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Unveiling a Photoinduced Hydrogen Evolution Reaction Mechanism via the Concerted Formation of Uranyl Peroxide
journal contributionposted on 2020-06-04, 18:40 authored by Enric Petrus, Mireia Segado, Nuno A. G. Bandeira, Carles Bo
We present a density functional theory study for the photochemical water oxidation reaction promoted by uranyl nitrate upon sunlight radiation. First, we explored the most stable uranyl complex in the absence of light. The reaction in a dark environmen proceeds through the condensation of uranyl monomers to form dimeric hydroxo-bridged species, which is the first step toward a hydrogen evolution reaction (HER). We found a triplet-state-driven mechanism that leads to the formation of uranyl peroxide and hydrogen gas. To describe in detail this reaction path, we characterized the singlet and triplet low-lying states of the dimeric hydroxo-bridged species, including minima, transition states, minimal energy crossing points, and adiabatic energies. Our computational results provide mechanistic insights that are in good agreement with the experimental data available.
form dimeric hydroxo-bridged speciesHERtransition statesUranyl PeroxideConcerted Formationadiabatic energiessunlight radiationuranyl monomershydrogen evolution reactiontriplet-state-driven mechanismtheory studyuranyl nitratehydrogen gaswater oxidation reactionuranyl peroxidereaction pathenvironmen proceedsPhotoinduced Hydrogen Evolution Reaction Mechanismdimeric hydroxo-bridged species