1. Photo-accelerated water dissociation across one-atom-thick electrodes
- Author
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Cai, J., Griffin, E., Guarochico-Moreira, V., Barry, D., Xin, B., Huang, S., Geim, A. K., Peeters, F. M., and Lozada-Hidalgo, M.
- Subjects
Physics - Chemical Physics ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Recent experiments demonstrated that interfacial water dissociation (H2O = H+ + OH-) could be accelerated exponentially by an electric field applied to graphene electrodes, a phenomenon related to the Wien effect. Here we report an order-of-magnitude acceleration of the interfacial water dissociation reaction under visible-light illumination. This process is accompanied by spatial separation of protons and hydroxide ions across one-atom-thick graphene and enhanced by strong interfacial electric fields. The found photo-effect is attributed to the combination of graphene's perfect selectivity with respect to protons, which prevents proton-hydroxide recombination, and to proton transport acceleration by the Wien effect, which occurs in synchrony with the water dissociation reaction. Our findings provide fundamental insights into ion dynamics near atomically-thin proton-selective interfaces and suggest that strong interfacial fields can enhance and tune very fast ionic processes, which is of relevance for applications in photo-catalysis and designing reconfigurable materials.
- Published
- 2022
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