Interfacial electronic heterostructure engineering of cobalt boride nanosheets toward broadband efficient electromagnetic absorption

Vigorous reflection loss (RL), wide bandwidth together with suitable absorption frequency band are key application indicators for cutting-edge electromagnetic (EM) absorbers to avoid EM pollution in the aerospace. However, the rational design of EM absorbers, especially for the integration of multiple properties, remains highly challenging. Here, we report a novel two-dimensional (2D) nanosheets-like heterostructure constructed by a molten salt-assisted dissolution-growth strategy and linked via strong interfacial electronic interactions, namely, cobalt boride (CoB) with boron, nitrogen co-doped carbon (CoB/BNC). Density functional theory (DFT) calculations demonstrate that stable heterointerfaces formed by strong interfacial electronic interactions are beneficial for enriching polarization effects, while contributing sufficient dielectric loss to boost the EM absorption (EMA) performance. Accordingly, the minimum RL (RLmin) of −70.76 dB and effective absorption bandwidth (EAB) of 4.72 GHz are simultaneously accomplished for CoB/BNC at the thickness of 3.48 mm. Moreover, radar cross section (RCS) simulation results confirmed that the as-prepared absorber coating could perfectly suppress the metal scattering sources in different directions. Generally, this work offers an ingenious engineering strategy for the precise synthesis of functional heterostructures, which holds great promise for developing innovative EMA materials in the aerospace.