The recently synthesized 2D materials formed by group-IV elements, i.e. graphene, silicene and stanene, etc, have caught great reseach interests. Here, we focus on possible exotic superconducting pairing states in the doped cases, induced by interactions. Starting from relevant Hubbard models on the honeycomb lattice for these systems, we adopt different approaches (mainly weak-coupling RPA approach) to study the pairing symmetries. As a result, we predict several different exotic superconducting states on these systems. For the graphene, we predict possible p+ip triplet superconductivity (SC) with high critical temperature for the heavily doped case, due to the flat band bottom.  For the silicene, we propose possible electric-field driven quantum phase transition from d+id singlet chiral pairing state to the f-wave triplet pairing state, taking advantage of the low-buckled structure of the material. Further more, for the bilayer silicene, we found possible d+id chiral pairing state with tunable Tc even for the undoped case, due to the self-doping effect in this material. For the stanene, we predict topological SC with high Chern-number for properly doped case, due to the strong spin-orbit coupling in this material. These predictions are to be verified by experiment