For some specific catalytic reaction, how to construct active sites on two dimensional materials is of great scientific significance. Dye-sensitized solar cells (DSCs) can be viewed as one representative photovoltaics because in which liquid electrolyte with triiodide/iodide (I3−/I−) as redox couples are involved. In this study, amino-functionalized graphene (AFG) has been designed according to theoretically analyzing iodine reduction reaction (IRR) processes and rationally screening the volcanic plot. Then, such AFG has been successfully synthesized by a simple hydrothermal method and shows high electrocatalytic activity towards IRR when serving as counter electrode in DSCs. Finally, a high conversion efficiency of 7.39% by AFG-based DSCs was obtained, which is close to that using Pt as counter electrode.