▎ 摘　　要

Graphane is obtained by perfectly hydrogenating graphene. There exists an intermediate material, partially hydrogenated graphene (which we call hydrographene), interpolating from pure graphene to pure graphane. Employing a graph theoretical approach to the site-percolation model, we present an intuitive and physical picture revealing a percolation transition from graphene to graphane. It is demonstrated that hydrographene shows a bulk ferromagnetism based on the Lieb theory. We also propose a weighted percolation model in order to take into account the tendency of hydrogenation to cluster.