La‑doping induced defect dipoles in transition metal molybdate/N‑doped hollow carbon foam for lightweight electromagnetic wave absorption

Electromagnetic wave (EMW) absorbing materials play a vital role in mitigating electromagnetic pollution and advancing stealth and protection technologies. In this study, flake-like transition metal molybdates (RMoO 4 , R=Ni, Co) were loaded onto a three-dimensional N-doped hollow carbon foam (NCF) to construct electromagnetic wave absorbing (EMA) composite materials. Combining density functional theory (DFT) calculations with CST simulations shows that La doping can enriches Ni 3+ /Co 3+ and create charge inhomogeneity with local dipoles, thereby enhancing dielectric loss. It also reduces the density of states near the Fermi level, suppresses continuous conductive pathways, and improves impedance matching. At a low filler loading (4 wt%), La-doped CoMoO 4 /NCF (LCM/NCF), exhibited extremely low reflection loss (−52.40 dB) and broad effective absorption bandwidth (6.08 GHz). Notably, under near infrared irradiation, the surface temperature of the composite can rapidly rise to above 125 °C within 24  s. In simulated seawater, LCM/NCF exhibits outstanding corrosion resistance. This work provides an innovative strategy for designing lightweight, high-efficiency electromagnetic wave absorbers.