Epitaxial Hexagonal Boron Nitride for Hydrogen Generation by Radiolysis of Interfacial Water

Hydrogen is an important building block in global strategies toward a future green energy system. To make this transition possible, intense scientific efforts are needed, also in the field of materials science. Two-dimensional crystals, such as hexagonal boron nitride (hBN), are very promising in this regard, as it has been demonstrated that micrometer sized flakes are excellent barriers to molecular hydrogen. However, it remains an open question whether large-area layers fabricated by industrially relevant methods preserve such promising properties. In this work, we show that electron-beam-induced splitting of water creates hBN bubbles that effectively store molecular hydrogen for weeks and under extreme mechanical deformation. We demonstrate that epitaxial hBN allows direct visualization and monitoring of the process of hydrogen generation by radiolysis of interfacial water. Our findings show that hBN is not only a potential candidate for hydrogen storage but also holds promise for the development of unconventional hydrogen production schemes.

Automated summary

Hydrogen is a crucial component of green energy systems, and intense scientific efforts are needed in the field of materials science for this development. Two-dimensional crystals like hBN have shown promise as effective barriers for molecular hydrogen. However, it is uncertain if large-area hBN layers fabricated through industrial methods maintain these excellent properties. This study demonstrates that electron-beam-induced splitting of water creates hBN bubbles that can store molecular hydrogen for long periods, even under extreme mechanical deformation. Additionally, the epitaxial hBN allows for the direct visualization and monitoring of hydrogen generation through radiolysis of interfacial water, suggesting that hBN is not only a potential candidate for hydrogen storage but also for unconventional hydrogen production schemes.