Integration of phase engineering and defect engineering on O-doped 1T/2H MoS2 for boosting electromagnetic wave absorption

Transition metal dichalcogenides (TMDs) with regulated band structures and multilayered structures have attracted considerable interest in microwave absorption materials. However, the rational design of the hierarchical structure with phase and defect from a microscopic perspective remains challenging. Here, the O-doped 1 T/2H MoS 2 heterojunction is successfully fabricated with a hierarchical morphologically controllable 3D flowerlike structure using the cetyltrimethylammonium bromide template method. It is found that the heterogeneous interface between 1 T and 2 H MoS 2 phases can increase interfacial polarization, and the defects with O dopants and vacancies are beneficial to improve dipole polarization and conductive loss. Such a synergism results in a significantly enhanced electromagnetic wave absorption (EMWA) in these O-doped 1 T/2H MoS 2 samples, achieving the minimum reflection loss (RL min ) of −55.28 dB at a matching thickness of 2.53 mm and an effective absorption bandwidth of 5.05 GHz at 1.88 mm in the as-fabricated MS0.3C-40 samples. Meanwhile, the RL min of the as-fabricated MS0.3C-50 samples reaches −55.24 dB at a matching thickness of 2.29 mm with a maximum radar cross-section of 38.72 dB∙m 2 . These findings pave the way for optimizing the EMWA performance of TMDs with the synergism of phase engineering and defect engineering.