Electron Delocalization Induced by 3d–4f Orbital Hybridization of Co─Ce Atom Pairs Toward Enhanced Electromagnetic Wave Attenuation and Antibacterial Performance

Transition metal single atoms dispersed on nitrogen-doped carbon (NC) can effectively manipulate local charge motions and reinforce polarization responses. However, the limited electron delocalization restricts the further improvements of electromagnetic wave absorption (EMA) capability for single atom systems. Herein, a novel Co─Ce dual atomic configuration anchored on the surface of NC matrix was constructed to regulate the local electron structure. The higher occupied states induced by the Co 3d-Ce 4f orbital hybridization facilitate the formation of polarized electric fields, which in turn strengthens the polarization relaxation and partially repairs the effective electron conduction. Consequently, the CoCe@NC composites achieve a remarkable maximum absorption intensity of -85.1 dB and an expanded absorption bandwidth of 7.6 GHz at 1.7 mm. Meanwhile, the stronger inter-orbital electron interactions promote the local charge transfer, endowing CoCe@NC systems with optimized POD-like catalytic activity and enhanced antibacterial performance against E. coli and S. aureus. This work highlights the potential of 3d-4f orbital hybridization engineering in designing advanced multifunctional EMA materials, which integrate EMW attenuation and antimicrobial properties to tackle multifaceted challenges.