Dissolution Manufacturing Strategy for Designing Efficient and Low Cost Polymeric Solar Water Evaporator

Abstract The scarcity of fresh water is a pressing issue globally, and solar water evaporation technology has emerged as a leading method for producing fresh water. However, the preparation of solar evaporators is hindered by high costs, complexity, and environmental concerns. In this work, a solar evaporator with hierarchical porous structure is prepared using a simple, low‐cost, and environmentally friendly dissolution manufacturing strategy. Excellent photothermal conversion capability and salt drainage performance are found owing to its hierarchical porous structure. The prepared sample exhibits a water evaporation rate of 2.19 kg m⁻² h⁻¹ and achieves evaporation efficiency of 84.3% under one sun. Furthermore, the evaporation rates of the samples in seawater and methylene blue are 2.04, and 1.98 kg m⁻² h⁻¹, respectively. The evaporation rate remains stable after ten evaporation cycles. The strategy also overcomes the dimensional limitations of traditional methods, as large‐size samples prepared by this strategy are successfully evaluated for evaporation experiments with natural seawater under sunny weather, and the quantity of water collected is ≈170 g in 6 h. The proposed strategy will offer not only sustainable water purification technologies, but also new routes for solar water evaporation, solar steam generation, and photothermal drive fields.