Multifunctional Solar Evaporator with Adjustable Island Structure Improves Performance and Salt Discharge Capacity of Desalination

Abstract

Interfacial solar steam generation (ISSG) is the main method to get fresh water from seawater or wastewater. The balance between evaporation rate and salt resistance is still a major challenge for ISSG. Herein, a wood aerogel island solar evaporator (WAISE) with tunable surface structure and wettability by synthesizing poly(n‐isopropylacrylamide)‐modified multi‐walled carbon nanotube photothermal layers. Compared to dense surface structure evaporators, interfacial moisture transport, thermal localization, and surface water vapor diffusion of WAISE are greatly promoted, and the evaporation rate of WAISE increased by 87.64%. WAISE allows for record performance of 200 h continuous operation in 20% NaCl solution without salt accumulation. In addition, the photo‐thermal‐electric device is developed based on WAISE with continuous water purification, power generation, and irrigation functions. This work provides a new direction for the development of multifunctional water purification systems.

Temperature-Dependent Structural Properties of Nickel and Cobalt Selenite Hydrates as Solar Water Evaporators

“…A promising route to address the global water crisis lies in the investigation of hydrates-containing compositions for solar-driven water evaporation [ 14 , 15 ]. Hydrate compounds possess crystal lattices that contain water molecules, making them suitable for application as solar water absorbers.…”

Amphiphilic Janus patch-grafted hydrogels for salt-rejecting solar water desalination

“…Several salt-rejection strategies have been explored to design hydrogel evaporators with high evaporation rate and excellent salt ion rejection performance, including diffusion and convection, 20,21 Janus structure, 22–25 salt ion repulsion effect, 26–28 and local crystallization. 29–31 Among these, the Janus hydrogel evaporator with a hydrophobic top layer and a hydrophilic bottom layer was promising, in which the hydrophobic top layer limits salt deposition and the hydrophilic bottom layer allows rapid salt dissolution so that dissolved salt diffuses back to seawater via convection. 32 In particular, the wettability and thickness of the top layer have a significant impact on water evaporation rate.…”