Proton Acceptor near the Active Site Lowers Dramatically the O-O Bond Formation Energy Barrier in Photocatalytic Water Splitting.
Yang ShaoHuub J M de GrootFrancesco BudaPublished in: The journal of physical chemistry letters (2019)
The O-O bond formation process via water nucleophilic attack represents a thermodynamic and kinetic bottleneck in photocatalytic water oxidation because of the considerably high activation free energy barrier. It is therefore of fundamental significance and yet challenging to find strategies to facilitate this reaction. The microscopic details of the photocatalytic water oxidation step involving the O-O bond formation in a catalyst-dye supramolecular complex are here elucidated by density functional theory-based Car-Parrinello molecular dynamics simulations in the presence of an extra proton acceptor. Introducing a proton acceptor group (OH-) in the hydration shell near the catalytic active site accelerates the rate-limiting O-O bond formation by inducing a cooperative event proceeding via a concerted proton-coupled electron-transfer mechanism and thus significantly lowering the activation free energy barrier. The in-depth insight provides a strategy for facilitating the photocatalytic water oxidation and for improving the efficiency of dye-sensitized photoelectrochemical cells.
Keyphrases
- electron transfer
- visible light
- highly efficient
- molecular dynamics simulations
- density functional theory
- reduced graphene oxide
- energy transfer
- induced apoptosis
- solar cells
- molecular docking
- cell cycle arrest
- molecular dynamics
- oxidative stress
- quantum dots
- signaling pathway
- ionic liquid
- optical coherence tomography
- pi k akt
- endoplasmic reticulum stress
- transition metal