The photogalvanic effect (PGE) has been demonstrated to induce pure spin current in low-dimensional spintronic devices with spatial inversion symmetry, independent of photon energy (E_ph) or incident light polarization/phase angles (θ/φ). The electronic properties of one-dimensional systems can be effectively modulated via edge passivation, making them more conducive to realizing pure spin current. This study utilizes first-principles calculations based on density functional theory and the non-equilibrium Green's function method to systematically investigate zigzag graphene and silicene nanoribbons with asymmetric edge passivation by hydrogen and halogen atoms (F, Cl, Br). The calculation results of the band structure, density of states, and magnetic moment reveal that four structures—F-2H 6ZCNR, F-2H 6ZSiNR, Cl-2H 6ZSiNR and Br-2H 6ZSiNR possess two strongly localized, fully spin-polarized (100% spin polarization) states with opposite spin orientations near the Fermi level, classifying them as bipolar spin semiconductors. Based on these structures, optoelectronic devices with spatial inversion symmetry were designed. The study reveals that upon irradiating the device's central region with linearly polarized light (LPL) or elliptically polarized light (EPL) at varied photon energies (E_ph) and incidence angles (θ/φ), photocurrents emerge in both spin channels with equal magnitude but opposite directions when the photon energy exceeds the spin band gap. This makes the total charge current zero but maintains the finite spin current, indicating the successful generation of the pure spin current. Notably, this pure spin current is independent of light polarization type, E_ph and θ/φ. The further analysis of the spin density distribution, band structure and spatial inversion symmetry elucidates the physical mechanism underlying the pure spin current generation. The robustness of the pure spin current arises from the intrinsic bipolar spin states and spatial inversion symmetry of the device. These findings not only theoretically clarify a feasible approach for achieving pure spin current in one-dimensional graphene and silicene nanoribbons but also present a promising strategy for advancing next-generation spintronic devices, quantum computation and nanosensing technologies.