Phase Engineering of MoS ₂ via Anderson‐Type Polyoxometalate Precursor for Efficient Electromagnetic Wave Absorption

Abstract Molybdenum disulfide (MoS ₂ ) with tunable phase transformation, especially with high 1T‐phase content, has been a promising electromagnetic wave (EMW) absorber. However, precise regulation of MoS ₂ phase transformation still remain challenges. Herein, a facile Anderson‐type polyoxometalate (XMo ₆ ,X = Cr, Mn, Fe, Co, Ni) precursor strategy is reported to construct phase transformation tunable MoS ₂ ‐based bimetallic sulfide hybridsfor regulating permittivity and EMW absorption. The well‐defined structures and tailorable compositions of XMo ₆ offer the opportunity to conduct controllable regulation on phase engineering of MoS ₂ . The disparity of MoS ₂ and transition metal sulfides (TMSs) in chemical reactivity leads to sulfur vacancy (V _s ), which induces phase transformation of MoS ₂ from 2H to 1T. The tuning of the electronic structure in MoS ₂ enables precise regulation of permittivity, which is further verified by density‐functional theory (DFT) calculations. The optimized FeS/MoS ₂ /carbon fiber powder with richer 1T‐phase, V _s , heterointerfaces and multi‐component, exhibit a minimum reflection loss of −51.82 dB (1.72 mm) and an effective absorption bandwidth of 6.1 GHz (1.64 mm). This work establishes the logical relationship between the intrinsic structure of MoS ₂ and EMW absorption, offering an effective method for regulating permittivity.