Dresden 2017 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 58: Fluids and Interfaces II

CPP 58.7: Vortrag

Donnerstag, 23. März 2017, 12:15–12:30, ZEU 255

Bridging phases: Permittivity studies at interfaces for ITIES catalysts — •David Egger, Zhu Liu, Christoph Scheurer, and Karsten Reuter — Technische Universität München, Germany

"Interfaces between Two Immiscible Electrolyte Solutions" (ITIES) - typically, between an aqueous and an organic solvent (OS) - have recently emerged as promising environments for electrocatalytic processes. Amphiphilic MoS₂-based complexes at ITIES are of particular interest for photocatalytic water splitting. It is expected that an appropriate bandgap engineering could lead to a further boost in quantum efficiency that renders ITIES-based solar hydrogen generation technologically viable. Approaching this context from the perspective of predictive-quality first-principles electronic structure calculations a major challenge rests in the accurate, yet efficient representation of the effect of the ITIES environment on the catalytic complex. To this end, we present a tailored implicit solvation approach, in which the liquid-liquid interface surrounding the catalytic complex is coarse-grained to a spatially varying dielectric medium. Across interfaces, this transition function exhibits a strong electrostatic correlation, as recently shown for soft polar interfaces in aqueous environment [1]. Based on classical molecular dynamics simulations we present an approach to model consistent permittivity transition functions across the relevant phase interfaces of the ITIES system. We discuss first numerical results for the topologically significant interfaces of MoS₂-water, MoS₂-OS, as well as the triphase point MoS₂-water-OS. [1] A. Schlaich, E.W. Knapp, and R.R. Netz, Phys. Rev. Lett. 117, 048001 (2016).