Bromination of 2D Materials.
Eva Marie FreibergerJulien SteffenNatalie J WaleskaFelix HemauerValentin SchwaabAndreas GorlingHans-Peter SteinrueckChristian PappPublished in: Nanotechnology (2023)
The adsorption, reaction and thermal stability of bromine on Rh(111)-supported hexagonal boron nitride (h‑BN) and graphene were investigated. Synchrotron radiation-based high-resolution X-ray photoelectron spectroscopy (XPS) and temperature-programmed XPS allowed us to follow the adsorption process and the thermal evolution in situ on the molecular scale. On h‑BN/Rh(111), bromine adsorbs exclusively in the pores of the nanomesh while we observe no such selectivity for graphene/Rh(111). Upon heating, bromine undergoes an on-surface reaction on h‑BN to form polybromides (170 - 240 K), which subsequently decompose to bromide (240 - 640 K), whereby the high thermal stability of Br/h‑BN/Rh(111) suggests strong/covalent bonding. Bromine on graphene/Rh(111), on the other hand, reveals no distinct reactivity except for intercalation of small amounts of bromine underneath the 2D layer at high temperatures. In both cases, adsorption is reversible upon heating. Our experiments are supported by a comprehensive theoretical study. DFT calculations were used to describe the nature of the h‑BN nanomesh and the graphene moiré in detail and to study the adsorption energetics and substrate interaction of bromine. In addition, the adsorption of bromine on h‑BN/Rh(111) was simulated by molecular dynamics using a machine-learning force field.
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Keyphrases
- molecular dynamics
- high resolution
- aqueous solution
- density functional theory
- machine learning
- room temperature
- carbon nanotubes
- walled carbon nanotubes
- computed tomography
- molecular dynamics simulations
- artificial intelligence
- big data
- mass spectrometry
- quantum dots
- magnetic resonance imaging
- radiation induced
- molecular docking
- high speed