Design of a Separated Solar Interfacial Evaporation System for Simultaneous Water and Salt Collection

Abstract

Solar-driven interfacial evaporation (SIE) is very promising to alleviate the freshwater scarcity issue. However, salt deposition on the sample surface will reduce evaporation performance, and compromised light absorption will result in a low water collection rate in conventional SIE apparatuses. Here, we report the design of a separated SIE system composed of a polypyrrole@Co 3 O 4 @aluminum sheet and a T-shaped superhydrophilic polyethylene/polypropylene nonwoven fabric right under the sheet. The photothermal surface exposed outside the closed SIE system is separated from the evaporation surface. Thus, salt fouling of solar evaporators is thoroughly avoided and the freshwater collection rate is greatly enhanced. Compared with conventional SIE systems, the separated SIE system has many advantages: simultaneous water and salt collection, a long-term stable evaporation rate even for concentrated brine (1.25 kg m −2 h −1 under 1 kW m −2 (1 sun) illumination, 15 wt % NaCl (aq) , ≥120 h), high salt collection efficiency (≥97%), and a high water collection rate under natural sunlight, e.g., 0.72 kg m −2 h −1 in early spring (0.5−0.6 sun, 19−24 °C) and 0.33 kg m −2 h −1 in cold winter (0.3−0.4 sun, −6 to 4 °C). We foresee that the separated SIE system holds great potential for practical freshwater and salt collection from seawater.

Integrated Multi-Layered Fabric with Tunable Water Supply to the Photothermal Conversion Layer for an Efficient Solar Water Evaporation

“…Whether the prepared photothermal material can maintain good cycle stability during the test is an important factor to ensure that it can be further tested outdoors . Excellent sustainable performance can ensure the recycling of solar-driven vapor–liquid interface water evaporation devices and further reduce the use cost. , IMLF5 is cycled with 3.5 % wt saline to determine its durability (Figure a). The experiment is cycled 16 times.…”

“…50 Excellent sustainable performance can ensure the recycling of solardriven vapor−liquid interface water evaporation devices and further reduce the use cost. 51,52 IMLF5 is cycled with 3.5 % wt saline to determine its durability (Figure 8a). The experiment is cycled 16 times.…”

Long-Term Efficient Interfacial Solar Desalination Enabled by a Biomimetic 2D Water-Transport Structure Based on Silicone Nanofilaments

“…Figure 1 shows the schematic diagram of the separated solar evaporator consisting of a photothermal layer on an Al sheet, a 2D-WTS, and a polystyrene foam thermal insulation layer. 30 The horizontal area of 2D-WTS is in close contact with the lower surface of the Al sheet. The assembly process of the separated solar evaporator is shown in Figure S1.…”

Towards highly salt-rejecting solar interfacial evaporation: Photothermal materials selection, structural designs, and energy management

“…A large amount of salt accumulated in a specific site area can ensure that most areas of the evaporators could work efficiently. This site crystallization control technology has been proved effective by researchers and applied in various solar-driven evaporators [44,[137][138][139][140][141]]. As a typical example, in the authors' work, a solar steam generator was created, which realized efficient steam generation and solid salt collection by adjusting the transportation and distribution of salt solution in photothermal materials [137].…”