve as efficient photocatalysts for water splitting. Then, under the light illumination, we identify a strong correlation among light intensity, hot electron transfer rate, and water splitting reaction rate. The rate of water splitting is dependent not only on respective optical absorption strength, but also on the quantum oscillation mode of plasmonic excitation, which can help to design nanoparticles in water photosplitting cells. Finally, we simulate the ultrafast electron-nuclear quantum dynamics of H2 generation with plasmonic gold cluster on a time scale of~100 fs in liquid water. We identify that the water splitting is dominated by field enhancement effect and associated with charge transfer from gold to antibonding orbital of water molecule. Based on all atomistic mechanism and quantum dynamics above, we present a “chain-reaction” H2 production mechanism via high-speed (much higher than their thermal velocity) collision of two hydrogen atoms from different water molecules under light illumination.
Keywords: water photosplitting/
gold nanoparticles/
quantum selectivity/
quantum dynamics
