High‐Entropy Reorganization and Core‐Shell Confinement Engineering for Full‐Spectrum Solar Absorption and Spatial Thermal Localization in Dynamic Solar Evaporator

Abstract Conventional photothermal conversion materials are limited by a conflict between broad‐spectrum absorption and low thermal conductivity, restricting their overall performance in solar desalination. Herein, we report a synergistic “high‐entropy reorganization and core‐shell confinement” strategy to synthesize a core‐shell Cu 0.33 (Fe,Co,Ni,Cr) 0.67 S with a chemically homogeneous yet structurally heterogeneous architecture. This design offers three key advantages: (1) Strong hybridization between the 3d orbitals of Fe, Co, Ni, Cr, Cu, and the 3p orbitals of S reconfigures the band structure, which generates a high joint density of states that enables 96.66% average absorbance across the 250–2500 nm wavelength range. (2) Cu 0.33 (Fe,Co,Ni,Cr) 0.67 S possesses greater thermodynamic stability than CuS, as demonstrated by its lower formation energy. (3) Core‐shell interfacial phonon scattering, coupled with high‐entropy‐induced lattice distortion, significantly suppresses thermal conductivity. A photovoltaic‐driven rotating evaporator that integrates Cu 0.33 (Fe,Co,Ni,Cr) 0.67 S achieves a stable evaporation rate of 3.70 kg m −2 h −1 in 20 wt% high‐salinity brine with < 3% decay over 120 h, outperforming other reported high‐entropy‐material‐based evaporators. This work advances the design paradigm for photothermal conversion materials from single‐component modification to a dual‐driven framework of high‐entropy component synergy and core‐shell spatial confinement, providing a transformative solution for stable freshwater production from hypersaline and highly contaminated water sources.