This study integrates multi-effect distillation (MED), multi-stage flash (MSF) evaporation, and solar interface evaporation technologies to enhance water purification processes. We evaluate the material and performance of interface evaporators, with a particular focus on managing the energy balance in solar water evaporation. The research further develops thermal regulation in photothermal materials to maximize light absorption, minimize heat loss, and speed up steam conversion. We employ a novel approach using corn starch and ionic liquid-modified silica hydrogels, noted for their hydrophilicity and broad-spectrum light absorption. The goal is to assess these hydrogels for photothermal conversion efficiency and salt resistance, examining their evaporation performance across various media—pure water, highly saline water, and oily wastewater—and their effectiveness in purifying industrial sewage. Monomer [VEIm]Br and cross-linking agent polymerization occurred to prepare the obtained