Scallion-Inspired Environmental Energy Enhanced Solar Evaporator with Integrated Water Transport and Thermal Management

Abstract

Solar-driven interface evaporation is recognized as an efficient and energy-saving strategy to address the global freshwater crisis. However, challenges such as salt crystallization and high energy loss of the evaporators seriously hinder their practical application. In this study, inspired by natural scallion structure, a 3D layered curled cylindrical photothermal interface evaporator using copper sulfide (CuS) and nickel foam (NF) are constructed, achieving an impressive evaporation rate of up to 6.12 kg·m⁻²·h⁻¹ under 1 kW·m⁻² solar irradiation. Further analysis reveals that the layered curled cylindrical structure of the evaporator reduces heat loss to the underlying water, optimizing the balance between water transport and thermal management. Notably, the evaporator demonstrated excellent salt resistance and robust desalination durability for 140 h in 20 wt.% NaCl solution, attributed to the vertical and horizontal water channels. This work guides the design of efficient, salt-resistant solar-driven evaporators for seawater desalination and wastewater treatment in extreme conditions.