Metal-enhanced hydrogenation of graphene with atomic pattern

Graphene hydrogenation is an attractive approach to functionalize graphene. However, the hydrogenating treatment could only be achieved under harsh conditions due to the weak hydrogen affinity of graphene. It has also made the direct writing of electronic circuits on graphene by hydrogenation very difficult. Here we propose a metal-enhanced approach to hydrogenate graphene with atomic pattern that enables to produce hydrogenation pattern on demand. First-principles calculations reveal that certain metals (Cu, Ag, Al) attached to graphene can significantly lower the energy barrier for hydrogen binding process, while the hydrogen binding energy itself is much enhanced. Such metal-promoted hydrogenation is spatially localized, which paves the way to precisely write pre-designed hydrogenation patterns on graphene with well-controlled metallic clusters and tips.