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Low-Tortuosity Water Microchannels Boosting Energy Utilization for High Water Flux Solar Distillation
journal contribution
posted on 2020-04-01, 09:29 authored by Ying Xu, Chuyang Tang, Jiaxiang Ma, Dongqing Liu, Dianpeng Qi, Shijie You, Fuyi Cui, Yen Wei, Wei WangSolar distillation through photothermal
evaporators has approached
solar light energy (E1) limit under no solar concentration
but still suffers from modest vapor and clean water production. Herein,
a nature-inspired low-tortuosity three-dimensional (3D) evaporator
is demonstrated to significantly improve water production. The solar
evaporator, prepared from polypyrrole-modified maize straw (PMS),
had upright vascular structures enabling high water lifting and horizontal
microgaps facilitating broad water distribution to the out-surface.
Consequently, this novel PMS evaporator dramatically enhanced the
utilization of the solar heat energy stored in the environment (E2) for promoting evaporation. The maximum vapor generation
rate of a single PMS respectively increases 2.5 and 6 times compared
with the conventional 3D evaporators and the planar evaporators of
an identical occupied area. Consequently, a scaled-up PMS array achieved
a state-of-the-art vapor generation rate of 3.0 L m–2 h–1 (LMH) under a simulated condition and a record-high
clean water production of 2.2 LMH for actual seawater desalination
under natural conditions (1 sun intensity). This breakthrough reveals
great potentials for cost-effective freshwater production as well
as the rational design of high-performance photothermal evaporators
for solar distillation.