Hofmeister effect mediated hydrogel evaporator for simultaneous solar evaporation and thermoelectric power generation
writer：Jiaxin Ren a, Ling Chen a, Jiang Gong a,*, Jinping Qu a,b, and Ran Niu a,b,*
keywords：Solar evaporation, Hofmeister effect, porous hydrogel, molecular structure, thermoelectric power
source：期刊
specific source：Chemical Engineering Journal
Issue time：2023年
Porous hydrogel with intrinsic hydrophilicity and reduced vaporization
enthalpy has emerged as a rising star for solar-driven interfacial water
distillation and desalination. However, the development of facile, general and
scalable approaches capable of simultaneously engineering the molecular and
microporous structure is urgently needed for hydrogel evaporators but a
daunting challenge. Herein, a freeze-soak method based on Hofmeister effect is
used to fabricate porous hydrogel evaporators with tunable molecular and
microporous structure in large scale. The interconnected porous structure
endows the hydrogel with adjustable water transport rate and exceptional
desalination performance, while the changeable crystallinity allows the
hydrogel with tunable water states. Benefiting from these properties, the
hydrogel shows a high evaporation rate of 3.52 kg m-2 h-1
with the conversion efficiency of 97.2% under 1 Sun irradiation. Additionally,
the integration of the hydrogel evaporator with a thermoelectric module enables
the low-grade heat to electricity conversion. A power density of 0.65 W m-2
is achieved under 1 Sun irradiation. It is anticipated that the Hofmeister
effect-mediated porous hydrogel without the assistance of
freeze-drying will lay a solid foundation for the industrial fabrication of
hydrogel for energy conversion and storage, environmental remediation, etc.