Electronic modulation for balancing oxygen intermediates bending energy over oxygen evolution catalytic active sites is one of the most critical factors but still remains challenging. In this case, yolk-shell Co8FeS8-FexCy was constructed by fast Joul-heating process with dual-ligand PBA as precursor. With the help of Spherical aberration corrected STEM, synchrotron-radiation photoelectron spectroscopy as well DFT calculations, the consecutive manipulation of d-band center for the designed series of Co8FeS8-based samples by introducing the FexCy with varying element ratios was disclosed. The findings confirm that electron modullation of Co8FeS8-FexCy can upshift the d-band center toward Fermi level to optimalize antibonding-orbital occupancy of the metal-O bond, thereby prominently minimizing Gibbs free energy for intermediates in the rate-determining step. Encouragingly, the optimal Co8FeS8-Fe7C3 delivers an significant overpotential (η10) decrease by 118 mV compared with Co8FeS8-C, ultrasmall Tafel slop of 33.4 mV dec-1, along with excellent catalytic durability. Furthermore, it also shows enhanced electromagnetic wave dissipation ability with the minimum reflection loss of −50.72 at 2.03 mm and effective absorption bandwidth of 7.87 GHz at 1.7 mm. This work uncovers the intrinsic regulation mechanism of microcomponent design and opens up a promising prospect for exploring advanced multifunctional materials.