Plant-mimetic vertical-channel hydrogels for synergistic water purification and interfacial water evaporation.
作者：Ran Niu, Yang Ding, Liang Hao, Jiaxin Ren, Jiang Gong*, Jinping Qu.
關鍵字：solar evaporator, hydrogel
論文來源：期刊
具體來源：ACS Applied Materials & Interfaces
發表時間：2022年
The integration of renewable solar energy-driven interfacial evaporation and
photocatalysis has recently emerged as one of the most promising technologies
for simultaneous freshwater production and pollutant removal. However, the construction
of advanced integrated system with the merit of fast supply of water and
pollutant molecules remains challenging for efficient solar-driven evaporation
and photocatalytic performance. Herein, inspired by the transpiration of plant,
we fabricate a biomimetic, vertically channeled polypyrrole/foam-like carbon
nitride/poly(vinyl alcohol) hydrogel (PCH) by directional freeze-drying. We
prove that the vertically aligned channels not only reduce heat loss and
improve energy conversion efficiency, but also facilitate the
transport of water and organic pollutants to the air-water interface.
Benefiting from the advantages above, the PCH evaporator presents high solar
evaporation efficiency of 92.5%
with an evaporation rate achieving 2.27
kg m-2 h-1 under 1 kW m-2 irradiation, exceeding
many advanced interfacial solar-driven evaporators. Meanwhile, PCH
reaches the degradation efficiency of 90.6% within 1 h when dealing with tetracycline
(a typical antibiotic)-polluted water, remarkably higher than the hydrogel
without vertically aligned channels (68.6%). Furthermore, the as-formed
reactive oxygen species effectively kill Gram-positive and Gram-negative
bacterial in the source water, achieving the all-round water purification. In
outdoor experiment after 11 h sunlight irradiation, the degradation efficiency of tetracycline and freshwater production of the PCH
evaporator rises to 99.0% and 6.2 kg m-2, respectively. This work highlights
the novel biomimetic approach to fabricate multifunctional photothermal
materials for simultaneous freshwater production and polluted-water
remediation.