Sintering-regulated two-dimensional plate@shell basalt@NiO heterostructure for enhanced microwave absorption

The heterostructure has attracted widespread attention in improving microwave absorption due to the unique composition and structure. Herein, a novel two-dimensional (2D) [email protected] [email protected] heterostructure is synthesized through a sequential process of water bath method followed by a sintered operation. The sintering temperature helps regulate the microwave absorption performance by controlling the heterogeneous interface and vacancy defects of [email protected] to optimize the dielectric loss. The RL of the prepared [email protected] with the sintering temperature of 300 °C reaches up to −15.93 dB at 16.13 GHz, which is attributed to the polarization loss enhanced by vacancy defects (O, Ni vacancies) introduced by low-temperature sintering and large heterogeneous contacts constructed by basalt and NiO. Meanwhile, the high concentration of vacancy defects also leads to a large electrical conductivity that positively contributes to dielectric loss. Furthermore, the [email protected] composite possesses relatively low density, high thermal stability and anticorrosion. This finding provides a way for designing the light microwave absorption materials with excellent environmental stability.