From graphene to graphene ribbons: atomically precise cutting via hydrogenation pseudo-crack.

The properties and applications of graphene nanoribbons (GNRs) depend heavily on their shape and size, making precise design and construction at atomic scale significantly important. Herein, we show that pseudo-cracking is a feasible method for creating atomically precise GNRs. By using molecular dynamics (MD) simulation, we find that hydrogenation can act as a pseudo-crack to trigger the fracture of graphene along the hydrogenation line and cut the graphene into a GNR. Precise GNRs with a desired width, edge type and associated properties can be realized in a controllable way by manipulating the position and dimension of the hydrogenation pseudo-crack. We also find that it is better to use hydrogenation pseudo-cracks along the armchair direction to cut graphene at lower forces into GNRs with smooth edges. Our findings suggest a promising approach to cut graphene and other two-dimensional materials into nanoribbons effectively and accurately.