Adjusting Light Absorption of Defective UiO-66 for Coupling Photothermal Evaporation with Photocatalysis
Solar interfacial evaporation and photocatalysis exhibit intrinsic complementarity in energy utilization pathways and reaction mechanisms. Integrating photocatalysis into interfacial evaporation systems enables a synergistic platform for efficient evaporation and pollutant removal. In this study, a defect-engineering strategy is developed for UiO-66 by covalently anchoring five carboxyl-containing organic dyes into its framework, where steric hindrance and ligand substitution synergistically induce abundant structural defects. This approach yields a series of defect-rich UiO-66 materials with tunable dye loading. Among them, the dye-sensitized UiO-66@dye-2 system demonstrates optimal light absorption capacity and vacancy defects. The dyes act as sensitizers, broadening the light absorption range and accelerating water evaporation, while the defect-inducing dyes introduce abundant trap sites, enabling rapid charge transfer and efficient spatial charge separation. Under 1-sun irradiation, the system achieves an outstanding water evaporation rate with a high solar-to-vapor conversion efficiency of 97.8%, along with excellent photocatalytic performance, achieving 95.4% degradation of phenol pollutants. Notably, it maintains stable degradation performance across highly acidic and alkaline environments, ensuring reliability for long-term operations in complex conditions. This work provides a molecular-level strategy for constructing defect-rich UiO-66 derivatives and offers insights for designing next-generation materials for integrated photothermal-photocatalytic environmental remediation.