Tunable electrochemistry with moiré flat bands and topological defects at twisted bilayer graphene

Abstract

Tailoring electron transfer dynamics across solid-liquid interfaces is fundamental to the interconversion of electrical and chemical energy. Stacking atomically thin layers with a very small azimuthal misorientation to produce moiré superlattices enables the controlled engineering of electronic band structures and the formation of extremely flat electronic bands. Here, we report a strong twist angle dependence of heterogeneous charge transfer kinetics at twisted bilayer graphene electrodes with the greatest enhancement observed near the 'magic angle' (~1.1 degrees). This effect is driven by the angle-dependent tuning of moiré-derived flat bands that modulate electron transfer processes with the solution-phase redox couple. Combined experimental and computational analysis reveals that the variation in electrochemical activity with moiré angle is controlled by atomic reconstruction of the moiré superlattice at twist angles <2 degrees, and topological defect AA stacking regions produce a large anomalous local electrochemical enhancement that cannot be accounted for by the elevated local density of states alone. Our results introduce moiré flat band materials as a distinctively tunable paradigm for mediating electrochemical transformations.

21 pages, 5 figures

References in corpus (2)

• The Raman Fingerprint of Graphene
• The crucial role of atomic corrugation on the flat bands and energy gaps of twisted bilayer graphene at the "magic angle" $\theta \sim 1.08^{\circ }$

Cited by in corpus (11)

• Roadmap for Photonics with 2D Materials
• Rotational and Dilational Reconstruction in Transition Metal Dichalcogenide Moiré Bilayers
• Designing Moiré Patterns by Strain
• An atomistic insight into moiré reconstruction in Twisted Bilayer Graphene beyond the magic angle
• Domain-dependent surface adhesion in twisted few-layer graphene: Platform for moiré-assisted chemistry
• Twisto-electrochemical activity volcanoes in Trilayer Graphene
• Optical response of alternating twisted trilayer graphene
• Direct observation of locally modified excitonic effect within a moiré unit cell in twisted bilayer graphene
• Geometrical properties of strained and twisted moiré heterostructures
• Review of the tight-binding method applicable to the properties of moiré superlattices
• Brownian dynamics simulations of electric double-layer capacitors with tunable metallicity