Rattan‐Inspired Salt‐Resistant Elevated 3D Solar Evaporators with Multi‐Scale Aligned Fluid Channels for Efficient and Continuous Seawater Desalination
Huawen Liu, Wentao Zhai
Abstract
Abstract Emerging solar desalination technology shows great potential in response to the growing global water crisis owing to its convenience and low environmental impact. Boosting the exposure height of solar evaporators helps enhance evaporation efficiency. However, the elevated 3D solar evaporator confronts the crucial challenges of poor salt tolerance and insufficient fluid transport height. Herein, inspired by natural rattan, a salt‐tolerant elevated 3D solar evaporator with multi‐scale long‐range aligned fluid channels is fabricated by a continuous bubble freeze casting technique. The capillary‐driven vertical transport in aligned fluid channels endows the evaporator with an elevated exposure height, which helps increase environmental energy utilization, breaking the energy conversion efficiency limitation of conventional 2D evaporators. Moreover, the aligned fluid channel helps to quickly replenish the interfacial water loss and reduce the tortuousness of salt return paths to promote salt circulation, overcoming the long‐standing challenge of salt accumulation in traditional elevated 3D solar evaporators. With rattan‐like structures employed, apparent solar‐to‐steam efficiency of 209.3%, and water evaporation rate of 3.51 ± 0.1 kg m −2 h −1 are gained for seawater desalination under 1 sun radiation without salt accumulation. The creation of rattan‐inspired solar evaporators offers important insights into the structure design of efficient and salt‐tolerant elevated 3D solar evaporators.