Unexpected catalytic activity of nanorippled graphene

Significance Graphene, an isolated atomic plane of graphite, is generally expected to inherit most of graphite’s properties. These expectations are reported to be wrong as far as chemical activity of the two materials is concerned. Indeed, graphite is one of the most inert materials known in nature. In contrast, graphene is shown here to dissociate molecular hydrogen as strongly as the best catalysts known for this reaction. This is attributed to the fact that graphene monolayers are not flat (as within graphite) but unavoidably have nanoscale ripples that serve as active sites for hydrogen splitting. The results have implications for all two-dimensional (2D) materials that being inherently nonflat may exhibit chemical and catalytic properties very different from their bulk counterparts.