Decoupling Efficiency and Scale in Solar Evaporation by Alternating‐Temperature Array Design for Humidity Regulation

ABSTRACT Solar interfacial evaporation technology represents a promising green approach for seawater desalination. However, scaling up this technology has been hindered by a substantial reduction in evaporation efficiency. Through numerical simulations, we systematically identify the primary origin of this performance loss: non‐uniform vapor convection creating a high‐humidity zone over the central region of large‐area evaporators, which strongly suppresses the evaporation process. To address this challenge, we introduce an alternating‐temperature array‐based design that actively regulates interfacial vapor convection. This design not only enhances convective transport but also effectively shifts the high‐humidity zone away from active evaporation areas, thereby mitigating its inhibitory impact. The alternating‐temperature array‐based evaporator fabricated from renewable lignin achieves an evaporation rate 237.6% higher than that of the non‐array evaporator. This study provides both fundamental insights into vapor management in interfacial solar evaporation and a scalable strategy for high‐efficiency, large‐area solar desalination.