“Matryoshka Doll” Heterostructures Induce Electromagnetic Parameters Fluctuation to Tailor Electromagnetic Wave Absorption

Components manipulation and structure engineering have shown powerful approaches for tailoring electromagnetic (EM) parameters. However, the integration of controllable architectural and compositional complexity into one multiple‐layer heterostructure seems significantly effective but remains a considerable challenge, and correlative quantized modulation of EM parameters is scarce. Herein, three types of metal–organic frameworks (MOFs) hybrids and derived sulfides are ingeniously fabricated by MOF architecture engineering and solvothermal sulfuration. Compared to the random assembly of MOFs in the “Chaotic” structure (Structure 1), the regular arrangement of MOF‐on‐MOF heterostructures in the “Matryoshka doll” structure (Structure 2) guarantees improved lattice strain and defect arising from abundant heterointerfaces in core–shell heterostructure. Impressively, such aforementioned advantages together with sufficiently exposed defect sites and conductivity display an interesting “quantized state” between “0 state” and “1 state” in the subsequent ion exchange process for “Matryoshka doll” structured Zn–Co sulfides, benefiting EM parameters “quantization” and boost electromagnetic wave (EMW) absorption. Further, introducing metal ions in a cation‐doped “Matryoshka doll” structure (Structure 3) subtly optimizes composition and defect, leading to enhanced impedance matching and effective absorption bandwidth of 7.8 GHz at 2.6 mm. This study highlights the significant effect of multiple‐layer heterostructures on EM parameters fluctuation, which is in synergy with lattice defect, sulfur vacancy, and conductivity to tailor desirable EMW absorption capacity.