Abstract:The invention of graphene-based two-dimensional (2D) materials with tunable magnetismand spin-polarized transport is important for next-generation spintronic and catalyticapplications. In this work, spin-polarized density functional theory (DFT) is used toinvestigate the adsorption of 3d transition-metal (TM) atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni)on nitrogenated holey graphene (C2N) and its fluorinated derivative C2CF. The TM atomspreferentially bind at pore-centered sites, forming stable complexes with adsorption energiesbetween −2.3 and −5.7 eV. Strong d–p hybridization between TM d states and host C/N/F pstates induces sizable magnetic moments of 0.6–3.8 μB for C2N and 0.4–3.5 μB for C2CF,converting most systems into spin-polarized metals or half-metals. Band-structure, PDOS,spin-density, and Bader charge analyses confirm that magnetism originates mainly from TM d orbitals, with charge transfer from the TM atoms to the host. C2N provides stronger N-coordinated anchoring, whereas the polar C–F environment of C2CF enhances charge transfer and slightly localizes the magnetic moments. These results give TM embedded in C2N andTM embedded in C2CF as promising platforms for tunable magnetism, spintronic devices,and single-atom catalytic applications.