A Robust Solar Evaporator with Hierarchical Architecture for Ultrahigh Efficiency and Large-Scale Zero-Liquid-Discharge Desalination.

Abstract

Solar-driven desalination offers a green and sustainable strategy for solving the issue of freshwater scarcity. However, it remains a challenge to develop a robust evaporator via an eco-friendly strategy, capable of resolving the long-standing trade-off between the water supply, salt accumulation, and thermal localization. Herein, a hierarchical solar-absorbing architecture derived from mycelium is developed for high-performance desalination. With the merits of multi-level spatially low-tortuosity channels, gradient wettability and directional transport, the evaporator achieves an impressive evaporation rate (up to 10.25 kg m^-2 h^-1 for 25 wt.% brine), efficient salt collection (1.95 kg m^-2 h^-1 for 25 wt.% brine), zero liquid discharge desalination, and long-term stability (over 145 h in 10-25 wt.% brine). Moreover, the scaled-up desalination system exhibits an ultrahigh freshwater production rate of 6 kg m^-2 h^-1 and a daily freshwater yield of up to 32 L m^-2 during the outdoor desalination test. A continuous desalination-cultivation platform demonstrates the feasibility of the evaporator for self-sustainable agricultural irrigation. This low-cost, mycelium-based hierarchical architecture opens an avenue to advance green and sustainable strategy for highly efficient and large-scale desalination of high-salinity brine.