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

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)_0.67S 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)_0.67S 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)_0.67S 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.