Moiré-Induced Enhanced Hydrogen Adsorption on Graphene

Abstract

The periodic patterning induced by moiré superstructures enables the synthesis of spatially functionalized graphene surfaces owing to changes in the local reactivity of the material. However, quantitative characterization of the effect of different moiré patterns remains elusive. By exploiting the large number of moiré superstructures appearing on epitaxial graphene grown on a Pt(111) surface, this stud examines the effect of moiré-induced corrugation on the local reactivity toward hydrogenation. This work combines atomically resolved scanning tunneling microscopy alongside density functional theory and Monte Carlo simulations of hydrogen chemisorption. The findings reveal a more efficient hydrogen adsorption onto moiré patterns compared to flat graphene, with a marked selectivity toward the most topographically protruding areas of the moiré. This moiré-induced enhancement of the hydrogenation efficiency is slightly increased on the most corrugated structures, which also display longer residence times and a higher stability against thermal desorption.

Keywords: graphene; hydrogen; moiré physics; scanning tunneling microscopy.