Lotus-Inspired Evaporator with Janus Wettability and Bimodal Pores for Solar Steam Generation
Haoyu Zhao, Jie Zhou, Zhi‐Long Yu, Lifeng Chen, Hui‐Juan Zhan, Hong‐Wu Zhu, Jin Huang, Lu‐An Shi, Shu‐Hong Yu
Abstract
Solar thermal conversion (STC) evaporation is a practical and sustainable technology for seawater desalination and sewage abatement. However, both the limited evaporation efficiency and long-term conversion stability restrain its practical application. Herein, a lotus morphology-inspired biomimetic evaporator (MBE) with Janus wettability and bimodal pores is well designed for high-rate and enduring STC evaporation. Just like lotus leaves, the hydrophobic surface of the MBE cuts off the capillarity of water, hence achieving high-efficient salt resistance and solar absorption, while the hydrophilic substance provides fast water transportation. The bimodal-pore structures formed by incorporating lotus root-like mesopores into the 3D truss-like macropores effectively decrease density and thermal conductivity for self-floating and thermal regulation. This results in a low water vaporization enthalpy of 1846 J g−1, leading to a much higher evaporation rate at the same conversion efficiency. This work may open new avenues for developing high-performance evaporation systems.